This document discusses moisture sensitivity in HMA (hot mix asphalt). It describes several reasons for moisture damage including loss of cohesion in the asphalt binder, loss of adhesion between the binder and aggregate, and degradation of the aggregate. It also discusses factors that influence moisture sensitivity related to the aggregate properties, asphalt binder properties, HMA mix properties, and weather conditions during construction. Methods for adding antistripping additives like liquid antistrips or lime are presented, as well as several tests for evaluating moisture sensitivity like the boiling water test or freeze-thaw pedestal test.
This document discusses modified asphalt binders, which are used to improve the performance of asphalt pavements. Modifiers such as polymers and fillers are added to asphalt binders to increase rutting resistance at warm temperatures and inhibit cracking from traffic and environmental stresses. The document describes different types of modifiers and provides examples of polymeric modifiers. It also discusses traditional testing methods for modified binders and uses microscopy images to illustrate how polymers interact within asphalt binders.
The document discusses the Superpave performance graded specification for asphalt binders. The specification grades asphalt binders based on the climate and expected pavement temperatures. A variety of tests are used to evaluate the binder properties related to different distresses at different temperatures. The rotational viscosity test evaluates workability at construction temperatures. The dynamic shear rheometer test evaluates rutting resistance at high in-service temperatures after both short-term aging from mixing and long-term aging. The bending beam rheometer and direct tension tests evaluate stiffness and strength respectively at low in-service temperatures. Conditioning such as short-term aging with the rolling thin film oven test and long-term aging with the pressure aging vessel better simulate
The document discusses Superpave mix design, which is a performance-based method for designing asphalt concrete mixtures. Some key points:
- Superpave uses the gyratory compactor to simulate field compaction of mixtures, allowing for evaluation of density during the design process.
- The design process involves 4 steps: selecting materials based on traffic and climate conditions, designing the aggregate structure, determining the optimum asphalt binder content, and evaluating moisture susceptibility.
- Key evaluation points on the gyratory compaction curve are Ninitial, Ndesign, and Nmax, which control compactability, expected field density, and maximum allowed density.
- Design traffic level determines the number
This document provides information on cold mix bituminous plant and the cold mix asphalt manufacturing process. It discusses that cold mix asphalt is made by mixing aggregate and emulsified or cutback asphalt at ambient temperatures, as opposed to hot mix asphalt which uses heated aggregates and binder. The document outlines the selection of aggregates, asphalt, additives and mix design considerations for cold mix asphalt. It notes that cold mix asphalt can be used for various pavement applications and provides cost and construction advantages over hot mix asphalt.
The document provides an overview of Superpave mix design methods for hot mix asphalt (HMA). It discusses the goals of using a gyratory compactor to simulate field compaction. The key steps of the Superpave mix design process are selecting materials, designing the aggregate structure, determining the optimum asphalt binder content, and evaluating moisture sensitivity. Sample preparation and determining volumetric properties are also summarized. The Superpave method aims to develop durable, stable HMA mixes through gyratory compaction testing.
The document discusses bituminous mix design and the Marshall mix design method. It describes the objectives of mix design as developing an economical blend of aggregates and asphalt that meets design requirements such as sufficient asphalt, stability, air voids, and workability. The Marshall mix design procedure involves selecting and testing aggregates and asphalt, developing trial blends, compacting specimens, and evaluating properties according to criteria like stability, flow, air voids, and tensile strength ratio. Calculations are also required to determine properties like theoretical maximum density and voids in the mix.
The document discusses the history and evolution of asphalt binder specifications. Early specifications focused on consistency and graded binders based on penetration testing. Later, specifications incorporated viscosity grading which characterizes binders across a range of temperatures relevant to mixing and compaction. Current performance-based specifications further consider aging characteristics by testing rolled thin film oven aged residues. Viscosity grading provides more information on asphalt properties and performance compared to penetration grading. Specifications have evolved with technological advances to better ensure desirable asphalt characteristics for pavement performance.
Introduction to superpave & Performance Grading(P.G)hisham123852
This document provides an overview of the Superpave system for designing asphalt pavements. It describes Superpave as including a new mixture design and analysis system based on pavement performance. The key aspects covered include: Superpave performance grading for asphalt binders based on climatic conditions; tests used for mixture design and performance prediction; simulation of field conditions through laboratory aging and testing at relevant temperatures; and specification of binder grades based on high and low pavement temperatures.
This document discusses modified asphalt binders, which are used to improve the performance of asphalt pavements. Modifiers such as polymers and fillers are added to asphalt binders to increase rutting resistance at warm temperatures and inhibit cracking from traffic and environmental stresses. The document describes different types of modifiers and provides examples of polymeric modifiers. It also discusses traditional testing methods for modified binders and uses microscopy images to illustrate how polymers interact within asphalt binders.
The document discusses the Superpave performance graded specification for asphalt binders. The specification grades asphalt binders based on the climate and expected pavement temperatures. A variety of tests are used to evaluate the binder properties related to different distresses at different temperatures. The rotational viscosity test evaluates workability at construction temperatures. The dynamic shear rheometer test evaluates rutting resistance at high in-service temperatures after both short-term aging from mixing and long-term aging. The bending beam rheometer and direct tension tests evaluate stiffness and strength respectively at low in-service temperatures. Conditioning such as short-term aging with the rolling thin film oven test and long-term aging with the pressure aging vessel better simulate
The document discusses Superpave mix design, which is a performance-based method for designing asphalt concrete mixtures. Some key points:
- Superpave uses the gyratory compactor to simulate field compaction of mixtures, allowing for evaluation of density during the design process.
- The design process involves 4 steps: selecting materials based on traffic and climate conditions, designing the aggregate structure, determining the optimum asphalt binder content, and evaluating moisture susceptibility.
- Key evaluation points on the gyratory compaction curve are Ninitial, Ndesign, and Nmax, which control compactability, expected field density, and maximum allowed density.
- Design traffic level determines the number
This document provides information on cold mix bituminous plant and the cold mix asphalt manufacturing process. It discusses that cold mix asphalt is made by mixing aggregate and emulsified or cutback asphalt at ambient temperatures, as opposed to hot mix asphalt which uses heated aggregates and binder. The document outlines the selection of aggregates, asphalt, additives and mix design considerations for cold mix asphalt. It notes that cold mix asphalt can be used for various pavement applications and provides cost and construction advantages over hot mix asphalt.
The document provides an overview of Superpave mix design methods for hot mix asphalt (HMA). It discusses the goals of using a gyratory compactor to simulate field compaction. The key steps of the Superpave mix design process are selecting materials, designing the aggregate structure, determining the optimum asphalt binder content, and evaluating moisture sensitivity. Sample preparation and determining volumetric properties are also summarized. The Superpave method aims to develop durable, stable HMA mixes through gyratory compaction testing.
The document discusses bituminous mix design and the Marshall mix design method. It describes the objectives of mix design as developing an economical blend of aggregates and asphalt that meets design requirements such as sufficient asphalt, stability, air voids, and workability. The Marshall mix design procedure involves selecting and testing aggregates and asphalt, developing trial blends, compacting specimens, and evaluating properties according to criteria like stability, flow, air voids, and tensile strength ratio. Calculations are also required to determine properties like theoretical maximum density and voids in the mix.
The document discusses the history and evolution of asphalt binder specifications. Early specifications focused on consistency and graded binders based on penetration testing. Later, specifications incorporated viscosity grading which characterizes binders across a range of temperatures relevant to mixing and compaction. Current performance-based specifications further consider aging characteristics by testing rolled thin film oven aged residues. Viscosity grading provides more information on asphalt properties and performance compared to penetration grading. Specifications have evolved with technological advances to better ensure desirable asphalt characteristics for pavement performance.
Introduction to superpave & Performance Grading(P.G)hisham123852
This document provides an overview of the Superpave system for designing asphalt pavements. It describes Superpave as including a new mixture design and analysis system based on pavement performance. The key aspects covered include: Superpave performance grading for asphalt binders based on climatic conditions; tests used for mixture design and performance prediction; simulation of field conditions through laboratory aging and testing at relevant temperatures; and specification of binder grades based on high and low pavement temperatures.
This document discusses materials used in highway construction. It outlines seven major materials: bituminous materials, soil, aggregates, Portland cement concrete, admixtures, pavement marking materials, and structural steel. For each material, it provides details on composition, properties, and relevant tests used for evaluation and quality control of the material. Key tests discussed include moisture content value, California bearing ratio, Los Angeles abrasion value, and specific gravity and water absorption.
OGFC (open-graded friction course) is a pavement surface mixture composed of open gradation and little fine aggregate. It contains a minimum of 18% air voids to provide high skid resistance and drainage. OGFC is used on high traffic roads and areas prone to wet weather accidents to reduce hydroplaning. Its open structure allows water to drain through the pavement to reduce splash and spray. However, OGFC may be more prone to clogging, raveling, and winter maintenance issues compared to dense-graded asphalt.
03-Properties of Asphalt Traditional ( Highway and Airport Engineering Dr. Sh...Hossam Shafiq I
This document discusses the properties and temperature susceptibility of asphalt binders. It describes how binder performance is affected by temperature and loading rate. The stiffness and viscosity of asphalt changes drastically with temperature, going from solid to fluid. The document outlines various test methods and specifications used to characterize and grade asphalt binders, including penetration grades, viscosity grades, and grades based on viscosity after aging. It compares the advantages and disadvantages of different grading systems and specifications.
Comparison of Marshall and Superpave Asphalt Design Methods for Sudan Pavemen...IJSTA
This document compares the Marshall and Superpave asphalt mix design methods. It discusses that the Marshall method currently used in Sudan may be contributing to early pavement failures. The Superpave method is performance-based and better simulates field conditions. The document reviews the key differences between the two methods, such as compaction and specimen dimensions. It then outlines a study conducted in Sudan to directly compare mix designs and properties developed using the Marshall and Superpave methods. The Superpave mixes showed better performance characteristics. Therefore, adopting Superpave in Sudan may improve pavement performance.
This document provides information on testing procedures for road aggregates. It discusses the importance of aggregate testing and outlines various tests performed on aggregates including sieve analysis, aggregate crushing value test, aggregate impact test, abrasion test, soundness test, specific gravity and water absorption tests, and shape tests. For each test type, the document describes the significance, test setup, procedure, observations, and specifications. The goal of the testing is to evaluate aggregates' properties like gradation, strength, shape, durability and suitability for use in pavement construction.
The document discusses the history and methods of hot mix asphalt (HMA) mix designs. It describes the Marshall and Hveem mix design methods, which were developed in the 1930s-1940s to determine the optimal blend of aggregates and asphalt binders. The Marshall method uses compacted cylindrical specimens subjected to impact compaction and stability testing, while the Hveem method employs kneading compaction and a stabilometer to evaluate shear strength. Both aim to achieve sufficient stability, air voids, and workability within the mix. The Superpave gyratory compactor method was later introduced as a improved alternative.
High Temperature High Pressure (HTHP) reservoirs have depths greater than 15,000 feet, pressures over 15,000 psi, and temperatures from 325-500°F. Several considerations are important for cementing in these conditions, including accurate temperature measurement, sufficient slurry density and viscosity, retardation, strength stability additives, filtration control, and preventing gas migration along the cement sheath. Specialty cements and additives can help address gas flow potential from minor to severe levels.
04-Superpave Binder Testing ( Highway and Airport Engineering Dr. Sherif El-B...Hossam Shafiq I
This document describes the tests used in the Superpave asphalt binder specification system. There are 7 tests that characterize properties related to pavement performance, including rotational viscometery for workability, dynamic shear rheometry and bending beam rheometry for rutting and cracking resistance, and pressure aging vessel conditioning to simulate long-term aging. Together these tests aim to improve pavement performance by reducing rutting, fatigue cracking, and low-temperature cracking through measurement and specification of rheological properties of asphalt binders.
The document summarizes the transition in India from using a penetration grading system to a viscosity grading system for bitumen. Some key points:
1) The penetration grading system tested consistency at 25°C, which did not accurately predict performance at higher temperatures. The new viscosity grading system specifies testing at 60°C and 135°C to bound temperature susceptibility.
2) Viscosity grading reduces the number of tests from 12 to 7, lowering costs. It also better controls temperature susceptibility and can be used for polymer-modified bitumen.
3) A study compared bitumen samples from 16 road projects in India under both grading systems. Statistical analysis found the viscosity grade better assessed performance.
The Marshall Method of Mix Design involves selecting an asphalt binder content that provides suitable density and satisfies requirements for minimum stability and flow values. The method includes selecting aggregates and asphalt cement suited for the climate, compacting specimens at varying asphalt contents, and determining volumetrics and performance properties to identify the optimum asphalt content. Specimens are compacted using 35, 50, or 75 blows based on design traffic loads then tested to calculate properties like unit weight, voids, and stability as a function of asphalt content.
This document discusses self-consolidating concrete (SCC), including its design, testing methods, and requirements. SCC is designed to have high flowability and filling ability while maintaining resistance to segregation. Key parameters in designing SCC include aggregate content, paste fraction, powder content, water-cement ratio, and use of high-range water reducers and viscosity-modifying admixtures. Common tests for SCC include slump flow, T500 flow rate, J-Ring, L-Box, and U-Box tests. Visual Stability Index testing is also used to assess resistance to segregation. Proper design and testing help ensure SCC meets requirements for flowability, passing ability, and stability.
The document discusses the Marshall method for designing asphalt concrete mixes. It describes creating trial mixes with varying asphalt contents and testing them for properties like stability, flow, density and voids. The optimum asphalt content is selected based on maximum stability, density and a specified air voids level. Test results and mix proportions are evaluated against specifications to adjust the mix design if needed.
What is the Superpave binder? and how it is superior over traditional Binder and limitation of traditional binder specification. And testing methods and consideration of Superpave Binder.
Introduction to Drilling Fluid /or Mud used to drill Oil and Gas Wells into the sub-surface Hydrocarbon Reservoir. Overview of the rheological properties and general description.
This document discusses different methods for grading bituminous binders, including penetration grading, viscosity grading, and performance grading. Penetration grading uses the penetration test results at 25°C to specify grades. Viscosity grading specifies grades based on viscosity measurements at 60°C and 135°C. Performance grading assigns grades based on the temperature ranges where the binder is expected to perform satisfactorily against rutting, fatigue cracking, and low-temperature cracking. The document also covers specifications, advantages and disadvantages of each grading method, and definitions and measurement of viscosity and its importance in characterizing bitumen properties.
Design and Simulation of Foamed Cement Jobspvisoftware
The nature of foamed cement makes predicting the behavior of compressible fluid very difficult. The use of computer software for pre-job design and analysis has proven to be an effective way for improving the quality and success rate of primary cementing, especially when designing and executing foamed cement jobs.
Making and curing concrete test specimens in theFarrukh Khan
This document provides guidance on making and curing concrete test specimens in the field according to ASTM C 31/C 31M. It describes why test specimens are made, including for acceptance testing of specified strength, checking mixture proportions, and quality control. The key steps covered are: making specimens using molds, consolidating the concrete through rodding and vibration, finishing, initial curing within 48 hours at 16-27°C, final curing by maintaining moisture on the surface at 23°C, and transporting specimens only after 8 hours without jarring or temperature extremes to prevent damage.
DESIGN OF OPEN GRADED FRICTION COURSE MIX USING POLYMER MODIFIED BITUMEN(LDPE)ARUN KANNA
Generation of plastics has increased significantly. Utilization of all types of plastics is unavoidable and it will produce non-biodegradable waste materials. The waste plastics are harmful to the environment if it is not disposed properly. It is very useful in the design and development of high quality flexible road pavement. So, adding the waste plastics as additives in the mix design of the pavement was expected to give good performance when comparing with conventional mix. In this project, advantages and development of modified bitumen is to be studied. The dosage of LDPE modified binder has taken as 6%, 8% &10% in the Open Graded Frictional Course (OGFC) mix design by wet process. The result shows the performance of OGFC mix using PMB.
Bitumen: It is a petroleum Product obtained by distillation of crude petroleum
Bitumen: It is a petroleum Product obtained by distillation of crude petroleum
Bitumen has got different uses. In fact, before used as the principal binder in constructing highways ,bitumen was used in roofing, flooring, bridge, sidewalk surfacing, waterproofing etc purposes.
Bitumen obtained by different ways, vary in property. Even bitumen obtained by refining petroleum crude varies in property depending on the source of crude petroleum and refining process.
Thus, bitumen needs grading, primarily for the different purposes for which it is used, even in highway construction too, the purposes may be different. Secondarily, bitumen refined from different crude oil source and by different refining processes, varies in property. To categories that, bitumen needs to be graded.
On the combined effect of moisture diffusion & cyclic pore pressure generati...Katerina Varveri
In this paper, a simple moisture conditioning protocol which attempts to distinguish the contributions of long- and short-term moisture damage i.e. moisture diffusion and cyclic pore pressure generation in asphalt mixtures is presented. The capability of the proposed protocol to rank various asphalt mixtures of known field performance for their short- and long-term sensitivity to moisture is evaluated on the basis of the Tensile Strength Ratio. Asphalt specimens with different types of aggregates and asphalt binders were conditioned by various combinations of water bath immersion and cyclic pore pressures by means of the Moisture Induced Sensitivity Tester. The results show that the proposed conditioning protocol can be used to evaluate the moisture susceptibility of asphalt mixtures and distinguish among mixtures with different moisture damage susceptibility. In addition, it is shown that the use of cyclic pore pressures has a significant effect and can be used as an accelerated moisture conditioning procedure.
This document discusses materials used in highway construction. It outlines seven major materials: bituminous materials, soil, aggregates, Portland cement concrete, admixtures, pavement marking materials, and structural steel. For each material, it provides details on composition, properties, and relevant tests used for evaluation and quality control of the material. Key tests discussed include moisture content value, California bearing ratio, Los Angeles abrasion value, and specific gravity and water absorption.
OGFC (open-graded friction course) is a pavement surface mixture composed of open gradation and little fine aggregate. It contains a minimum of 18% air voids to provide high skid resistance and drainage. OGFC is used on high traffic roads and areas prone to wet weather accidents to reduce hydroplaning. Its open structure allows water to drain through the pavement to reduce splash and spray. However, OGFC may be more prone to clogging, raveling, and winter maintenance issues compared to dense-graded asphalt.
03-Properties of Asphalt Traditional ( Highway and Airport Engineering Dr. Sh...Hossam Shafiq I
This document discusses the properties and temperature susceptibility of asphalt binders. It describes how binder performance is affected by temperature and loading rate. The stiffness and viscosity of asphalt changes drastically with temperature, going from solid to fluid. The document outlines various test methods and specifications used to characterize and grade asphalt binders, including penetration grades, viscosity grades, and grades based on viscosity after aging. It compares the advantages and disadvantages of different grading systems and specifications.
Comparison of Marshall and Superpave Asphalt Design Methods for Sudan Pavemen...IJSTA
This document compares the Marshall and Superpave asphalt mix design methods. It discusses that the Marshall method currently used in Sudan may be contributing to early pavement failures. The Superpave method is performance-based and better simulates field conditions. The document reviews the key differences between the two methods, such as compaction and specimen dimensions. It then outlines a study conducted in Sudan to directly compare mix designs and properties developed using the Marshall and Superpave methods. The Superpave mixes showed better performance characteristics. Therefore, adopting Superpave in Sudan may improve pavement performance.
This document provides information on testing procedures for road aggregates. It discusses the importance of aggregate testing and outlines various tests performed on aggregates including sieve analysis, aggregate crushing value test, aggregate impact test, abrasion test, soundness test, specific gravity and water absorption tests, and shape tests. For each test type, the document describes the significance, test setup, procedure, observations, and specifications. The goal of the testing is to evaluate aggregates' properties like gradation, strength, shape, durability and suitability for use in pavement construction.
The document discusses the history and methods of hot mix asphalt (HMA) mix designs. It describes the Marshall and Hveem mix design methods, which were developed in the 1930s-1940s to determine the optimal blend of aggregates and asphalt binders. The Marshall method uses compacted cylindrical specimens subjected to impact compaction and stability testing, while the Hveem method employs kneading compaction and a stabilometer to evaluate shear strength. Both aim to achieve sufficient stability, air voids, and workability within the mix. The Superpave gyratory compactor method was later introduced as a improved alternative.
High Temperature High Pressure (HTHP) reservoirs have depths greater than 15,000 feet, pressures over 15,000 psi, and temperatures from 325-500°F. Several considerations are important for cementing in these conditions, including accurate temperature measurement, sufficient slurry density and viscosity, retardation, strength stability additives, filtration control, and preventing gas migration along the cement sheath. Specialty cements and additives can help address gas flow potential from minor to severe levels.
04-Superpave Binder Testing ( Highway and Airport Engineering Dr. Sherif El-B...Hossam Shafiq I
This document describes the tests used in the Superpave asphalt binder specification system. There are 7 tests that characterize properties related to pavement performance, including rotational viscometery for workability, dynamic shear rheometry and bending beam rheometry for rutting and cracking resistance, and pressure aging vessel conditioning to simulate long-term aging. Together these tests aim to improve pavement performance by reducing rutting, fatigue cracking, and low-temperature cracking through measurement and specification of rheological properties of asphalt binders.
The document summarizes the transition in India from using a penetration grading system to a viscosity grading system for bitumen. Some key points:
1) The penetration grading system tested consistency at 25°C, which did not accurately predict performance at higher temperatures. The new viscosity grading system specifies testing at 60°C and 135°C to bound temperature susceptibility.
2) Viscosity grading reduces the number of tests from 12 to 7, lowering costs. It also better controls temperature susceptibility and can be used for polymer-modified bitumen.
3) A study compared bitumen samples from 16 road projects in India under both grading systems. Statistical analysis found the viscosity grade better assessed performance.
The Marshall Method of Mix Design involves selecting an asphalt binder content that provides suitable density and satisfies requirements for minimum stability and flow values. The method includes selecting aggregates and asphalt cement suited for the climate, compacting specimens at varying asphalt contents, and determining volumetrics and performance properties to identify the optimum asphalt content. Specimens are compacted using 35, 50, or 75 blows based on design traffic loads then tested to calculate properties like unit weight, voids, and stability as a function of asphalt content.
This document discusses self-consolidating concrete (SCC), including its design, testing methods, and requirements. SCC is designed to have high flowability and filling ability while maintaining resistance to segregation. Key parameters in designing SCC include aggregate content, paste fraction, powder content, water-cement ratio, and use of high-range water reducers and viscosity-modifying admixtures. Common tests for SCC include slump flow, T500 flow rate, J-Ring, L-Box, and U-Box tests. Visual Stability Index testing is also used to assess resistance to segregation. Proper design and testing help ensure SCC meets requirements for flowability, passing ability, and stability.
The document discusses the Marshall method for designing asphalt concrete mixes. It describes creating trial mixes with varying asphalt contents and testing them for properties like stability, flow, density and voids. The optimum asphalt content is selected based on maximum stability, density and a specified air voids level. Test results and mix proportions are evaluated against specifications to adjust the mix design if needed.
What is the Superpave binder? and how it is superior over traditional Binder and limitation of traditional binder specification. And testing methods and consideration of Superpave Binder.
Introduction to Drilling Fluid /or Mud used to drill Oil and Gas Wells into the sub-surface Hydrocarbon Reservoir. Overview of the rheological properties and general description.
This document discusses different methods for grading bituminous binders, including penetration grading, viscosity grading, and performance grading. Penetration grading uses the penetration test results at 25°C to specify grades. Viscosity grading specifies grades based on viscosity measurements at 60°C and 135°C. Performance grading assigns grades based on the temperature ranges where the binder is expected to perform satisfactorily against rutting, fatigue cracking, and low-temperature cracking. The document also covers specifications, advantages and disadvantages of each grading method, and definitions and measurement of viscosity and its importance in characterizing bitumen properties.
Design and Simulation of Foamed Cement Jobspvisoftware
The nature of foamed cement makes predicting the behavior of compressible fluid very difficult. The use of computer software for pre-job design and analysis has proven to be an effective way for improving the quality and success rate of primary cementing, especially when designing and executing foamed cement jobs.
Making and curing concrete test specimens in theFarrukh Khan
This document provides guidance on making and curing concrete test specimens in the field according to ASTM C 31/C 31M. It describes why test specimens are made, including for acceptance testing of specified strength, checking mixture proportions, and quality control. The key steps covered are: making specimens using molds, consolidating the concrete through rodding and vibration, finishing, initial curing within 48 hours at 16-27°C, final curing by maintaining moisture on the surface at 23°C, and transporting specimens only after 8 hours without jarring or temperature extremes to prevent damage.
DESIGN OF OPEN GRADED FRICTION COURSE MIX USING POLYMER MODIFIED BITUMEN(LDPE)ARUN KANNA
Generation of plastics has increased significantly. Utilization of all types of plastics is unavoidable and it will produce non-biodegradable waste materials. The waste plastics are harmful to the environment if it is not disposed properly. It is very useful in the design and development of high quality flexible road pavement. So, adding the waste plastics as additives in the mix design of the pavement was expected to give good performance when comparing with conventional mix. In this project, advantages and development of modified bitumen is to be studied. The dosage of LDPE modified binder has taken as 6%, 8% &10% in the Open Graded Frictional Course (OGFC) mix design by wet process. The result shows the performance of OGFC mix using PMB.
Bitumen: It is a petroleum Product obtained by distillation of crude petroleum
Bitumen: It is a petroleum Product obtained by distillation of crude petroleum
Bitumen has got different uses. In fact, before used as the principal binder in constructing highways ,bitumen was used in roofing, flooring, bridge, sidewalk surfacing, waterproofing etc purposes.
Bitumen obtained by different ways, vary in property. Even bitumen obtained by refining petroleum crude varies in property depending on the source of crude petroleum and refining process.
Thus, bitumen needs grading, primarily for the different purposes for which it is used, even in highway construction too, the purposes may be different. Secondarily, bitumen refined from different crude oil source and by different refining processes, varies in property. To categories that, bitumen needs to be graded.
On the combined effect of moisture diffusion & cyclic pore pressure generati...Katerina Varveri
In this paper, a simple moisture conditioning protocol which attempts to distinguish the contributions of long- and short-term moisture damage i.e. moisture diffusion and cyclic pore pressure generation in asphalt mixtures is presented. The capability of the proposed protocol to rank various asphalt mixtures of known field performance for their short- and long-term sensitivity to moisture is evaluated on the basis of the Tensile Strength Ratio. Asphalt specimens with different types of aggregates and asphalt binders were conditioned by various combinations of water bath immersion and cyclic pore pressures by means of the Moisture Induced Sensitivity Tester. The results show that the proposed conditioning protocol can be used to evaluate the moisture susceptibility of asphalt mixtures and distinguish among mixtures with different moisture damage susceptibility. In addition, it is shown that the use of cyclic pore pressures has a significant effect and can be used as an accelerated moisture conditioning procedure.
This document summarizes Chevron's methodology for estimating pore pressure from 3D seismic data using multiple layers and centroid effects. It establishes a normal compaction trend from seismic velocities using Promax minimization. Pore pressures are calculated in Gocad accounting for faults and reservoir geometries. The model is calibrated to well data and reservoir simulations. The 3D volume allows pore pressure extraction anywhere and provides discrete estimates of pore pressure, overburden stress, and fracture gradients across the field.
Asphalt mixtures are made up of aggregates, binder and air voids. In order to make a economic and satisfactory performing asphalt mixture the quantity of these individual constituent is required. Mixture design is a tool to determine these optimum quantities.
This document investigates the effects of adding commercial wax additives to asphalt to lower energy consumption during production and paving. It focuses on the wax additives' influence on cracking performance, moisture damage resistance, and low-temperature cracking resistance. Tests were conducted on binders and mixtures with and without wax additives. The results showed that wax additives increased the binder and mixture stiffness and rutting resistance. Wax mixtures also demonstrated improved cracking resistance and moisture damage resistance compared to unmodified mixtures. Tests on the mixtures' low-temperature cracking performance found that wax additives had a minor or no negative effect.
The influence of air void content on moisture damage susceptibility of aspha...Katerina Varveri
Because of the difficulties associated with the generation of finite element meshes based on X-Ray Computed Tomography scans and the extraordinary computational demands in performing 3D finite element analyses, past modelling efforts have focused primarily on 2D representations of asphalt mixtures and have placed no emphasis on the inclusion of the air voids network within the body of an asphalt concrete specimen. A 3D micro mechanical moisture damage model has been developed and implemented in the finite element system CAPA-3D capable of addressing individually the three main phases of asphalt concrete: aggregate, mastic and air voids. 3D finite element meshes of different types of asphalt mixtures were generated on the basis of X-Ray scans. By means of CAPA-3D the significance of the air voids structure in the development of moisture damage in asphalt concrete specimens was demonstrated. Availability of the model enables evaluation and ranking of the contribution of the characteristics of the individual mixture components to the overall mixture moisture resistance.
The document summarizes a study on the combined effects of moisture diffusion and cyclic pore pressure generation in asphalt concrete. The study coupled long-term moisture diffusion processes with short-term pumping actions from wheel loading. Testing with a Moisture Induced Sensitivity Tester distinguished mixtures with different moisture damage susceptibility. Results showed that mixtures with sandstone aggregates, polymer modified binders, and softer bitumen types demonstrated lower moisture damage sensitivity. The testing protocol enabled evaluation of moisture resistance and quantification of short- and long-term moisture damage contributions.
The document describes a framework for advanced 3D centroid modeling calculations using an existing pre-conditioned seismic velocity-based 3D pore pressure volume. Gocad software is used to perform 3D permeability-weighted centroid calculations on mapped horizons, with corrections for dip, in order to provide robust pre-drill pore pressure forecasts. The calculations involve transferring properties from the 3D volume to horizons, correcting for dip, calculating permeability-weighted overpressure using centroid theory equations, and outputting results including centroid pore pressure.
Comparison between Direct and Indirect Composite Resin Restorationswaadkhayat
The document summarizes studies comparing direct and indirect composite restorations. Study 1 measured bond strength of direct and indirect composites to dentin, finding indirect composites had lower bond strength. Study 2 evaluated diametral tensile strength of direct and indirect composites cured with different techniques, with results ranging from 32-70MPa. While indirect techniques minimize polymerization shrinkage, properties are still affected by cement type. Direct composites can provide equal or higher properties than indirect if placed carefully following correct indications.
The document provides information on different types of bitumen and bitumen modification. It discusses natural bitumen, artificial bitumen including straight run bitumen and blown bitumen. It also describes cut back bitumen, emulsions, and modified bitumens including crumb rubber modified bitumen, natural rubber modified bitumen, and polymer modified bitumen. The document lists the advantages of modified bitumens and guidelines for their use. It provides details on consistency tests, performance tests, and grades of different modified bitumens.
A sample lab report on Marshall method of mix design for bituminous mixtures with all calculations.
Please request with your mail ID if you want to download this document.
This document provides information on bitumen, which is used as a binding material in pavements. It discusses the types of bitumen including paving grade, modified, cutback and emulsion. Cutback bitumen has solvents added to increase fluidity while bitumen emulsion uses water. Modified bitumen has additives added to improve properties. The document also describes various tests conducted on bitumen like penetration, ductility, softening point and viscosity to determine hardness and grading. Bitumen requirements include adequate viscosity and adhesion properties. The grading of bitumen depends on the results of penetration tests.
This document discusses bitumen, which is a black or dark brown material derived from petroleum that is used in civil engineering projects like roads and construction. It originates from natural asphalt deposits or is produced through refining crude oil, with the asphalt being the residue left over after distillation. The document outlines the basic refining process and lists some key engineering properties measured for bitumen like penetration value, softening point, and viscosity. It also provides details on common penetration grades available in India.
The document provides information on bitumen mixes used for road construction. It discusses the constituents of bitumen mixes, which include aggregates, filler, and binders like bitumen. It describes different types of mixes like dense graded, stone matrix, and open graded mixes. It also covers characteristics of materials used in mixes and production methods for both hot and cold bitumen mixes. Cold mixes use bitumen emulsions and avoid heating of aggregates and binders.
The document discusses different types of bituminous pavement used in highway engineering. It describes how bituminous pavement is made by mixing heated aggregates like crushed stone with heated asphalt binders. It then lists various types of bituminous pavement like asphalt concrete and discusses their properties and appropriate uses based on traffic levels. The document also discusses factors that can lead to failures of bituminous concrete pavement like excessive loads beyond the pavement's strength.
An immersive workshop at General Assembly, SF. I typically teach this workshop at General Assembly, San Francisco. To see a list of my upcoming classes, visit https://generalassemb.ly/instructors/seth-familian/4813
I also teach this workshop as a private lunch-and-learn or half-day immersive session for corporate clients. To learn more about pricing and availability, please contact me at http://familian1.com
3 Things Every Sales Team Needs to Be Thinking About in 2017Drift
Thinking about your sales team's goals for 2017? Drift's VP of Sales shares 3 things you can do to improve conversion rates and drive more revenue.
Read the full story on the Drift blog here: http://blog.drift.com/sales-team-tips
This document discusses typical distresses that can occur in flexible asphalt pavements and their causes. It describes various types of cracking like fatigue cracking, thermal cracking, block cracking, longitudinal cracking, reflection cracking, as well as other distresses such as rutting, corrugations, slippage, stripping, raveling, reduced skid resistance, roughness, and swelling from frost. Each distress is explained in terms of how it manifests visually and what factors can contribute to its development, such as heavy traffic loads, inadequate drainage, mix design issues, or temperature susceptibility of the asphalt binder. The document provides an overview of the main distresses that can affect flexible pavements and their underlying mechanisms.
General concepts such as workability, aggregate properties, problems with concrete components, admixtures
Note:- The information contained in the document may be incomplete i.e. it may not cover each topic in its entirety
Seminario Internacional:
Dosificación y especificación de hormigón por desempeño
"Buenas Prácticas y Mejoramiento del Desempeño de Hormigones para Pavimentos"
This document provides best practices for designing, constructing, and maintaining concrete pavements. It discusses proper design methods, the importance of a stable foundation system to support the pavement, using appropriate materials like aggregates and cementitious materials, and best practices for mixing, placing, finishing, curing and sawing the concrete. Attention to details at all stages from design to construction is emphasized to achieve long-lasting, durable pavements.
This document discusses mix design and material testing for slurry seal and micro surfacing systems. It provides details on the components of slurry seal and micro surfacing mixes, including aggregate, asphalt emulsion, water, mineral filler, and chemical additives. It also summarizes specifications and purposes of various tests conducted on the materials and mixtures, such as tests for emulsion viscosity and residue, aggregate sand equivalence and gradation, and mix compatibility and performance. The document emphasizes that mix designs provide an indication that quality materials can produce a working system, but contractors must execute the work properly to achieve superior results.
At the California Asphalt Pavement Association (CalAPA) Spring “Technical Tune-Up” Educational Workshop held April 5, 2022 in Brea, a presentation titled "Developing a Successful QA Program for Cold in-place Recycling (CIR) and Cold Central Plant Recycling (CCPR)" was delivered by Fernando Aragon, P.E., G.E., Principal Engineer, Aragon Geotechnical, Inc. Successful CIR implementation requires effective QC testing by the contractor and acceptance testing by the
Owner/Agency. Learn the key components for both of these testing programs that make up a successful QA program. Learn what the new specifications mean for testing and common mistakes to avoid during the
construction of CIR and CCPR projects.
Primary Cementing as a one important operation during drilling. This slide is included fundamental of cementing which helps to petroleum and civil engineering
Curing is maintaining moisture and temperature in concrete to allow hydration and development of properties. Proper curing increases strength, durability, and resistance to damage. Self-curing or membrane curing uses compounds that form a film to retain moisture in concrete without external water. These compounds are hydrophobic molecules that form a monomolecular film to reduce evaporation and allow internal hydration, improving concrete properties where external curing is not possible. Application procedures and different compound types were discussed.
Introduction to Slurry Seal - Todd Vargason, Ergon Asphalt and Emulsionschipseal
A slurry seal is a mixture of asphalt emulsion, crushed aggregate, and other additives that is spread over the surface of a pavement. It fills cracks, adheres firmly to the surface, and provides a weatherproof layer that extends the life of the pavement by 5-7 years. Application is fast, taking only 15 minutes for a typical residential street. It restores texture, protects the pavement from oxidation, and preserves the underlying pavement from further deterioration.
As the saying goes, Good roads cost money, and bad roads cost more. Hear the latest from the world of pavement preservation and how preservation strategies can stretch tight road maintenance dollars, as well as when maintenance becomes rehabilitation.
Curing is maintaining moisture and temperature in concrete to allow desired properties to develop. Proper curing increases strength, durability, and resistance to freezing and thawing. Self-curing concrete uses curing compounds to seal the surface and retain moisture as hydration occurs. Curing compounds form a hydrophobic film that water molecules cannot escape through, reducing evaporation. Common types include acrylic and chlorinated rubber. Proper application ensures a uniform coating is achieved.
Concrete is a common construction material whose properties can be predetermined through design. Key properties include strength, durability, elasticity, shrinkage, creep, and impermeability. Strength is the most important hardened concrete property and is affected by factors like curing conditions, cement type and composition, water-cement ratio, aggregate type and size, and void content. Shrinkage occurs as water leaves the concrete, causing cracks, while creep is permanent deformation under stress over long periods. Proper use of reinforcement, joints, and cement composition can reduce cracking from these effects.
Soil stab use of-new.ppt dr msa edusat.ppt rev 1imtheking2088
This document discusses various methods for soil stabilization using locally available materials, with a focus on using fly ash. The key methods discussed are mechanical stabilization, soil-cement stabilization, soil-lime stabilization, and soil-bitumen stabilization. It provides details on factors that affect each method and suitable applications. Specifically, it describes how fly ash can be used effectively in embankments, subgrades, and various pavement layers to reduce costs while utilizing an industrial waste product.
Self-curing concrete is achieved by means of replacing a part of aggregate by lightweight aggregate or adding chemical admixtures. The self-curing process of concrete takes place from inside to outside, thus reducing the autogenous shrinkage and self-desiccation, especially for the high-performance concrete with relatively low water/binder ratio.
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The document discusses various aspects of asphalt pavement rehabilitation and maintenance using hot mix asphalt overlays. It covers topics such as bituminous patching, surface leveling, cold milling, crack sealing, subsurface drainage, reflection cracking control methods, recycling existing pavement, pavement widening, shoulder rehabilitation, and design of overlays along projects. The key steps for an effective overlay project involve examining preoverlay repairs, subsurface drainage improvements, and methods for controlling reflection cracking from the existing pavement.
This document discusses curing of concrete, which involves maintaining moisture content and temperature to allow desired properties to develop. Proper curing increases strength, durability, and resistance to damage. It describes the hydration process where water reacts with cement compounds. A minimum of 38% water by weight of cement is needed for full hydration. Self-curing concrete uses chemicals to retain mixing water and prevent drying. Membrane-forming compounds form films on concrete surfaces that reduce evaporation and allow curing without applied water. Different types of compounds and their application procedures are outlined.
This document provides information on subfloor preparation and moisture mitigation for concrete slabs. It discusses concrete slab basics, sources of moisture in slabs and testing methodologies. It also reviews treatments for slabs with moisture issues, including penetrating sealers, topical sealers, epoxy coatings, cementitious overlays, and dual-function adhesives. The document also addresses repairing defects in concrete surfaces using cement-based products, and repairing cracks through mechanical preparation and cleaning. Proper subfloor preparation and moisture mitigation is important to prevent future moisture-related flooring issues.
Self curing concrete is , defines self-curing concrete as “the process by which small inclusions dispersed within the concrete hold the water during mixing and up to the setting time and release it during cement hydration.”
The document discusses factors to consider when selecting a sand control completion method. It begins by outlining economic and operational concerns like initial costs, productivity impacts, and well life. It then describes intrinsic rock properties and production factors that influence sand movement. Various completion methods are presented and compared, including open hole, cased hole, standalone screens, gravel packs, frac packs, and more. Key factors that determine success with stand alone screen completions are identified. The document emphasizes that gravel pack sand must be properly sized to control formation sand movement based on research showing poor sand control if the ratio of median gravel pack to formation sand sizes is outside 6 to 13.
This document discusses the fundamentals of rheology and describes various types of rheometers used to measure the rheological properties of asphalt binders. It explains that rheology is the study of flow and deformation and introduces constitutive relationships between force and deformation. It then describes different types of rheometers, including shear rheometers that apply drag or pressure-driven flows, and other rheometers that measure stiffness and strength through bending beam or direct tension tests. Specific examples of equipment are also shown, such as concentric cylinder and parallel plate shear rheometers, a bending beam rheometer, and a direct tension testing device.
The document discusses Superpave asphalt binder specifications. It provides sources of information on Superpave specifications and describes how the performance grade specification system works based on climate. The performance grade takes into account the average 7-day maximum pavement temperature and the 1-day minimum pavement temperature. It then outlines how the Superpave specification addresses key distresses like permanent deformation, fatigue cracking, and low temperature cracking through test requirements on properties like stiffness and viscosity.
The document discusses different types and uses of asphalt binders. It describes how asphalt binder is produced from petroleum crude oil through refining processes like solvent deasphalting and residuum oil supercritical extraction. These processes break down the crude oil into components that are blended to produce asphalt binders of desired properties. The asphalt binders are then used to manufacture hot mix asphalt for paving roads through batch and continuous mix drum plants. Other asphalt products discussed include cutback asphalts and emulsions, along with their compositions and uses.
This document discusses techniques for rehabilitating and maintaining asphalt overlays on concrete pavements, including crack and seat, break and seat, rubblization, and saw and seal. Crack and seat and break and seat involve fracturing concrete slabs to shorten their length and allow for interlocking of pieces. Rubblization involves fracturing concrete into pieces smaller than 9 inches to prevent reflection cracking in overlays. Saw and sealing joints is used to control the rate of deterioration of reflection cracks.
This document discusses hot mix asphalt (HMA) overlays for rehabilitating flexible and rigid pavements. It defines functional and structural overlays, and describes how they are used to address surface defects versus structural defects. The rehabilitation process and factors considered for overlay design like pre-overlay repair, materials selection, and traffic loads are also summarized. Thick and thin overlays as well as reconstruction are presented as options to correct deficiencies.
This document discusses thermal cracking in asphalt pavements. Thermal cracking occurs when temperature decreases cause the pavement to contract and develop tensile stresses that can exceed the material strength. Three factors influence thermal cracking: low pavement surface temperature, cooling rate, and pavement age. The Thermal Stress Restrained Specimen Test (TSRST) directly measures the development of thermal stresses during cooling and identifies the fracture temperature and strength. Test results show lower air voids and some aggregate types can increase fracture temperature and strength. Desirable material properties to resist thermal cracking include low-temperature asphalt binder viscosity and aggregate with high abrasion resistance and low freeze-thaw loss. Pavement structure characteristics like thickness, base
This document discusses test methods for characterizing permanent deformation in hot mix asphalt (HMA). It describes loaded wheel testers like the Asphalt Pavement Analyzer (APA), Hamburg Wheel Tracker, and Purdue Wheel Tracker that apply cyclic wheel loads to HMA samples. Terms related to permanent deformation testing like creep, repeated loading, and dynamic loading are defined. Parameters for different loaded wheel testers and typical APA test results are shown. The document also briefly mentions the gyratory shear compactor, simple shear tester, and uniaxial and triaxial testing for HMA characterization.
This document discusses fatigue cracking in asphalt pavements. It describes how fatigue cracking can start from the bottom of the pavement layer and work its way up, or can start at the top edges due to tire-pavement interactions. Common fatigue testing methods are described, including flexural beam testing where failure is defined as 50% loss of stiffness. Test results depend on whether constant stress or constant strain is used. Other testing methods like cantilevered beam and diametral are also mentioned. Advanced topics covered include notched beam testing, dissipated energy calculations, and models for predicting fatigue life from binder and mix properties.
Stiffness measurements of hot mix asphalt (HMA) mixtures are important for predicting pavement performance and stresses/strains. Various methods exist to measure stiffness through axial, diametral, flexural, or shear testing under repeated or dynamic loading. Stiffness decreases with increasing temperature and air voids, and decreasing asphalt content. Proper characterization of HMA stiffness at different conditions is essential for evaluating fatigue cracking and permanent deformation.
This document discusses quality control and quality assurance control charts. It explains that control charts can be used to monitor processes and detect variation, including chance causes and assignable causes. Control charts have benefits like early detection of issues, establishing process capability, and providing a permanent record of quality. Examples are provided of how to construct X-bar and R control charts and interpret the results to determine whether a process is in statistical control.
This document discusses quality control and quality assurance procedures for obtaining representative samples of asphalt mixtures and their components. It describes how to properly sample materials at different stages, including at plants, trucks, and roadways. The key aspects covered are sampling locations and techniques, sample size requirements, handling and storage of samples, and potential issues that can arise from improper sampling procedures like segregation. Maintaining representative samples is important for ensuring accurate test results and mixture quality.
This document discusses quality control and quality assurance sampling procedures for construction projects. It addresses requirements for a sampling program, including frequency, location, and size of samples. Different types of sampling are described, such as judgment, quota, systematic, stratified, and random sampling. Random sampling is preferable to avoid bias, and it is best to use random number tables to select sample locations. Stratified random sampling involves dividing a construction site into sublots for sampling. The document provides an example of how to use random numbers to select sample locations within sublots for both roadway and hot mix asphalt plant sampling.
This document discusses basic concepts of statistics as they relate to quality control and quality assurance in construction. It explains that variability is inherent in all materials and processes, but can be controlled. Sources of variability include sampling, testing, materials, and construction methods. The goal of quality control/quality assurance is to reduce variability as much as possible by addressing these sources. Key statistical terms discussed include mean, median, range, variance, precision, accuracy, and bias. Frequency histograms are presented as a tool to visualize variability in data.
This document provides an overview of quality control and quality assurance procedures for construction projects. It discusses different types of specifications like proprietary, method, and end result specifications. It also covers topics like process control, acceptance testing, sampling procedures, warranties, and reasons for sampling materials. The overall purpose is to introduce fundamental concepts regarding specifications, testing, and quality assurance/quality control as they relate to construction quality management.
The document discusses acceptance and compliance procedures for hot mix asphalt. It explains how specification limits are set using typical industry standard deviations and allowing three standard deviations from the target value. It also introduces the concept of percent within limits (PWL) which is used to determine payment based on both the accuracy and precision of the test results. The PWL is calculated using quality indices determined from the test average, standard deviation, and specification limits. Examples are provided to demonstrate calculating quality indices and determining the PWL.
The document provides an overview of asphalt plants, outlining their history from the original 1900 patent for bitulithic pavement to modern high production plants. It discusses the acquisition of APAC by Oldcastle Materials Group in 2006, making it a subsidiary of CRH and part of Oldcastle Materials Group which supplies aggregates, asphalt, and ready-mix concrete. The overview also describes the typical components and processes involved in modern asphalt plants, including material blending, drum drying and mixing, burners, environmental controls, and computerized control systems.
This document discusses types of compaction equipment used in construction projects, including static steel wheel rollers, pneumatic rubber-tired rollers, and vibratory rollers. It describes how each type of roller compacts materials through applied contact pressure and identifies key variables that impact compaction, such as roller speed, number of coverage passes, and compaction pattern. The document also explains how construction crews use test strips to establish effective rolling patterns and determine the number of coverages needed to ensure required material density is achieved.
This document discusses compaction of hot mix asphalt (HMA) mixes. It describes the objective of compaction as improving the mechanical stability, resistance to deformation, and fatigue resistance of HMA mats while reducing moisture penetration and cracking. Factors that affect compaction include the properties of materials used, environmental variables like temperature and wind, and laydown site conditions. The document outlines safety considerations, the typical compaction process using different types of rollers, and definitions of key terms. It explains how factors like layer thickness, mix temperature, and base conditions impact compaction efforts.
This document discusses the placement of hot mix asphalt (HMA) mixes using pavers. It describes the components and operation of pavers, including the hopper, conveyors, augers, screed, and tow point. It explains how pavers maintain the proper depth and grade of the mat being placed, and factors that influence screed control like material flow, angle of attack, and pre-compaction. It also covers grade reference systems, production balancing, and safety considerations for HMA placement.
This document discusses the delivery and trucking of hot mix asphalt (HMA) mixes. It covers the objective of HMA delivery, types of haul trucks and their capacities, proper loading and operating techniques for haul trucks, the use of material transfer vehicles to balance production between trucks and paving, and ensuring HMA is kept at the proper temperature during transport. It also addresses tarping loads and questions related to HMA delivery.
How to Interpret Trends in the Kalyan Rajdhani Mix Chart.pdfChart Kalyan
A Mix Chart displays historical data of numbers in a graphical or tabular form. The Kalyan Rajdhani Mix Chart specifically shows the results of a sequence of numbers over different periods.
Monitoring and Managing Anomaly Detection on OpenShift.pdfTosin Akinosho
Monitoring and Managing Anomaly Detection on OpenShift
Overview
Dive into the world of anomaly detection on edge devices with our comprehensive hands-on tutorial. This SlideShare presentation will guide you through the entire process, from data collection and model training to edge deployment and real-time monitoring. Perfect for those looking to implement robust anomaly detection systems on resource-constrained IoT/edge devices.
Key Topics Covered
1. Introduction to Anomaly Detection
- Understand the fundamentals of anomaly detection and its importance in identifying unusual behavior or failures in systems.
2. Understanding Edge (IoT)
- Learn about edge computing and IoT, and how they enable real-time data processing and decision-making at the source.
3. What is ArgoCD?
- Discover ArgoCD, a declarative, GitOps continuous delivery tool for Kubernetes, and its role in deploying applications on edge devices.
4. Deployment Using ArgoCD for Edge Devices
- Step-by-step guide on deploying anomaly detection models on edge devices using ArgoCD.
5. Introduction to Apache Kafka and S3
- Explore Apache Kafka for real-time data streaming and Amazon S3 for scalable storage solutions.
6. Viewing Kafka Messages in the Data Lake
- Learn how to view and analyze Kafka messages stored in a data lake for better insights.
7. What is Prometheus?
- Get to know Prometheus, an open-source monitoring and alerting toolkit, and its application in monitoring edge devices.
8. Monitoring Application Metrics with Prometheus
- Detailed instructions on setting up Prometheus to monitor the performance and health of your anomaly detection system.
9. What is Camel K?
- Introduction to Camel K, a lightweight integration framework built on Apache Camel, designed for Kubernetes.
10. Configuring Camel K Integrations for Data Pipelines
- Learn how to configure Camel K for seamless data pipeline integrations in your anomaly detection workflow.
11. What is a Jupyter Notebook?
- Overview of Jupyter Notebooks, an open-source web application for creating and sharing documents with live code, equations, visualizations, and narrative text.
12. Jupyter Notebooks with Code Examples
- Hands-on examples and code snippets in Jupyter Notebooks to help you implement and test anomaly detection models.
In the realm of cybersecurity, offensive security practices act as a critical shield. By simulating real-world attacks in a controlled environment, these techniques expose vulnerabilities before malicious actors can exploit them. This proactive approach allows manufacturers to identify and fix weaknesses, significantly enhancing system security.
This presentation delves into the development of a system designed to mimic Galileo's Open Service signal using software-defined radio (SDR) technology. We'll begin with a foundational overview of both Global Navigation Satellite Systems (GNSS) and the intricacies of digital signal processing.
The presentation culminates in a live demonstration. We'll showcase the manipulation of Galileo's Open Service pilot signal, simulating an attack on various software and hardware systems. This practical demonstration serves to highlight the potential consequences of unaddressed vulnerabilities, emphasizing the importance of offensive security practices in safeguarding critical infrastructure.
Taking AI to the Next Level in Manufacturing.pdfssuserfac0301
Read Taking AI to the Next Level in Manufacturing to gain insights on AI adoption in the manufacturing industry, such as:
1. How quickly AI is being implemented in manufacturing.
2. Which barriers stand in the way of AI adoption.
3. How data quality and governance form the backbone of AI.
4. Organizational processes and structures that may inhibit effective AI adoption.
6. Ideas and approaches to help build your organization's AI strategy.
Discover top-tier mobile app development services, offering innovative solutions for iOS and Android. Enhance your business with custom, user-friendly mobile applications.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/how-axelera-ai-uses-digital-compute-in-memory-to-deliver-fast-and-energy-efficient-computer-vision-a-presentation-from-axelera-ai/
Bram Verhoef, Head of Machine Learning at Axelera AI, presents the “How Axelera AI Uses Digital Compute-in-memory to Deliver Fast and Energy-efficient Computer Vision” tutorial at the May 2024 Embedded Vision Summit.
As artificial intelligence inference transitions from cloud environments to edge locations, computer vision applications achieve heightened responsiveness, reliability and privacy. This migration, however, introduces the challenge of operating within the stringent confines of resource constraints typical at the edge, including small form factors, low energy budgets and diminished memory and computational capacities. Axelera AI addresses these challenges through an innovative approach of performing digital computations within memory itself. This technique facilitates the realization of high-performance, energy-efficient and cost-effective computer vision capabilities at the thin and thick edge, extending the frontier of what is achievable with current technologies.
In this presentation, Verhoef unveils his company’s pioneering chip technology and demonstrates its capacity to deliver exceptional frames-per-second performance across a range of standard computer vision networks typical of applications in security, surveillance and the industrial sector. This shows that advanced computer vision can be accessible and efficient, even at the very edge of our technological ecosystem.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/temporal-event-neural-networks-a-more-efficient-alternative-to-the-transformer-a-presentation-from-brainchip/
Chris Jones, Director of Product Management at BrainChip , presents the “Temporal Event Neural Networks: A More Efficient Alternative to the Transformer” tutorial at the May 2024 Embedded Vision Summit.
The expansion of AI services necessitates enhanced computational capabilities on edge devices. Temporal Event Neural Networks (TENNs), developed by BrainChip, represent a novel and highly efficient state-space network. TENNs demonstrate exceptional proficiency in handling multi-dimensional streaming data, facilitating advancements in object detection, action recognition, speech enhancement and language model/sequence generation. Through the utilization of polynomial-based continuous convolutions, TENNs streamline models, expedite training processes and significantly diminish memory requirements, achieving notable reductions of up to 50x in parameters and 5,000x in energy consumption compared to prevailing methodologies like transformers.
Integration with BrainChip’s Akida neuromorphic hardware IP further enhances TENNs’ capabilities, enabling the realization of highly capable, portable and passively cooled edge devices. This presentation delves into the technical innovations underlying TENNs, presents real-world benchmarks, and elucidates how this cutting-edge approach is positioned to revolutionize edge AI across diverse applications.
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
Conversational agents, or chatbots, are increasingly used to access all sorts of services using natural language. While open-domain chatbots - like ChatGPT - can converse on any topic, task-oriented chatbots - the focus of this paper - are designed for specific tasks, like booking a flight, obtaining customer support, or setting an appointment. Like any other software, task-oriented chatbots need to be properly tested, usually by defining and executing test scenarios (i.e., sequences of user-chatbot interactions). However, there is currently a lack of methods to quantify the completeness and strength of such test scenarios, which can lead to low-quality tests, and hence to buggy chatbots.
To fill this gap, we propose adapting mutation testing (MuT) for task-oriented chatbots. To this end, we introduce a set of mutation operators that emulate faults in chatbot designs, an architecture that enables MuT on chatbots built using heterogeneous technologies, and a practical realisation as an Eclipse plugin. Moreover, we evaluate the applicability, effectiveness and efficiency of our approach on open-source chatbots, with promising results.
zkStudyClub - LatticeFold: A Lattice-based Folding Scheme and its Application...Alex Pruden
Folding is a recent technique for building efficient recursive SNARKs. Several elegant folding protocols have been proposed, such as Nova, Supernova, Hypernova, Protostar, and others. However, all of them rely on an additively homomorphic commitment scheme based on discrete log, and are therefore not post-quantum secure. In this work we present LatticeFold, the first lattice-based folding protocol based on the Module SIS problem. This folding protocol naturally leads to an efficient recursive lattice-based SNARK and an efficient PCD scheme. LatticeFold supports folding low-degree relations, such as R1CS, as well as high-degree relations, such as CCS. The key challenge is to construct a secure folding protocol that works with the Ajtai commitment scheme. The difficulty, is ensuring that extracted witnesses are low norm through many rounds of folding. We present a novel technique using the sumcheck protocol to ensure that extracted witnesses are always low norm no matter how many rounds of folding are used. Our evaluation of the final proof system suggests that it is as performant as Hypernova, while providing post-quantum security.
Paper Link: https://eprint.iacr.org/2024/257
"Frontline Battles with DDoS: Best practices and Lessons Learned", Igor IvaniukFwdays
At this talk we will discuss DDoS protection tools and best practices, discuss network architectures and what AWS has to offer. Also, we will look into one of the largest DDoS attacks on Ukrainian infrastructure that happened in February 2022. We'll see, what techniques helped to keep the web resources available for Ukrainians and how AWS improved DDoS protection for all customers based on Ukraine experience
What is an RPA CoE? Session 1 – CoE VisionDianaGray10
In the first session, we will review the organization's vision and how this has an impact on the COE Structure.
Topics covered:
• The role of a steering committee
• How do the organization’s priorities determine CoE Structure?
Speaker:
Chris Bolin, Senior Intelligent Automation Architect Anika Systems
Essentials of Automations: Exploring Attributes & Automation ParametersSafe Software
Building automations in FME Flow can save time, money, and help businesses scale by eliminating data silos and providing data to stakeholders in real-time. One essential component to orchestrating complex automations is the use of attributes & automation parameters (both formerly known as “keys”). In fact, it’s unlikely you’ll ever build an Automation without using these components, but what exactly are they?
Attributes & automation parameters enable the automation author to pass data values from one automation component to the next. During this webinar, our FME Flow Specialists will cover leveraging the three types of these output attributes & parameters in FME Flow: Event, Custom, and Automation. As a bonus, they’ll also be making use of the Split-Merge Block functionality.
You’ll leave this webinar with a better understanding of how to maximize the potential of automations by making use of attributes & automation parameters, with the ultimate goal of setting your enterprise integration workflows up on autopilot.
3. 3HMA Characterization Moisture Sensitivity
Reasons for Damage
• Loss of cohesion in asphalt binder film
• Failure of adhesive bond
• Degradation of aggregate
• Freeze/thaw
4. 4HMA Characterization Moisture Sensitivity
Loss of Cohesion
(Spontaneous Emulsification)
• Inverted emulsion
• Aggravated by
presence of emulsifiers
• e.g. clays, additives
• Loss of stiffness and
strength in asphalt
binder
5. 5HMA Characterization Moisture Sensitivity
Loss of Adhesion
Moist Aggregates
• Internal moisture
disrupts asphalt
binder film
• Most states have
max. moisture
content requirement
on fresh HMA
6. 6HMA Characterization Moisture Sensitivity
Loss of Adhesion
Hydraulic Scour
• Traffic-induced movement of water “scrubs” asphalt
binder off of aggregate
Stress as tire passes
7. 7HMA Characterization Moisture Sensitivity
Loss of Adhesion
Pore Water Pressure
• Usually traffic-related
• Voids decrease and
water is trapped
• Moisture gets
“pressed” to aggregate
surface through
breaks in film
8. 8HMA Characterization Moisture Sensitivity
Theories of Adhesion
• Mechanical adhesion
• Chemical reaction
• Surface energy
• Molecular orientation
10. 10HMA Characterization Moisture Sensitivity
Chemical Reaction
• Better adhesion with basic rather than acidic
aggregates
• Basic
•pH > 7
•Positive charge
• Siliceous aggregates tend to strip
• Mixed results and findings in literature
12. 12HMA Characterization Moisture Sensitivity
Examples of Stripping Potential for
Various Minerals and Aggregates
Slight Moderate Severe
Hornblende Quartz Quartz
Basalt Basalt Granite
Siliceous river gravel Quartzite
Granite Gneiss
Limestone Limestone Chert
Sandstone
13. 13HMA Characterization Moisture Sensitivity
Weathering of Aggregate
• Over time, aggregate is exposed to numerous cycles of
varying temp. and humidity
• Outermost adsorbed water molecules are partially
replaced or covered by organic contaminates
• Absorbs oils from air
• Helps improve wetting by asphalt binder
• Stockpiled agg more resistant to stripping than freshly
cleaved rock
14. 14HMA Characterization Moisture Sensitivity
Surface Energy Theory
• Wetting ability of asphalt binder
• Related to viscosity
• Water better than asphalt binder
• Higher surface tension = better adhesion
• Water will displace asphalt binder due to higher
tension
16. 16HMA Characterization Moisture Sensitivity
Liquid Antistripping Additives
• Surface-active agents
• Reduce the surface tension between agg
and asphalt binder
• Give surface charge opposite of aggregate
• Amines most commonly used
•Form positive ion (R-NH3
+
) when
combined with water or acid
17. 17HMA Characterization Moisture Sensitivity
Lime as an Additive
• Lime
• Hydrated lime Ca (OH)2
• Quick lime CaO
• Hydrated lime reacts with most silicate agg.
• Crust of calcium hydroxy silicate
• Strong bond with agg
• Sufficient porosity to allow pen. of AC
• Carboxylic acids and 2-quinlenes of AC
absorbed
• Forms insoluble calcium salt
18. 18HMA Characterization Moisture Sensitivity
Methods of Adding Lime
• Dry
• Loss of lime in plant
• Results not consistent
• Hydrated lime slurry
• Additional water needed
•Reduces production rates
•Increases fuel costs
19. 19HMA Characterization Moisture Sensitivity
Methods of Adding Lime (Continued)
• Dry hydrated lime added to damp agg
• 3-5% moisture
• Mixing in pug mill or tumble mixer
• Quicklime slurry
• Yield of hydrated lime approx. 25% greater for
similar cost
• Exothermic (very)
20. 20HMA Characterization Moisture Sensitivity
HMA Factors Which Influence
Moisture
• Aggregates
• Surface texture (Rough)
• Porosity
• Mineralogy
• Coatings (Clean)
• Surface moisture (Low)
• Surface chemical composition
( ) = Desirable, no info = no consensus
21. 21HMA Characterization Moisture Sensitivity
HMA Factors Which Influence
Moisture
(Continued)
• Asphalt cement
• Viscosity (High)
• Surface chemistry
• Composition
• HMA
• Voids (Low)
• Gradation (Dense)
( ) = Desirable, no info = no consensus
22. 22HMA Characterization Moisture Sensitivity
HMA Factors Which Influence
Moisture
(Continued)
• Weather Conditions
• Temperature during construction (Warm)
• Rainfall during construction (None)
• Rainfall following construction (Min.)
• Freeze/thaw following construction (Min.)
( ) = Desirable, no info = no consensus
23. 23HMA Characterization Moisture Sensitivity
Boiling Water Test
• Subjects HMA loose mix to boiling water for 10
minutes
• Evaluation of stripping based on subjective
evaluation of loss of asphalt binder coating
• Potential for quick field use or initial pass-fail test
• < 95% retained = problem
• Mixed results - no precision statement
24. 24HMA Characterization Moisture Sensitivity
Texas Freeze / Thaw Pedestal Test
• Subjects 41 mm diameter by 9.5 mm thick
sample to repeated freeze and thaw cycles
• Uses fine portion only
• One Cycle: 10o
F for 15 hr, 75o
F for 45 min.,
120o
F oven for 9 hr.
Repeat until sample cracks
< 10 cycles = moisture sensitive
> 20-25 cycles = resistant to moist.
25. 25HMA Characterization Moisture Sensitivity
HMA Voids
• Relationship between strength and air voids
Retained Mix Strength, %
Air Voids, %
0 5 10 15 20
100
0
Impermeable
Pessimum
Voids
Free Draining
26. 26HMA Characterization Moisture Sensitivity
Definitions
(Terrel and Swailmi, 1994)
• Impermeable or low void mixtures
• High asphalt binder or mastics
• Offset instability with crushing, large stone, and
modified AC
• Pessimum void range
• Conventional dense-graded HMA in US
• Free draining or open graded
• Modified asphalt binder and higher % for thicker films
• Remain open under traffic
The most obvious evidence of moisture sensitivity is the formation of potholes after a rainstorm. The new, unpatched pothole past the patched sections was deep enough to cause a number of vehicles to lose their hub caps. The owner of the nearby house had stacked hubcaps found in his front yard next to the mail box.
There are three general ways that the presence of moisture can damage HMA mixtures. The first is a function of asphalt binder-water interactions (loss of cohesion). Strength can also be lost as a result of the loss of bonding at the asphalt binder-aggregate interface. The third way water damages HMA is by the degradation of the aggregate because of less than desirable aggregate properties and/or severe environmental conditions.
Water droplets become dispersed in the asphalt binder film. This is referred to as an inverted emulsion; a typical emulsion is asphalt binder droplets suspended in a continuous water phase. This moisture sensitivity problem is amplified by the presence of emulsifiers. This could occur if an emulsion was used in the HMA mix). It may also occur if emulsifiers such as clays are present. The end result of a loss of cohesion is a loss of strength and stiffness of the HMA.
Overly wet stockpiles or damp stockpiles that are not thoroughly dried during production can cause problems. The moisture in the aggregate becomes trapped under the asphalt binder coating. Since aggregate tend to prefer water to asphalt binder, this can disrupt adhesion.
Hydraulic scour occurs when there is water in the pavement and traffic loads move the water back and forth over the coated surface. This happens as a result of the stress reversal from compression to tension when a load passes over a given point in the pavement.
In addition to hydraulic scour, traffic loads can actually force water into the asphalt binder film or through small pinholes in the film. This allows the water to displace the asphalt binder at the aggregate surface. It can also promote a loss of cohesion.
There are four major theories that cover the adhesion of the asphalt to the aggregate surface. The first one is purely mechanical. The next three listed on this slide are in some fashion governed by chemistry. Each of these theories will be discussed in more detail in the next few slides.
The mechanical theory of adhesion is a function of the characteristics of the aggregate surface. Smoother surface textured aggregates do not provide as good a “grip” by the asphalt binder to the surface of the aggregate. On the other hand, some researchers have reported that rougher textured aggregates may make it difficult to achieve a uniform (complete) coating of the aggregate, thereby allowing water to disrupt the asphalt binder film. The pore size and volume of pores (porosity) helps control the amount of asphalt absorbed as well as promoting selective absorption. In general, deeper penetration of the asphalt binder into the aggregate is considered to improve the mechanical interlock. It is thought that pore size may be more important than pore volume. A dirty surface (i.e., surfaces coated with clay-sized particles) prevents the asphalt binder from forming a good contact with the aggregate surface. Dust is thought to reduce the rate of spreading (coating) of the asphalt binder on the aggregate surface. It also prevents the penetration of the asphalt binder into the aggregate, thereby limiting the mechanical interlock. Greater aggregate surface areas or larger quantities of finer aggregates require greater amounts of asphalt binder. Appreciable amounts of fines (minus No. 200) require increasingly larger quantities of asphalt binder to completely coat all of the aggregate particles. The amount of asphalt binder needed for this coating is usually in excess of the amount selected during mix design. This leaves a less than desirable film thickness on the finer aggregates. Mixes with larger amounts of fines are generally considered to be more prone to stripping.
There is no firm agreement between researchers on the influence of combinations of asphalt binder-aggregate chemistries on moisture sensitivity. However, a number of researchers have indicated that stripping may be more of a problem with acidic aggregate mixes than with basic mixes.
This figure provides some general guidelines for what types of aggregates will have either positive or negative surface charges. According to this, the granites would tend to strip. However, there are some cases where these aggregate perform well. Similar exceptions can be found in practice with regards to limestone aggregates. Aggregates that are hydrophobic (don’t like water) tend to have a greater attraction for asphalt. In general, hydrophobia aggregates are basic and have low silica contents. Hydrophilic (water loving) aggregates are usually acidic and have a high silica content.
This slide provides some examples of how aggregate types would be ranked for stripping potential.
Weathered aggregate is considered less prone to stripping than freshly crushed aggregates. This is because the weathered aggregate surfaces have time to absorb oils from the atmosphere. These contaminates actually help the asphalt to coat the aggregate surface.
Wetting ability is defined as the ability of the asphalt binder to make a very close contact with the asphalt binder surface (Hicks, 1990). The resistance to flow (i.e., viscosity) is associated with molecular friction. Wetting ability is also related to surface tension which is the stress that tends to hold a drop of liquid in spherical shape.
There are two general types of antistripping additives used to reduce the moisture sensitivity of asphalt mixtures: liquid antistrips and lime. These will be discussed in more detail in the following slides.
These are surface-active agents that reduce the surface tension of the asphalt binder. A liquid antistripping additive is chosen so that the electrical charge is opposite to that of the aggregate. There are two methods by which liquid antistrips are added to the mix: mixed with the asphalt binder prior to mixing with aggregate, or added directly to the aggregate surface. While the last is conceptually the best for altering the chemistry at the asphalt binder-aggregate interface, the first is widely preferred for each and economical considerations. When the liquid is added to the asphalt binder, it is thought to migrate to the aggregate surface because of the differences in polarity at the interface. When the additive reaches the surface, is should displace any water molecules present, thus promoting adhesion. However, when the asphalt binder cools, the viscosity of the asphalt binder increases substantially. This tends to limit the ability of the liquid antistrip to migrate to the aggregate surface. The normal time available for migration is about 3 hours while the time needed for full migration has been estimated to be up to 12 hours.
Lime has been used since the early 1900’s, initially as a mineral filler. While there are two types of lime that can be used as an antistrip additive, the hydrated lime is preferred for safety reasons. Quickline produces a highly exothermic reaction in the presence of moisture. Hydrated lime reacts with most silicate aggregates to form a strongly-bonded crust of hydroxy silicate on the aggregate surface. This crust then attracts the carboxylic acids in the asphalt binder and strongly absorbs them onto the surface. Methods of application include: dry hydrated lime added to the cold feed belt, hydrated lime slurry mixed with the aggregate, dry hydrated lime mixed with water, and hot (quicklime) slurry. These are briefly discussed in the next two slides.
One of the major problems with the dry method is holding the lime on the surface of the aggregate until it is coated with asphalt binder. There tends to be more loss in drum plants which tend to pick up some of the lime in the gas flow. Also, the loose lime will act as a mineral filler in the asphalt binder rather than purely as an aggregate treatment. This method of adding lime has not proven to be as consistently effective as some of the other methods of addition. Hydrated lime, when mixed with water prior to use, is called a slurry. One of the main disadvantages to this method is that additional water is added to the aggregate stockpile and must be removed during drying. As an alternative, the aggregate can be treated with the lime slurry, then stockpiled (referred to as marinating) for up to 30 days. This allows time for the majority of the water to evaporate but requires that an additional aggregate handling process be added. One advantage is that it provides a good coating of the aggregate surface with much less lime lost to gas flow and filler.
Dry lime added to damp aggregate on the cold feed belt is probably one of the most common methods of adding lime. Mixing of the aggregate on the scalping screens and on belt changes helps coat the aggregate; the damp aggregate helps mitigate the loss of the lime. Quicklime costs about the same as hydrated lime. However, when it is mixed with water, the hydrated lime yield is about 25% greater. The exothermic reaction results in an increase in temperature which helps somewhat in removing the additional water.
This slide summarizes the main aggregate characteristics that are considered important by industry. Desirable characteristics are shown in parentheses.
There is no consensus within the HMA industry as to optimum asphalt properties. There is some evidence that higher viscosity asphalt binders tend to have less of a stripping potential. However, higher viscosity asphalt binders don’t coat the aggregate as well as a lower viscosity asphalt binder would. Asphalt binder with higher percentages of carboxylic acids and certain sodium compounds have been found to be more susceptible to moisture problems. Both low percentages of air voids and a dense gradation reduce the permeability of the mix. This limits the ability of the water to enter the mix, thereby improving its resistance to moisture damage.
If the weather is wet and cool during construction, the aggregate stockpiles tend to be overly damp and not thoroughly dried during HMA production. The cool weather can make it difficult to get the best in-place density. Both of these factors will increase the potential for moisture damage. The amount of rainfall and the number of freeze/thaw cycles the pavement is subjected to after construction can also have a significant affect on the ability of water to damage the pavement. Significant numbers of wet days increases the probability of problems with hydraulic scour or pore water pressure. These problems are accentuated with increasing traffic levels. A large number of freeze/thaw cycles tends to damage the pavement due to the expansion of the water when frozen.
The boiling water method is described in ASTM D3625. Originally, the sample was subjected to boiling water for one minute. However, several agencies did not feel that this was sufficient and increased the time to 10 minutes. Several researchers also indicated that after 10 minutes, the general effectiveness of any antistripping additives can be assessed. Once the samples have been in the boiling water, the loss of asphalt binder coating of the aggregate is evaluated. These subjective results are expressed in terms of the % coating retained. Because of the subjective nature of the this test, efforts to establish a precision statement have been unsuccessful. Most users recommend that this test method be limited to either an initial pass-fail evaluation or to process control during production.
A small sample 1-5/8 in in diameter by ¾ inches thick is prepared with a uniform sized aggregate then placed on a pedestal inside a container, covered with water, then subjected to repeated freeze/thaw cycles. The freeze/thaw cycles are continued until the sample cracks. If the sample cracks within the first 10 cycles, then the mix is considered to be moisture sensitive. More than 25 cycles, the mix is resistant to moisture damage. Disadvantages to this test are that only one aggregate fraction is considered in the assessment and the length of time needed to get a result (25 cycles needs 25 days).
Terrel and Swailmi proposed the concept of pessimum voids which indicates that the void system plays an important role in moisture resistance. Mixtures with low voids are relatively impermeable to water intrusion are as such not affected by the presence of water. Mixtures at some void content that is greater than about 14% because, although they are very permeable, they are also free-draining. That is, water does not stay in the material long enough to damage the material. In between these ranges, there is a critical range of voids which allows sufficient water intrusion but does not easily drain. This combination results in the greatest moisture damage. The range of voids associated with this region is referred to as the pessimum (as opposed to optimum) void range.
Typical mixes that fit these three void ranges are shown in this slide.