This document discusses research on modifying commercial siloxane stone protective compositions by adding silica nanoparticles to enhance stone protection. The key findings are:
- Adding silica nanoparticles to a siloxane protective composition and applying it to white Greek marble surfaces resulted in the formation of micron-sized protrusions made of nanoparticle aggregates. This altered the surface morphology and created a dual micro-nano roughness.
- This dual roughness strongly increased the hydrophobicity of the treated marble surfaces, rendering them super-hydrophobic (water contact angle over 150 degrees) at a silica nanoparticle concentration of 1% weight per volume.
- Other stone protection properties like water vapor permeability, water absorption, and effects on
This document summarizes a study that assessed the chemical, physical, and biological properties of new and field-conditioned cross-linked polyacrylamide gels. Both new gels and gels aged 1-6 years in fields contained low levels of acrylamide and acrylic acid monomers, except when subjected to elevated temperatures which caused higher monomer release. Gel water holding capacity decreased sharply within 18 months of field placement due to environmental conditions like UV exposure and freeze/thaw cycles. Microscopy revealed that gels became increasingly colonized by fungi and bacteria over time in fields. The study concluded that cross-linked polyacrylamide placed in soil is relatively stable but loses effectiveness due to declining water retention, raising questions
IRJET - Correlation of Chloride Solution Absorption-Time in Pre-Condition...IRJET Journal
This document summarizes a research study that investigated chloride absorption in pre-conditioned dry concrete cubes (DCC) with different mixture designs. Seventy-two 100mm concrete cubes were cast with six mixtures that varied compressive strength, water-cement ratio, and slump. Cubes were submerged in 10% NaCl solution for 160 days and weighed periodically to determine chloride absorption. Results showed chloride absorption increased over time and was lower in solvent-based and water-based impregnated cubes compared to control DCC cubes. Chloride absorption also decreased with increasing compressive strength and was correlated to time using logarithmic expressions for all cube types. The study aimed to characterize the influence of dry conditions and impregnation
IRJET- Dispersive Soils-Characterization, Problems and RemediesIRJET Journal
This document discusses dispersive soils, which are soils that easily disperse or break apart when exposed to flowing water. Dispersive soils can cause problems for earth structures and embankments. The document describes various tests that can identify dispersive soils, including the crumb test, double hydrometer test, and pinhole test. It also discusses how the mineralogy and chemistry of soils, particularly the presence of sodium ions, can cause soils to disperse. Remedies for stabilizing dispersive soils include adding amendments to change the soil chemistry.
IRJET- To Study Properties of Concrete by Replacing Fresh Water with Treated ...IRJET Journal
This document studies using treated waste water from various sources in concrete as an alternative to fresh water. It analyzes the chemical properties of different types of treated waste water and tests their impact on the properties and strength of cement and concrete. The results show that treated sewage waste water has little to no negative impact on concrete strength. In some cases, concrete made with treated sewage water showed improved strength over time compared to concrete made with fresh water. The study concludes that using treated waste water in concrete can conserve natural fresh water resources while not negatively affecting concrete quality.
Key Excerpts from Research Study Done on a Unique Ultrafine Cementitious GroutHess Pumice Products
Atomic Energy Canada LLC (AECL) was commissioned to optimize and verify the physical parameters of an ultrafine pozzolanic cementitious grout developed by Sandia National Laboratories for the U.S. Department of Energy. Key excerpts from that research report are reprinted in this slide deck.
A Critical Study of Water Loss in Canals and its Reduction MeasuresIJERA Editor
Water is a very precious natural resource. When this precious resource moves through the canals certain part of the water is lost by seepage, evaporation etc. This loss is known as conveyance loss. The conveyance loss was calculated experimentally by different researcher on different canals around the world. In this paper author have tried to review some of the research work and recommend an average water loss from the canal irrespective of the soil and other environmental condition. There are different materials which have been used in canal lining to reduce this water loss. No such material can be said it is the best material for reducing water loss because it depends on the site and its environmental condition. Now a days geosynthetic alone or geosynthetic with concrete or precast concrete is used to for canal lining in this paper they have tried to see the strength, durability etc. of different geosynthetic material and its application in canal lining.
The document summarizes an experimental study on the effect of salt water on the compressive strength of concrete. Concrete cubes were cast using both fresh water and salt water (35g of salts per liter of water), and cured for 7, 14, and 28 days. The compressive strength was then tested. The results showed that concrete cubes cast and cured with salt water had slightly higher compressive strengths compared to those cast and cured with fresh water at all ages. At 28 days, the compressive strengths were 39.12 MPa for fresh water cubes and 41.34 MPa for salt water cubes. The study concluded that there is no reduction and even a small increase in compressive strength when salt water is used for casting and
Forestland soil was the most permeable to water, allowing water to pass through in just a few minutes with 0% porosity. Clay soil was the least permeable, not allowing any water to pass through and having 100% porosity. Riverbank soil and beach soil had intermediate permeability, with riverbank soil having lower permeability than beach soil as indicated by the longer time for water to pass through. Porosity and permeability were found to be related, with soils having more pore space (higher porosity) exhibiting lower permeability.
This document summarizes a study that assessed the chemical, physical, and biological properties of new and field-conditioned cross-linked polyacrylamide gels. Both new gels and gels aged 1-6 years in fields contained low levels of acrylamide and acrylic acid monomers, except when subjected to elevated temperatures which caused higher monomer release. Gel water holding capacity decreased sharply within 18 months of field placement due to environmental conditions like UV exposure and freeze/thaw cycles. Microscopy revealed that gels became increasingly colonized by fungi and bacteria over time in fields. The study concluded that cross-linked polyacrylamide placed in soil is relatively stable but loses effectiveness due to declining water retention, raising questions
IRJET - Correlation of Chloride Solution Absorption-Time in Pre-Condition...IRJET Journal
This document summarizes a research study that investigated chloride absorption in pre-conditioned dry concrete cubes (DCC) with different mixture designs. Seventy-two 100mm concrete cubes were cast with six mixtures that varied compressive strength, water-cement ratio, and slump. Cubes were submerged in 10% NaCl solution for 160 days and weighed periodically to determine chloride absorption. Results showed chloride absorption increased over time and was lower in solvent-based and water-based impregnated cubes compared to control DCC cubes. Chloride absorption also decreased with increasing compressive strength and was correlated to time using logarithmic expressions for all cube types. The study aimed to characterize the influence of dry conditions and impregnation
IRJET- Dispersive Soils-Characterization, Problems and RemediesIRJET Journal
This document discusses dispersive soils, which are soils that easily disperse or break apart when exposed to flowing water. Dispersive soils can cause problems for earth structures and embankments. The document describes various tests that can identify dispersive soils, including the crumb test, double hydrometer test, and pinhole test. It also discusses how the mineralogy and chemistry of soils, particularly the presence of sodium ions, can cause soils to disperse. Remedies for stabilizing dispersive soils include adding amendments to change the soil chemistry.
IRJET- To Study Properties of Concrete by Replacing Fresh Water with Treated ...IRJET Journal
This document studies using treated waste water from various sources in concrete as an alternative to fresh water. It analyzes the chemical properties of different types of treated waste water and tests their impact on the properties and strength of cement and concrete. The results show that treated sewage waste water has little to no negative impact on concrete strength. In some cases, concrete made with treated sewage water showed improved strength over time compared to concrete made with fresh water. The study concludes that using treated waste water in concrete can conserve natural fresh water resources while not negatively affecting concrete quality.
Key Excerpts from Research Study Done on a Unique Ultrafine Cementitious GroutHess Pumice Products
Atomic Energy Canada LLC (AECL) was commissioned to optimize and verify the physical parameters of an ultrafine pozzolanic cementitious grout developed by Sandia National Laboratories for the U.S. Department of Energy. Key excerpts from that research report are reprinted in this slide deck.
A Critical Study of Water Loss in Canals and its Reduction MeasuresIJERA Editor
Water is a very precious natural resource. When this precious resource moves through the canals certain part of the water is lost by seepage, evaporation etc. This loss is known as conveyance loss. The conveyance loss was calculated experimentally by different researcher on different canals around the world. In this paper author have tried to review some of the research work and recommend an average water loss from the canal irrespective of the soil and other environmental condition. There are different materials which have been used in canal lining to reduce this water loss. No such material can be said it is the best material for reducing water loss because it depends on the site and its environmental condition. Now a days geosynthetic alone or geosynthetic with concrete or precast concrete is used to for canal lining in this paper they have tried to see the strength, durability etc. of different geosynthetic material and its application in canal lining.
The document summarizes an experimental study on the effect of salt water on the compressive strength of concrete. Concrete cubes were cast using both fresh water and salt water (35g of salts per liter of water), and cured for 7, 14, and 28 days. The compressive strength was then tested. The results showed that concrete cubes cast and cured with salt water had slightly higher compressive strengths compared to those cast and cured with fresh water at all ages. At 28 days, the compressive strengths were 39.12 MPa for fresh water cubes and 41.34 MPa for salt water cubes. The study concluded that there is no reduction and even a small increase in compressive strength when salt water is used for casting and
Forestland soil was the most permeable to water, allowing water to pass through in just a few minutes with 0% porosity. Clay soil was the least permeable, not allowing any water to pass through and having 100% porosity. Riverbank soil and beach soil had intermediate permeability, with riverbank soil having lower permeability than beach soil as indicated by the longer time for water to pass through. Porosity and permeability were found to be related, with soils having more pore space (higher porosity) exhibiting lower permeability.
IRJET - Shrinkage Crack Study due to Lead Contamination in Bentonite ClayIRJET Journal
1. The document studies the effect of lead contamination on the shrinkage cracking of bentonite clay. Bentonite clay samples contaminated with varying percentages of lead (0-0.1%) were tested.
2. The results showed that with increasing lead concentration, the consistency limits (liquid limit and plastic limit) of the bentonite clay decreased. The shrinkage limit was not significantly affected. Hydraulic conductivity increased with increasing lead concentration.
3. Digital image processing was used to analyze the crack patterns of the contaminated bentonite clay samples. The crack intensity factor, which is the ratio of crack surface area to total surface area, increased with higher lead contamination levels.
Study on Physical and Mechanical Properties of Dispersive Soilijtsrd
This paper deals with determination of physical and mechanical properties of dispersive soil. Soil is the foundation material which supports loads from the overlaying structure. Soil dispersivity is mainly due to the presence of exchangeable sodium present in the structure. Dispersive soils are identified by an unstable structure, easily flocculated in water, and very erodible. Using dispersive clay soils in hydraulic structures, embankment dams, or other structures such as roadway embankments can cause serious engineering problems if these soils are not identified and used appropriately. Some important parameters of dispersive soil obtained from laboratory testing are investigated in this paper. Soil sample is taken from Mandalay at about 3ft depth. To determine physical properties of soil, water content determination, specific gravity test, grain size analysis, Atterberg limits test, crumb test. Standard Proctor compaction test, Unconfined Compression Strength UCS test are carried out to determine mechanical properties of soil. According to Unified Soil Classification System, the studied soil is in CH group and group name is lean clay with sand. From crumb test, sample has grade 4. Therefore, the studied soil is highly dispersive. Soe Soe War | Nyein Nyein Thant "Study on Physical and Mechanical Properties of Dispersive Soil" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26627.pdfPaper URL: https://www.ijtsrd.com/engineering/civil-engineering/26627/study-on-physical-and-mechanical-properties-of-dispersive-soil/soe-soe-war
The viscosity of silica nanoparticle dispersions in permeable media UO
This document discusses a study on the viscosity of silica nanoparticle dispersions flowing through different types of permeable media, including glass bead packs, sandpacks, sandstone cores, and limestone cores. The researchers measured the viscosity of the dispersions in the porous media and compared it to viscosity measurements from a rheometer. They found that at high permeability media with regular pore structures, the concept of effective maximum packing fraction could be used to describe the viscosity. However, at low permeability media, mechanical trapping of nanoparticles affected the viscosity. The study provides new insight into modeling nanoparticle transport and rheology in subsurface applications.
This document discusses Atterberg limits, which are used to characterize the consistency of fine-grained soils based on water content. The limits include the plastic limit (PL), where soil starts to exhibit plastic behavior; the liquid limit (LL), where soil changes from liquid to plastic; and the plasticity index (PI), which is the difference between the LL and PL. The PI indicates the range of water contents where soil displays plastic properties, with higher PI soils tending to contain more clay. Atterberg limits are used internationally for soil identification and classification.
This document discusses soil consistency and the Atterberg limits test. It defines soil consistency as the ability to resist deformation based on moisture content. The Atterberg limits test determines the liquid limit (LL), plastic limit (PL), and plasticity index (PI) of a soil. The LL is the moisture content where a soil acts like a liquid. The PL is where it acts plastic. The PI is the range of moisture contents between plastic and liquid states. These values classify soil consistency and properties like compressibility.
This document presents the results of laboratory tests conducted to determine the Atterberg limits of a fine-grained soil, including the liquid limit, plastic limit, and plasticity index. The liquid limit test procedure and results are shown, indicating a liquid limit of 58%. The plastic limit test procedure and results show a plastic limit of 28%, giving a plasticity index of 30. Classification charts are included showing the plasticity characteristics of the soil. Procedures for determining the shrinkage limit are also presented.
Class 3 (a) Soil Plasticity (Atterberg Limits) ( Geotechenical Engineering )Hossam Shafiq I
This document discusses the Atterberg limits test procedure for classifying fine-grained soils. It defines the liquid limit as the moisture content at which a soil begins to behave as a liquid, and the plastic limit as the moisture content at which it begins to behave plastically. The plasticity index is the difference between the liquid and plastic limits. The document outlines how to determine these limits in the lab and use them to classify soils on a plasticity chart according to the Unified Soil Classification System.
IRJET- A Review on Effect of Various Additives on Dispersive Nature of Ex...IRJET Journal
This document discusses dispersive soils and various additives used to improve their properties. It begins with an abstract that defines dispersive soils as those containing high levels of sodium that break down into individual particles when wet, making them highly erodible. Various tests to identify dispersive soils are described. The document then reviews literature on characterizing dispersive soils and evaluating different additives like lime, gypsum, polymers to reduce their dispersivity. It discusses estimating the dispersivity of soils and different approaches to managing dispersive soils through chemical treatment or preventing erosion. Overall, the document provides an overview of dispersive soils and research on evaluating their properties and improving stability through the use of additives.
Class notes of Geotechnical Engineering course I used to teach at UET Lahore. Feel free to download the slide show.
Anyone looking to modify these files and use them for their own teaching purposes can contact me directly to get hold of editable version.
Maaf, saya tidak dapat menjawab soal latihan karena tidak ada informasi tentang hasil uji batas plastis dan shrinkage limit yang dibutuhkan untuk menghitung indeks-indeks seperti indeks plastisitas, aktivitas, dan sensitivitas. Saya hanya dapat menjelaskan definisi dan metode pengukuran batas Atterberg serta beberapa aplikasi tekniknya, tetapi tidak dapat menyelesaikan soal-soal latihan karena kurangnya data. Bisak
This document discusses the index properties of soil, which can be divided into soil grain properties and soil aggregate properties. Soil grain properties depend on individual grains and are independent of formation, including mineral composition, specific gravity, grain size and shape. Soil aggregate properties depend on the soil mass as a whole and represent collective behavior, influenced by stress history, formation and structure. Common index properties discussed include grain size distribution, Atterberg limits which classify soil consistency, and plasticity index. Engineering applications of index properties include soil classification, permeability estimation, and criteria for materials selection.
Effect of Resin on the Strength Characteristics of Thonnakkal ClayIJERA Editor
Improving the properties of soil by stabilization is considered as a means of fulfilling design criteria.
Stabilization is usually performed to improve material properties of soil such as strength, stiffness, and
permeability. The use of new materials for soil strengthening is crucial for geotechnical engineering, especially
in foundation construction. Experiments were conducted using resins with different epoxy resin-to-water
(ER/W) ratios. . The results show that by increasing the resin in the soil, the maximum dry density increases,
and the optimum water content decreases in the compaction tests.The results indicate that the epoxy resins
improve the physical and mechanical properties of soil significantly, and if successfully grouted into a
formation, the resins could provide a suitable solution for the stabilization of foundation material.
This document discusses soil consistency and various methods used to evaluate it, including rupture resistance, stickiness, plasticity, and Atterberg limits such as liquid limit, plastic limit and shrinkage limit. It describes how to determine these limits through standardized tests and defines relevant terms like plasticity index and liquidity index. The document also discusses factors that influence consistency like moisture content, clay mineralogy and activity. It provides classifications for terms like stickiness, plasticity and evaluates soil consistency through visual and tactile assessments.
The document discusses plasticity characteristics of soils including consistency limits defined by Atterberg. It defines liquid limit as the minimum water content where soil transitions from liquid to plastic state, plastic limit as the minimum content where it transitions from plastic to semi-solid, and shrinkage limit as the maximum water content where volume does not decrease with drying. It also discusses plasticity index, consistency index, liquidity index, sensitivity, thixotropy, and common clay minerals that contribute to plastic behavior in soils like montmorillonite, illite, and kaolinite.
This document discusses soil consistence and consistency, which are physical properties used to describe a soil's resistance to deformation under various stresses and moisture conditions. Consistence refers to resistance to rupture and is assessed by feel, while consistency refers to resistance to penetration. Categories of consistence include hard, friable, sticky, and plastic. Consistency is determined based on factors like plasticity, liquid limit, and plastic limit. Understanding consistence and consistency is important for soil classification, agricultural operations, and construction projects.
Swelling soils, also known as expansive soils,
are ones that swell in volume when subjected to
moisture. These swelling soils typically contain
clay minerals that attract and absorb water.
When water is introduced to expansive soils, the
water molecules are pulled into gaps between
the soil plates. As more water is absorbed, the
plates are forced further apart, leading to an
increase in soil pore pressure (Handy, 1995). If
this increased pressure exceeds surcharge
pressure (including the weight of the overlying
pavement) the soil will expand in volume to a
point where these pressures are once again in
balance. Swelling pressures can be on the order
of 100 – 200 kPa (14.5 – 29 psi) and have been
measured as high as 1000 kPa (145 psi). Table
1 gives a general idea of the types of expansion
that can be expected.
Compaction characteristics of fine grained soilavirup naskar
The document discusses compaction of soils. It defines compaction as artificially rearranging and packing soil particles into a closer state through mechanical means to decrease porosity and increase dry density. Compaction is done for purposes like increasing density, strength, load bearing capacity, and stability while decreasing compressibility, permeability, and erosion damage. It reviews literature on field permeability tests being more accurate than lab tests, correlating compaction characteristics like optimum moisture content with thermal behavior, and stabilizing compacted clay through admixtures or compactive effort. The conclusion discusses the importance of field tests, avoiding thin clay liners, compacting wet of optimum, relationships between density, moisture content and thermal properties, not rejecting high saturation tests,
The document describes procedures for determining the liquid limit and plastic limit of soil samples. The liquid limit test involves adding water to soil and determining the moisture content at which a groove closes after 25 blows. The plastic limit is the moisture content at which a soil ball crumbles after rolling out to 3mm diameter. These limits are used to classify soils and predict properties like strength and compressibility. The plasticity index, defined as the liquid limit minus the plastic limit, provides further information on soil type and reactivity. Proper determination of the Atterberg limits is important for building foundations to ensure suitable shear strength and volume change with moisture fluctuations.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Experimental Study on the Settling Velocity of
Coastal Mud in Quiescent Water: The Case of
Huangmaohai Estuary, South China Sea by Dong XU in Examines in Marine Biology and Oceanography: Open Access
IRJET - Shrinkage Crack Study due to Lead Contamination in Bentonite ClayIRJET Journal
1. The document studies the effect of lead contamination on the shrinkage cracking of bentonite clay. Bentonite clay samples contaminated with varying percentages of lead (0-0.1%) were tested.
2. The results showed that with increasing lead concentration, the consistency limits (liquid limit and plastic limit) of the bentonite clay decreased. The shrinkage limit was not significantly affected. Hydraulic conductivity increased with increasing lead concentration.
3. Digital image processing was used to analyze the crack patterns of the contaminated bentonite clay samples. The crack intensity factor, which is the ratio of crack surface area to total surface area, increased with higher lead contamination levels.
Study on Physical and Mechanical Properties of Dispersive Soilijtsrd
This paper deals with determination of physical and mechanical properties of dispersive soil. Soil is the foundation material which supports loads from the overlaying structure. Soil dispersivity is mainly due to the presence of exchangeable sodium present in the structure. Dispersive soils are identified by an unstable structure, easily flocculated in water, and very erodible. Using dispersive clay soils in hydraulic structures, embankment dams, or other structures such as roadway embankments can cause serious engineering problems if these soils are not identified and used appropriately. Some important parameters of dispersive soil obtained from laboratory testing are investigated in this paper. Soil sample is taken from Mandalay at about 3ft depth. To determine physical properties of soil, water content determination, specific gravity test, grain size analysis, Atterberg limits test, crumb test. Standard Proctor compaction test, Unconfined Compression Strength UCS test are carried out to determine mechanical properties of soil. According to Unified Soil Classification System, the studied soil is in CH group and group name is lean clay with sand. From crumb test, sample has grade 4. Therefore, the studied soil is highly dispersive. Soe Soe War | Nyein Nyein Thant "Study on Physical and Mechanical Properties of Dispersive Soil" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-5 , August 2019, URL: https://www.ijtsrd.com/papers/ijtsrd26627.pdfPaper URL: https://www.ijtsrd.com/engineering/civil-engineering/26627/study-on-physical-and-mechanical-properties-of-dispersive-soil/soe-soe-war
The viscosity of silica nanoparticle dispersions in permeable media UO
This document discusses a study on the viscosity of silica nanoparticle dispersions flowing through different types of permeable media, including glass bead packs, sandpacks, sandstone cores, and limestone cores. The researchers measured the viscosity of the dispersions in the porous media and compared it to viscosity measurements from a rheometer. They found that at high permeability media with regular pore structures, the concept of effective maximum packing fraction could be used to describe the viscosity. However, at low permeability media, mechanical trapping of nanoparticles affected the viscosity. The study provides new insight into modeling nanoparticle transport and rheology in subsurface applications.
This document discusses Atterberg limits, which are used to characterize the consistency of fine-grained soils based on water content. The limits include the plastic limit (PL), where soil starts to exhibit plastic behavior; the liquid limit (LL), where soil changes from liquid to plastic; and the plasticity index (PI), which is the difference between the LL and PL. The PI indicates the range of water contents where soil displays plastic properties, with higher PI soils tending to contain more clay. Atterberg limits are used internationally for soil identification and classification.
This document discusses soil consistency and the Atterberg limits test. It defines soil consistency as the ability to resist deformation based on moisture content. The Atterberg limits test determines the liquid limit (LL), plastic limit (PL), and plasticity index (PI) of a soil. The LL is the moisture content where a soil acts like a liquid. The PL is where it acts plastic. The PI is the range of moisture contents between plastic and liquid states. These values classify soil consistency and properties like compressibility.
This document presents the results of laboratory tests conducted to determine the Atterberg limits of a fine-grained soil, including the liquid limit, plastic limit, and plasticity index. The liquid limit test procedure and results are shown, indicating a liquid limit of 58%. The plastic limit test procedure and results show a plastic limit of 28%, giving a plasticity index of 30. Classification charts are included showing the plasticity characteristics of the soil. Procedures for determining the shrinkage limit are also presented.
Class 3 (a) Soil Plasticity (Atterberg Limits) ( Geotechenical Engineering )Hossam Shafiq I
This document discusses the Atterberg limits test procedure for classifying fine-grained soils. It defines the liquid limit as the moisture content at which a soil begins to behave as a liquid, and the plastic limit as the moisture content at which it begins to behave plastically. The plasticity index is the difference between the liquid and plastic limits. The document outlines how to determine these limits in the lab and use them to classify soils on a plasticity chart according to the Unified Soil Classification System.
IRJET- A Review on Effect of Various Additives on Dispersive Nature of Ex...IRJET Journal
This document discusses dispersive soils and various additives used to improve their properties. It begins with an abstract that defines dispersive soils as those containing high levels of sodium that break down into individual particles when wet, making them highly erodible. Various tests to identify dispersive soils are described. The document then reviews literature on characterizing dispersive soils and evaluating different additives like lime, gypsum, polymers to reduce their dispersivity. It discusses estimating the dispersivity of soils and different approaches to managing dispersive soils through chemical treatment or preventing erosion. Overall, the document provides an overview of dispersive soils and research on evaluating their properties and improving stability through the use of additives.
Class notes of Geotechnical Engineering course I used to teach at UET Lahore. Feel free to download the slide show.
Anyone looking to modify these files and use them for their own teaching purposes can contact me directly to get hold of editable version.
Maaf, saya tidak dapat menjawab soal latihan karena tidak ada informasi tentang hasil uji batas plastis dan shrinkage limit yang dibutuhkan untuk menghitung indeks-indeks seperti indeks plastisitas, aktivitas, dan sensitivitas. Saya hanya dapat menjelaskan definisi dan metode pengukuran batas Atterberg serta beberapa aplikasi tekniknya, tetapi tidak dapat menyelesaikan soal-soal latihan karena kurangnya data. Bisak
This document discusses the index properties of soil, which can be divided into soil grain properties and soil aggregate properties. Soil grain properties depend on individual grains and are independent of formation, including mineral composition, specific gravity, grain size and shape. Soil aggregate properties depend on the soil mass as a whole and represent collective behavior, influenced by stress history, formation and structure. Common index properties discussed include grain size distribution, Atterberg limits which classify soil consistency, and plasticity index. Engineering applications of index properties include soil classification, permeability estimation, and criteria for materials selection.
Effect of Resin on the Strength Characteristics of Thonnakkal ClayIJERA Editor
Improving the properties of soil by stabilization is considered as a means of fulfilling design criteria.
Stabilization is usually performed to improve material properties of soil such as strength, stiffness, and
permeability. The use of new materials for soil strengthening is crucial for geotechnical engineering, especially
in foundation construction. Experiments were conducted using resins with different epoxy resin-to-water
(ER/W) ratios. . The results show that by increasing the resin in the soil, the maximum dry density increases,
and the optimum water content decreases in the compaction tests.The results indicate that the epoxy resins
improve the physical and mechanical properties of soil significantly, and if successfully grouted into a
formation, the resins could provide a suitable solution for the stabilization of foundation material.
This document discusses soil consistency and various methods used to evaluate it, including rupture resistance, stickiness, plasticity, and Atterberg limits such as liquid limit, plastic limit and shrinkage limit. It describes how to determine these limits through standardized tests and defines relevant terms like plasticity index and liquidity index. The document also discusses factors that influence consistency like moisture content, clay mineralogy and activity. It provides classifications for terms like stickiness, plasticity and evaluates soil consistency through visual and tactile assessments.
The document discusses plasticity characteristics of soils including consistency limits defined by Atterberg. It defines liquid limit as the minimum water content where soil transitions from liquid to plastic state, plastic limit as the minimum content where it transitions from plastic to semi-solid, and shrinkage limit as the maximum water content where volume does not decrease with drying. It also discusses plasticity index, consistency index, liquidity index, sensitivity, thixotropy, and common clay minerals that contribute to plastic behavior in soils like montmorillonite, illite, and kaolinite.
This document discusses soil consistence and consistency, which are physical properties used to describe a soil's resistance to deformation under various stresses and moisture conditions. Consistence refers to resistance to rupture and is assessed by feel, while consistency refers to resistance to penetration. Categories of consistence include hard, friable, sticky, and plastic. Consistency is determined based on factors like plasticity, liquid limit, and plastic limit. Understanding consistence and consistency is important for soil classification, agricultural operations, and construction projects.
Swelling soils, also known as expansive soils,
are ones that swell in volume when subjected to
moisture. These swelling soils typically contain
clay minerals that attract and absorb water.
When water is introduced to expansive soils, the
water molecules are pulled into gaps between
the soil plates. As more water is absorbed, the
plates are forced further apart, leading to an
increase in soil pore pressure (Handy, 1995). If
this increased pressure exceeds surcharge
pressure (including the weight of the overlying
pavement) the soil will expand in volume to a
point where these pressures are once again in
balance. Swelling pressures can be on the order
of 100 – 200 kPa (14.5 – 29 psi) and have been
measured as high as 1000 kPa (145 psi). Table
1 gives a general idea of the types of expansion
that can be expected.
Compaction characteristics of fine grained soilavirup naskar
The document discusses compaction of soils. It defines compaction as artificially rearranging and packing soil particles into a closer state through mechanical means to decrease porosity and increase dry density. Compaction is done for purposes like increasing density, strength, load bearing capacity, and stability while decreasing compressibility, permeability, and erosion damage. It reviews literature on field permeability tests being more accurate than lab tests, correlating compaction characteristics like optimum moisture content with thermal behavior, and stabilizing compacted clay through admixtures or compactive effort. The conclusion discusses the importance of field tests, avoiding thin clay liners, compacting wet of optimum, relationships between density, moisture content and thermal properties, not rejecting high saturation tests,
The document describes procedures for determining the liquid limit and plastic limit of soil samples. The liquid limit test involves adding water to soil and determining the moisture content at which a groove closes after 25 blows. The plastic limit is the moisture content at which a soil ball crumbles after rolling out to 3mm diameter. These limits are used to classify soils and predict properties like strength and compressibility. The plasticity index, defined as the liquid limit minus the plastic limit, provides further information on soil type and reactivity. Proper determination of the Atterberg limits is important for building foundations to ensure suitable shear strength and volume change with moisture fluctuations.
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Experimental Study on the Settling Velocity of
Coastal Mud in Quiescent Water: The Case of
Huangmaohai Estuary, South China Sea by Dong XU in Examines in Marine Biology and Oceanography: Open Access
Resistance of Superhydrophobic Surface-Functionalized TiO2 Nanotubes to Corro...Pawan Kumar
The availability of robust superhydrophobic materials with the ability to withstand harsh environments are in high demand for many applications. In this study, we have presented a simple method to fabricate superhydrophobic materials from TiO 2 nanotube arrays (TNTAs) and investigated the resilience of the materials when they are subjected to harsh conditions such as intense cavitation upon ultrasonication, corrosion in saline water, water-jet impact, and abrasion. The TNTAs were prepared by anodization of Ti foil in buffered aqueous electrolyte containing fluoride ions. The hydrophilic TNTAs were functionalized with octadecylphosphonic acid (ODPA) or 1H, 1H′, 2H, 2H′-perfluorodecyl phosphonic acid (PFDPA) to form a self-assembled monolayer on the TNTA surface to produce superhydrophobic [email protected] or [email protected] surfaces. The superhydrophobic [email protected] and [email protected] have contact angles of 156.0±1.5 and 168±1.5, and contact angle hysteresis of 3.0 and 0.8, respectively. The superhydrophobic [email protected] and [email protected] were subjected to ultrasonication, corrosion in saline water, and water-jet impact and abrasion, and the resilience of the systems was characterized by electrochemical impedance spectroscopy (EIS), contact angle (CA) measurements, diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS), and field-emission scanning electron microscopy (FESEM). The results presented here show that superhydrophobic [email protected] and [email protected] are robust and resilient under the harsh conditions studied in this work, and indicate the potential of these materials …
The availability of robust superhydrophobic materials with the ability to withstand harsh environments are in high demand for many applications. In this study, we have presented a simple method to fabricate superhydrophobic materials from TiO2 nanotube arrays (TNTAs) and
investigated the resilience of the materials when they are subjected to harsh conditions such as
intense cavitation upon ultrasonication, corrosion in saline water, water-jet impact, and abrasion. The TNTAs were prepared by anodization of Ti foil in buffered aqueous electrolyte containing fluoride ions. The hydrophilic TNTAs were functionalized with octadecylphosphonic acid (ODPA) or
1H, 1H0, 2H, 2H0-perfluorodecyl phosphonic acid (PFDPA) to form a self-assembled monolayer
on the TNTA surface to produce superhydrophobic ODPA@TNTA or PFDPA@TNTA surfaces.
The superhydrophobic ODPA@TNTA and PFDPA@TNTA have contact angles of 156.0+-1.5 and 168+- 1.5, and contact angle hysteresis of 3.0 and 0.8, respectively. The superhydrophobic
ODPA@TNTA and PFDPA@TNTA were subjected to ultrasonication, corrosion in saline water, and water-jet impact and abrasion, and the resilience of the systems was characterized by electrochemical impedance spectroscopy (EIS), contact angle (CA) measurements, diffuse reflectance
Fourier transform infrared spectroscopy (DRIFTS), and field-emission scanning electron microscopy (FESEM). The results presented here show that superhydrophobic ODPA@TNTA and PFDPA@TNTA are robust and resilient under the harsh conditions studied in this work, and indicate the potential of
these materials to be deployed in practical applications.
The viscosity of silica nanoparticle dispersions in permeable media UO
This document discusses a study on the viscosity of silica nanoparticle dispersions flowing through different types of permeable media, including glass bead packs, sandpacks, sandstone cores, and limestone cores. The researchers measured the viscosity of the dispersions in the porous media and compared it to viscosity measurements from a rheometer. They found that at high permeability media with regular pore structures, the concept of effective maximum packing fraction could be used to describe the viscosity. However, at low permeability media, mechanical trapping of nanoparticles affected the viscosity. The study provides new insight into modeling nanoparticle transport and rheology in subsurface applications.
Threshold hydrophobicity for inhibition of salt scale formation on SAMmodifie...Pawan Kumar
Fouling of solid surfaces is a ubiquitous problem in industrial processes. As unwanted material accumulates on
components, their function is impaired and costly repairs are required. Most fouling occurs from impurities
present in water that are deposited when the water contacts a solid surface. It follows that if the adhesive forces
at the water-solid interface are minimized, less fouling will result. In this study, we present a novel method to
minimize fouling by fabricating a hydrophobic surface based upon self-assembled monolayer (SAM)-modified
titanium dioxide nanotube arrays (TNTAs). We demonstrate a direct correlation between hydrophobicity and the
formation of scale from dissolved salts by comparison of the surface’s static contact angle and degree of precipitation deposition. Furthermore, by tailoring the surface hydrophobicity through employment of a wide
variety of SAMs with different alkyl chain lengths, we determine the threshold level of hydrophobicity that
inhibits fouling in the SAM-TNTA system; surfaces with a static contact angle greater than 144° display vastly
increased fouling resistance. The surface morphology, surface composition, and stability of the alkyl phosphonic
acid- and perfluoroalkyl phosphonic acid-SAM-TNTAs were characterized using scanning electron microscopy
(SEM), energy-dispersive X-ray spectroscopy (EDX), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS).
Threshold hydrophobicity for inhibition of salt scale formation on SAM-modifi...Pawan Kumar
Fouling of solid surfaces is a ubiquitous problem in industrial processes. As unwanted material accumulates on components, their function is impaired and costly repairs are required. Most fouling occurs from impurities present in water that are deposited when the water contacts a solid surface. It follows that if the adhesive forces at the water-solid interface are minimized, less fouling will result. In this study, we present a novel method to minimize fouling by fabricating a hydrophobic surface based upon self-assembled monolayer (SAM)-modified titanium dioxide nanotube arrays (TNTAs). We demonstrate a direct correlation between hydrophobicity and the formation of scale from dissolved salts by comparison of the surface’s static contact angle and degree of precipitation deposition. Furthermore, by tailoring the surface hydrophobicity through employment of a wide variety of SAMs with different alkyl chain lengths …
The document describes a study that investigated using freezing as a method for desalinating seawater. Three seawater samples were collected from Boshehr beach in the Persian Gulf and subjected to three cycles of a freezing-melting process. This involved crystallization at -20°C, separation of ice crystals, surface washing, and melting. Testing showed that after three cycles, the total dissolved solids in the samples were reduced to levels making the water potable. Freezing is a potential desalination method for remote areas due to its low energy requirements compared to other processes like reverse osmosis. However, freezing also has disadvantages such as higher costs and potential water quality issues.
This study investigated the effect of water-cement ratio, cement type, and seawater exposure on the electrical resistivity of concrete. Specimens were made with Type I and Type IP cement and water-cement ratios of 0.50, 0.55, 0.60 and 0.65. Some specimens were submerged in seawater for 60 days while others were submerged in a 3% NaCl solution to simulate seawater exposure conditions. Testing found that electrical resistivity decreased as the water-cement ratio increased and that Type IP cement concrete had higher resistivity than Type I cement concrete. It was concluded that lower water-cement ratios and Type IP cement yielded the highest electrical resistivity when
This document summarizes research on developing environmentally friendly marine antifouling coatings using silicone-based nanocomposites containing spherical silver nanoparticles. The researchers fabricated polydimethylsiloxane/silver nanocomposite models with varying concentrations of spherical silver nanoparticles less than 10 nm in size via solution casting. They characterized the surface properties and mechanical properties and tested the antifouling performance against bacteria over 30 days and in field trials in sea water for 12 months. The results showed that nanocomposite models with up to 0.1% silver nanoparticles improved hydrophobicity, surface inertness, fouling resistance, and easy cleaning without affecting mechanical properties, demonstrating their potential as effective and eco-friendly antifouling coatings.
This document analyzes the effects of alkaline and acid solutions on the mechanical properties of glass/epoxy composites. It finds that:
1) Immersion in hydrochloric acid (HCl) and sodium hydroxide (NaOH) solutions decreases the flexural strength and modulus of the composites over time.
2) The alkaline sodium hydroxide solution promotes a higher decrease in flexural properties than the acid hydrochloric solution.
3) Both solutions also decrease the impact strength of the composites with increased exposure time, with the alkaline solution again having a greater effect.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Polyethersulfone (PES) is a polymeric permeable material used in ultrafiltration (UF)
membranes due to its high thermomechanical and chemical stability. The hydrophobic nature of
PES membranes renders them prone to fouling and restricts the practical applications of PES in the
fabrication of water treatment membranes. The present study demonstrates a non-solvent-induced
phase separation (NIPS) approach to modifying PES membranes with different concentrations of
discrete TiO2 nanotubes (TNTs). Zeta potential and contact angle measurements showed enhanced
hydrophilicity and surface negative charge in TNTs/PES nanocomposite membranes compared to
unmodified PES membranes. To discern the antifouling and permeation properties of the TNTs/PES
membranes, steam assisted gravity drainage (SAGD) wastewater obtained from the Athabasca oil
sands of Alberta was used. The TiO2 modified polymer nanocomposite membranes resulted in a
higher organic matter rejection and water flux than the unmodified PES membrane. The addition of
discrete TNTs at 1 wt% afforded maximum water flux (82 L/m2 h at 40 psi), organic matter rejection
(53.9%), and antifouling properties (29% improvement in comparison to pristine PES membrane).
An enhancement in fouling resistance of TNTs/PES nanocomposite membranes was observed in
flux recovery ratio experiments.
Polyethersulfone (PES) is a polymeric permeable material used in ultrafiltration (UF) membranes due to its high thermomechanical and chemical stability. The hydrophobic nature of PES membranes renders them prone to fouling and restricts the practical applications of PES in the fabrication of water treatment membranes. The present study demonstrates a non-solvent-induced phase separation (NIPS) approach to modifying PES membranes with different concentrations of discrete TiO 2 nanotubes (TNTs). Zeta potential and contact angle measurements showed enhanced hydrophilicity and surface negative charge in TNTs/PES nanocomposite membranes compared to unmodified PES membranes. To discern the antifouling and permeation properties of the TNTs/PES membranes, steam assisted gravity drainage (SAGD) wastewater obtained from the Athabasca oil sands of Alberta was used. The TiO 2 modified polymer nanocomposite membranes resulted in a higher organic matter rejection and water flux than the unmodified PES membrane. The addition of discrete TNTs at 1 wt% afforded maximum water flux (82 L/m 2 h at 40 psi), organic matter rejection (53.9%), and antifouling properties (29% improvement in comparison to pristine PES membrane). An enhancement in fouling resistance of TNTs/PES nanocomposite membranes was observed in flux recovery ratio experiments. View Full-Text
This document describes a study on incorporating discrete titanium dioxide (TiO2) nanotubes into polyethersulfone (PES) membranes using a non-solvent induced phase separation approach to modify the membranes. Different concentrations of TiO2 nanotubes were added to create nanocomposite membranes. Characterization showed the nanocomposite membranes had enhanced hydrophilicity and negative surface charge compared to unmodified PES membranes. Testing also found the TiO2 nanotube modified membranes had higher water flux, better organic matter rejection, and improved antifouling properties when filtering real wastewater compared to the unmodified PES membrane. Adding 1 wt% TiO2 nanotubes provided the best performance.
Study of the effect of Illite and Kaolinite on low salinity water injectionIJERA Editor
Low salinity water flooding as an Enhanced Oil Recovery (EOR) Technique refers to the injection of brine with a lower salt content or ionic strength into an oil reservoir. Although the mechanisms have not yet been verified, the solution and surface chemistry as well as rock/fluid interactions have important roles that can be attributed to reservoir minerals being sensitive to small changes in solution properties. Among the proposed mechanisms, the clay content of rock and type of clay has been of significant interest in shedding light on the low salinity water flooding process. In this paper, two clay types (illite and kaolinite) have been selected to investigate the individual contribution of each on the rock surface characterization andlow salinity water flooding performance.
The results from contact angle measurement on the oil-wet calcite by low salinity water at room temperature show that the presence of low content of illite in the rock materials, in contrast to the kaolinite, reduces the contact angle significantly. This observation demonstrates that the low salinity water flooding performance depends strongly on the type of clay not on the amount of clay.
Characterization and Humidity Sensing Application of WO3-SnO2 NanocompositeIOSR Journals
The document summarizes a study characterizing the humidity sensing properties of tungsten oxide (WO3) doped with tin oxide (SnO2) nanocomposites. WO3-SnO2 nanocomposites were prepared by solid-state reaction and analyzed for their electrical resistance changes with varying humidity levels. The 3% SnO2-doped WO3 sample annealed at 600°C showed the highest average sensitivity of 18.61 MΩ/%RH over a humidity range of 15-95% RH, along with lower hysteresis, less aging effects, and high reproducibility. X-ray diffraction analysis revealed the crystallite size of the sensing elements to be in the range of 11-234 nm
This document summarizes research on using physical water treatment (PWT) devices to prevent mineral fouling in cooling tower applications. It describes three PWT devices tested - permanent magnets, a solenoid coil device, and a high-voltage electrode. The proposed mechanism of PWT is bulk precipitation of mineral ions in solution rather than deposition on surfaces, potentially producing softer particulate fouling. Experiments evaluated the effects of flow velocity and magnetic/electric field configurations on PWT effectiveness. Results from heat transfer tests and scale analysis provided evidence that PWT can significantly reduce fouling compared to untreated water when devices are optimized.
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Using recycled concrete aggregates (RCA) for pavements is crucial to achieving sustainability. Implementing RCA for new pavement can minimize carbon footprint, conserve natural resources, reduce harmful emissions, and lower life cycle costs. Compared to natural aggregate (NA), RCA pavement has fewer comprehensive studies and sustainability assessments.
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapte...University of Maribor
Slides from talk presenting:
Aleš Zamuda: Presentation of IEEE Slovenia CIS (Computational Intelligence Society) Chapter and Networking.
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Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
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2. The application resulted in super-hydrophobic treated marble sur-
faces. This is attributed to the presence of nanoparticles, which affect
the surface morphology. The surface morphology was examined by
SEM and AFM. In addition, water vapor permeability, water capillary
absorption and stone color alterations were measured and their
dependence on the nanoparticle concentration was established. These
measured quantities are additional parameters necessary to be con-
sidered for the optimal protection of stone and stone-based monuments.
2. Experimental
Three types of white Greek marbles were used as substrates: Pentelic
marble (98% calcite, 2% quartz, open porosity 0,21%), Naxos marble (98%
calcite, 2% quartz, openporosity 0,12%) and while marble of Thassos (86%
dolomite, 12% calcite, 2% quartz, open porosity 0,20%). The marble
specimens were squared blocks of around 2.5×2.5×1 cm cut from one
marble plate acquired from domestic marble supplier. Before treatment
the marbles were washed with deionized water and acetone. The surface
of the specimens was not abraded. The root-mean-square (rq) surface
roughness of the acquired marble specimens was measured by AFM at
20×20 μm scan areas and was found to be 1±0.1 μm for Pentelic marble,
1.2±0.1 μm for Naxos marble and 0.9±0.1 μm for Thassos marble.
Hydrophilic white-colored silica nanoparticles (Silica, fumed
powder, Aldrich) with 7 nm mean diameter were mixed with 7% w/v
polyalkysiloxane solution in white spirit (Rhodorsil Hydrof, Rhodia
Silicones, Italy). Different percentages of SiO2 nanoparticles (0, 0.1, 0.3,
0.5, 1, 1.5, 2% w/v) were used for mixing with the above polymeric
material. The mixtures were stirred vigorously for 20 min in order a
homogeneous dispersion to be prepared. The as-prepared polymer–
particle mixtures were sprayed onto three samples of the same type of
marble through a nozzle of 733 μm using an airbrush system (Paasche
airbrush). The quantity of the spraying mixture was kept steady by
controlling the spray pressure (2.5 bars) and the optimal spray time
(2 s) selected on the basis of preliminary experiments. Preliminary
experiments showed that spray times N5 s result in poorly adhered
films. The treated specimens were subsequently annealed at 40 °C and
low vacuum (0.5 bars) overnight and then kept at room temperature
for 2 to 3 days until constant weight (±0.001 g). After the evaporation
of the solvent, investigation of the surface properties and evaluation of
stone protection efficiency were carried out. The results presented in
this work are the average of the results obtained on three different
samples of the same type of marble.
The effect of nano-silica was compared to that of micro-silica.
Hydrophilic white-colored silica microparticles (Silicon dioxide,
Sigma) with particle size 0.5–10 μm (~80% between 1 and 5 μm)
were mixed (1% and 2% w/v) with Rhodorsil and the composition was
applied on Pentelic marble in a previously described manner.
Water contact angle measurements were conducted using distilled
water and a Krüss DSA 100 contact angle measuring instrument. Five
droplets of water were delivered to different points of each specimen
and from a height sufficiently close to the substrate, so that the needle
remained in contact with the water droplet. Then, the delivery needle
was withdrawn with minimal perturbation to the drop [16]. The
volume of each droplet was 5–8 μl. The contact angle hysteresis was
calculated by the dynamic sessile drop method. The advancing/
receding contact angle (θa/θr) was the maximum/minimum angle
measured, while the volume of the droplet was increased/decreased
without increasing/decreasing the solid–liquid interfacial area. The
reported contact angle values are averages of five measurements.
Water contact angle hysteresis is defined as the difference between
advancing and receding contact angle.
For the vapor permeability, sample blocks were fixed on the top of
identical cylindrical PVC containers that were partially (1/2) filled
with water. Then, the containers properly sealed with stone lids were
placed in a climatic chamber, kept at R.H. 25% and at constant
temperature of 40±0.5 °C. The containers were weighted every 24 h. It
was assumed that the vapor flow through the stone had reached a
constant value when the difference between two consecutive daily
(24 h) weight variations, ΔMi–1 and ΔMi, was less than 5% [4,17]:
ΔMi−ΔMi–1
ΔMi
×100b5k ð1Þ
Under constant vapor flow the water vapor permeability was
evaluated as the mass of water vapor passing though the surface unit
(cm2
) in 24 h. Three consequent measurements with the interval of
24 h were made and the average value was used.
Capillary water absorption measurements were performed by the
gravimetric sorption technique [3]. The dried weighted stone block
was placed with the treated side on a filter paper pad (1 cm of
Whatman paper, No 4) partially immersed in distilled water. After 1 h
of experiment, the sample was extracted and after removing the water
drops with a wet cloth, it was weighted again to determine the
amount of water absorbed by capillary forces.
The effect of the polymer–particle mixtures on the optical
appearance of the marbles was evaluated with colorimetric measure-
ments. The same five homogeneous spot areas of 4 mm in diameter, of
each specimen were examined, before and after treatment. For this
purpose a portable reflectance spectrophotometer MiniScan®
XE Plus
(HunterLab Associates Inc, USA) was used. The results were evaluated
by the use of L⁎a⁎b⁎ coordinates of the CIE 1976 scale [18,19].
The morphologies of the surfaces were investigated by scanning
electron microscopy (SEM, Jeol-5900LV) and by atomic force micro-
scopy (AFM, Multimode IIId, Veeco Inc.) operated in tapping mode.
The dimensions of the surface structures were measured with NIH
software (National Institutes of Health, U.S.A.).
3. Results and discussion
3.1. Surface morphology
The morphology of the treated marble surfaces depends on the
nanoparticle concentration in the siloxane protective composition, as
it can be seen from the SEM images (Fig. 1). Without nanoparticles a
continuous siloxane film was formed (Fig. 1a), which followed the
marble block surface morphology and assured water contact angle of
110°. The addition of nanoparticles led to the formation of separated
protrusions on the treated surface (Fig. 1b–d). The size and the surface
density of the protrusions were proportional to nanoparticles
concentration. In particular, the marble's surface area covered by the
protrusions increased from 10% (0.1% w/v silica) to more than 50% (2%
w/v silica). These observations testify that nanoparticles are not
homogeneously dispersed in the polymer film, but they form
aggregates with average diameters dependent on the nanoparticles
concentration and ranging from 10 μm (0.1% w/v silica) to 100 μm (2%
w/v silica). The diameters of the aggregates were estimated from SEM
images using ImageJ NIH software. The aggregates have irregular
shape (Fig. 1e) with highly developed nanostructure, as it can be seen
from the AFM images of the aggregate's surfaces (Fig. 2). Fig. 2a shows
the surface morphology of a 5×5 μm scan area. The nano-scale
roughness is clearly observed in Fig. 2b, where the scan area is only
1×1 μm and the roughness (rq) is 44.9 nm.
Therefore, the addition of nanoparticles to the siloxane composi-
tion resulted in the formation of the superficial micro protrusions and
overall alteration of surface morphology and roughness. The dimen-
sions of the protrusions (μm-scale) and the developed nanostructure
(nm-scale) led to the development of a two-length scale, micro- and
nano-roughness on the surface of treated marbles. As it is well-known,
a two-scaled surface roughness strongly amplifies surface hydro-
phobicity [20]. Thus, roughness at nano- and micron-scale has been
considered responsible for the development of super-hydrophobic
and self-cleaning properties on the Lotus leaf (“lotus effect”) and on
1323
P.N. Manoudis et al. / Surface & Coatings Technology 203 (2009) 1322–1328
3. other natural materials. The Lotus leaf is covered by many papillae
with their diameters in the range of 3–10 μm, while these papillae are
covered with smaller protrusions in the nano-scale [21,22]. Water
droplets are present on it with a nearly spherical shape and can roll off
easily with a slight vibration.
3.2. Water contact angle
The marbles are hydrophilic materials. The static water contact angle
(SCA) on the untreated marbles was 40–50°. Hydrophobization of
marble surface with unmodified siloxane composition (Rhodorsil
Hydrof) increases the SCA up to 110°. The addition of silica nanoparticles
further increases the hydrophobicity of the surface and for particle
concentrations N1% w/v, it renders the surface super-hydrophobic
(SCA N150°, Fig. 3). Maximum hydrophobicity (SCA ~160°) for all
marbles treated is achieved at 1% w/v of silica and further increase in
nanoparticles concentration does not enhance the surface hydrophobi-
city any more (Fig. 3). It is important to note that for concentrations
lower than 1% w/v, where the aggregates cover only relatively small
part of the substrate surface (Fig.1b), the observed water contact angle
depends on the marble nature (Fig. 3). For particle concentration
higher than 1% w/v, the water contact angle is independent of the
substrate. Obviously, at these concentrations, the surface density of
silica-siloxane aggregates is sufficient to abrogate the water contact
with the substrate. As it was calculated from the SEM images, at the 2%
w/v concentration the silica-siloxane aggregates cover more than 50%
of the substrate surface (Fig.1d). Interestingly, the application of 2% w/v
modified composition on other substrates assured the same level of
their hydrophobization (SCA=162°±0.5°) independently of the sub-
strate nature (glass, Si wafer, silk fabric, plywood, aluminium) [15]. The
observed similarities in hydrophobic behavior of different substrates
treated with 2% w/v modified composition are the consequences of the
same physical reason and the result of the formation of a superficial
silica-siloxane protective layer that eliminates the water droplet
contact with the substrate. This can be the consequence of the
heterogeneous wetting regime in which a water droplet sits on a
mixture of trapped air and solid silica-siloxane protrusions (Cassie-
Baxter regime [23]).
Fig. 1. SEM images of the Pentelic marble surface treated with Rhodorsil and (a) 0%, (b) 0.1%, (c) 1%, (d) 2% w/v silica nanoparticles and (e) of a single protrusion formed on the marble
treated with Rhodorsil and 2% w/v silica.
1324 P.N. Manoudis et al. / Surface & Coatings Technology 203 (2009) 1322–1328
4. It should be underlined that the nano-dimensions of silica particles
are important for the superhydrophobization of the marble surface. In
the case of silica particles with micro-dimensions, the superhydro-
phobic effect was not achieved and substantially lower contact angles
were observed. Thus, in the case of Rhodorsil modified by silica
microparticles (mean diameter 3μm) and then applied on Pentelic
marble, the observed SCAwas 120.5±5° and 132±4° for 1 and 2% w/v of
silica, correspondingly. These values are substantially lower than those
observed in the case of Rhodorsil modified by the same concentrations
of silica nanoparticles: 161.3±1° and 162±1.5° for 1% and 2% w/v of
nanosilica, correspondingly. Apparently, the nano-dimensions of silica
particles are essential for the formation of the developed nano-
topography/nano-roughness of the protective layer. As we mentioned
previously, a two-length-scale, micro- and nano-hierarchical surface
roughness is important to achieve super-hydrophobicity.
Super hydrophobic, highly water repellent properties of the
treated marble surfaces were as well confirmed by the investigation
of water contact angle hysteresis, which is more adequate for the
indication of hydrophobicity [24,25]. A highly water repellent surface
is characterized by low water contact angle hysteresis and thus, a
water droplet can move with little applied force and roll off easily. In
our case, at elevated silica concentrations (N1%w/v), the advancing
and receding contact angles were higher than 150° and consequently,
the water contact angle hysteresis was low. In particular, in the case of
Pentelic marble treated with 1% w/v modified composition the
hysteresis was 7° (θa/θr: 162°/155°). For 2% w/v particles, the
hysteresis was reduced to 5° (θa/θr: 164°/159°). As a consequence, a
water droplet easily rolls off from the surface, as it can be seen from
consecutive images (1–16, Fig. 4) of a water droplet on the treated
Pentelic marble surface. The water droplet was left from the needle
and after bouncing on the surface, it finally rolls off.
3.3. Water capillary absorption
It should be mentioned that even in the case of hydrophobic
surfaces the water can invade the stone by capillary absorption and
that protection against such invasion is part of the overall stone
protection strategy [3]. Previous works have demonstrated that the
water absorption is very rapid and most of the amount of the water is
absorbed within the first 20 min [3,26]. Therefore, the water capillary
absorption experiment time was set to be 1 h. The reduction of water
capillary absorption (RCA) is defined as:
RCA =
mu−mt
mu
×100 ð2Þ
mu: the mass of the water absorbed by the untreated substrate
mt: the mass of the water absorbed by the treated substrate.
An ideal protective coating should eliminate water absorption by
capillarity. The water absorption by capillarity of the untreated marbles
was 3–5 mg/cm2
h. When pure polymer was sprayed on the marbles,
the water absorption reduced by 69.4±1.4–75.4±1.5% (Fig. 5). At low
particle contents, from 0 to 1% w/v, a gradual decrease in the reduction
of water capillary absorption is observed. The minimum reduction of
the water capillary absorption was 40±2% in the case of 1% w/v particle
concentration on the marble of Thassos. In this range of particle
concentration (0.1–1% w/v), the aggregates formed are sparsely
dispersed on the surface of the marbles (Fig. 1) covering less than
25% of the total surface area. At the same time, a part of the siloxane
polymer is obviously consumed for the silica-siloxane aggregates
consolidation. As a result, the polymer film in-between aggregates
becomes thinner or even disrupted and this fact leads to the decrease in
the efficiency of stone protection from water capillary absorption.
At elevated particle concentration (N1% w/v), the coverage of the
stone surface by the hydrophobic aggregates is significantly higher,
Fig. 3. Water contact angle vs. concentration of silica nanoparticles. Photograph of water
droplets on Pentelic marble treated with 2% w/v silica nanoparticles is included.
Fig. 2. AFM images (a) scan area 5×5 μm (b) scan area 1×1 μm, on the surface of the protrusions formed on the Pentelic marble surface treated with Rhodorsil and 1% w/v SiO2. At the
upper side of each image the root-mean-square roughness (rq) is presented.
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P.N. Manoudis et al. / Surface & Coatings Technology 203 (2009) 1322–1328
5. reaching a maximum of about 50% at 2% w/v (Fig. 1d). So a dense
superficial, highly hydrophobic silica-siloxane composition layer is
formed on the surface of the marbles. This results in the decrease of
water capillary absorption up to 89.5±0.7–96±1% (Fig. 5). The
achieved reduction was substantially better than that achieved by
the application of the non-modified siloxane composition.
The results obtained also demonstrate that the development of
super-hydrophobicity on the stone surface does not necessarily assure
optimal stone protection against water invasion. For example, in the
case of polymer–particle composite films with 0.5–1% w/v particle
content, the marbles are super hydrophobic, while the reduction of
water capillary absorption is lower compared to the reduction
obtained when pure polymer is applied on the marbles.
Under real outdoor conditions, stones can be exposed to
condensed water for longer than 1 h, time usually used in experiments
for the estimation of water capillary absorption. For this reason, we
also investigated the reduction in water absorption by capillary for
24 h exposure of the treated Pentelic marble samples. For this
prolonged exposure the reduction in water capillary absorption by
pure siloxane film was only 20±1%, while by the application of 2% w/v
silica-siloxane composition the reduction was substantially higher
and reached 50±2%. These data once again demonstrate the enhanced
efficiency of silica-siloxane composition for stone protection.
3.4. Water vapor permeability
The water vapor transmission rates through the stone should not
be reduced after treatment, assuring the proper vapor regime inside
the stone and the building. The impermeability of the stone protective
coating to water vapor can lead to water condensation just under-
neath the protective layer and to subsequent stone decay by the above
described condensed-water action. The reduction of water vapor
permeability is inevitable, since it is an immediate consequence of the
water repellence properties of the protective layer. However, the
lowest possible decrease is pursued. The reduction of water vapor
permeability is defined as:
RVP =
mu−mt
mu
×100 ð3Þ
mu: the mass of the vapor which penetrates the untreated substrate
mt: the mass of the vapor which penetrates the treated substrate.
The vapor permeability through the untreated marbles was 0.11–
0.14 g/cm2
d. When pure polymer was applied to marbles, the
reduction of the vapor permeability was 10±1%–12±1% depending
on the substrate (Fig. 6). The addition of silica nanoparticles to the
composition further reduces the vapor permeability with maximum
reduction of 40.3±0.5% at 2% w/v of nanoparticles. It is noteworthy
that the vapor permeability decreases with increasing the particle
concentration in the polymer–particle composite film. The reduction
of water vapor permeability is obviously associated with the density of
the aggregates formed on the surface of the treated marbles. As the
coverage of the marble surfaces by the protrusions increases, the
vapor flow is inhibited. The reduction of the vapor permeability
caused by the polymer–particle composite films is not negligible, but
it is lower than the reduction reported for the fluorinated acrylic
copolymers [27].
Fig. 5. Reduction of water capillary absorption vs. silica nanoparticle concentration.
Fig. 4. Consecutive images of a water droplet bouncing and rolling off a Pentelic marble treated with Rhodorsil and 1.5% w/v silica nanoparticles.
1326 P.N. Manoudis et al. / Surface & Coatings Technology 203 (2009) 1322–1328
6. 3.5. Color alteration
The variation on the optical appearance of the treated marbles was
evaluated with colorimetric measurements. An ideal protective
coating should not have any impact on the optical appearance of the
stone. The total color difference (ΔΕ⁎) on the same spot of the same
sample before and after treatment is defined as:
ΔET =
ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
ΔLT2
+ ΔaT2
+ ΔbT2
p
ð4Þ
L⁎: brightness (0 for black–100 for white)
a⁎: red–green component (positive for red and negative for the green
colors)
b⁎: yellow–blue component (positive for yellow and negative for the
blue colors).
The total color difference results are presented in Fig. 7. At low
particle concentration, the color difference due to the polymer–
particle composite films is lower compared to the color difference
caused by pure siloxane. At elevated particle content, the dense surface
morphology results in an enhancement of ΔΕ⁎, which increases with
particle concentration in the polymer particle composite film. The
maximum total color difference is caused by the polymer and 2% w/v
silica particles. The maximum ΔΕ⁎ obtained on the marbles is
comparable with the ΔΕ⁎ caused by the application of various pure
polymer films on the same marble [3].
It is noteworthy that the color difference is mainly caused by
changes in the brightness (L⁎) of the treated marbles. In particular, the
pure polymer film slightly reduces the brightness of marble surface in
accordance with the previous results [3]. On the contrary, due to the
high brightness value of nanoparticles itself (L⁎=88.0), their addition
restores and, at higher concentrations, even enhances the brightness of
the marbles' surface. This is especially evident for the relatively “dark”
marble of Thassos, where the brightness of the untreated sample
increased from 69.1±1 to 76±0.8, in the case of 2% w/v nanoparticles.
The red–green chromatic component a⁎ (positive for red and
negative for green colors) remained practically unaltered. Similarly,
for the yellow–blue chromatic component b⁎ (positive for yellow and
negative for blue colors), no significant variations were observed, that
is, no yellowing was measured.
The acquired results demonstrate that the addition of nanoparti-
cles affects mainly the brightness of treated white marble surfaces
without affecting the other color components (a⁎ and b⁎).
3.6. Outdoor exposure
The protective treatments on stones, which include polymers, are
usually sensitive to environmental parameters like UV irradiation. The
photochemical stability of the polymers used for the protection of
monuments has been extensively studied mainly under artificial light
irradiation [28–30]. In an environmental chamber, however, para-
meters like rainfall and dust deposition cannot be studied and
atmospheric pollution can be simulated to a certain degree only. For
this purpose and in order to evaluate the durability of the protective
treatment, a Pentelic marble treated with siloxane and 2% w/v
nanoparticles was exposed to outdoor conditions. After 5 months of
outdoor exposure, water contact angle measurements were carried
out on the marble. The static water contact angle was reduced from
162±1.5° to 150±1°. The obtained results show that, despite the
reduction in water contact angle, the treated marble surface remained
super-hydrophobic and thus, they demonstrate the durability of the
suggested treatment.
4. Concluding remarks
Our data demonstrate that the modification of the commercial
siloxane protective composition by the addition of silica nanoparticles
with nominal diameter 7 nm can substantially enhance the efficiency
of the composition for the protection of stone buildings and
monuments. The application of the modified composition on Greek
marble substrates (marbles of Naxos, Pentelic and Thassos) render the
treated surfaces superhydrophobic with highly water-repellent and
self-cleaning properties. The enhancement of the protection efficiency
depends on the nanoparticle concentration. For nanoparticle concen-
trations N1% w/v (e.g. 1, 1.5 and 2%), the acquired hydrophobic
properties are independent of the nature of the substrate and are
characterized by water contact angle of about 160° and by contact
angle hysteresis of 5°. The observed effect is explained by changes in
the surface morphology of the treated marbles caused by the addition
of nanoparticles. Initially (0% nanoparticles in siloxane protective
composition), there is a thin polymer protective film, which follows
the morphology of the substrate surface. The addition of nanoparticles
leads to the formation of superficial micron-sized protrusions with
highly developed nanostructure. The size (10–100 μm) and the surface
density of these protrusions depend on the nanoparticle concentra-
tion in a proportional way. Apparently, the alteration of the surface
morphology changes the wetting mode of the surface from initially
homogeneous (Wenzel model) to heterogeneous (Cassie-Baxter
model) mode, where substantial amount of air is trapped in-between
the water droplet and the substrate. The latter mode is often referred
Fig. 6. Reduction of water vapor permeability vs. silica nanoparticle concentration.
Fig. 7. Total color variation (ΔΕ⁎) vs. silica nanoparticle concentration.
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P.N. Manoudis et al. / Surface & Coatings Technology 203 (2009) 1322–1328
7. as “slippery” regime and is characterized by a small contact angle
hysteresis and thus a small sliding or tilt angle [31,32]. In the approach
reported here, the contact angle hysteresis reached very low values of
about 5° on all the marbles treated with the modified composition of
more than 1% w/v nanoparticles.
The nano dimensions of silica particles are essential for the
superhydrophobization of the treated marble surfaces. In the case of
micron-sized silica particles (mean diameter ~3 μm) that were used
and applied by the same methodology, the superhydrophobic effect
was not achieved and the observed water contact angles were
substantially lower. We suggest that the nano dimensions of particles
are important for the formation of the developed nanostructure/nano
roughness of the protective layer. Nano-roughness together with
micro-roughness (assured by silica micro-protrusions) is equally
important for the development of surface super-hydrophobicity.
Concerning the other parameters, which are also important for the
efficient protection of the stone monuments and buildings, namely the
reduction of water capillary absorption and the stone permeability to
water vapor, the optimal concentration for the nanoparticles can be
indicated. At this concentration, namely 1.5% w/v of nanoparticles, the
modified Rhodorsil composition offers sufficiently enhanced, optimal
protection for marble monuments and buildings. This modified
composition renders their surface super-hydrophobic and self-clean-
ing, considerably reduces (from 89.5±0.7 to 96±1%) water capillary
absorption and, albeit decrease water vapor permeability, still
maintains it at an acceptable level.
The suggested modification is simple, cost-effective and an
efficient approach for the improved protection of stone monuments
and buildings from decay and deterioration.
Acknowledgements
This research was supported by PENED 2003 program that is co-
financed by E.U.-European Social Fund (75%) and the Greek Ministry of
Development-GSRT (25%). The support of Greek State Scholarship
Foundation to P.M. is also gratefully acknowledged. The authors are
also grateful to Dr. S. Marras for the SEM images.
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