Abstract
With the rapid advancement in concrete technology, demand for sustainable building materials has increased manifold in last few
decades. High strength concrete such as Self compacting concrete (SCC), also known as Self consolidated concrete, is considered
one of the finest and highly modified concrete material. SCC represents a major evolution in the building industry. The increased
use of SCC for construction and repair purposes lies in the fact that it is semi-flowable in nature and possess several advantages
such as environmental, human, technological and economical. This paper mainly focuses on the effect of various shrinkage
properties such as drying shrinkage, autogenous shrinkage and plastic shrinkage on performance of SCC. Detailed literature
review suggests that early age shrinkage in SCC has been a major setback in attaining it’s desired strength. Expansive cracking
and capillary tension are considered as two main phenomena behind shrinkage in SCC. It is found out that factors like lower
water/cement ratio or decreasing limestone filler/cement ratio leads to reduction in autogenous shrinkage. It is considered that
cracks are one of the pivotal reasons behind the poor durability of concrete as they help in entering hazardous fluids. Hence
cracks causes specific problems like plastic shrinkage. The effect of shrinkage reducing admixtures (SRA) on SCC was observed
to be positive. SRA along with paraffin based curing compounds helps in reducing cracks. It was observed from rheological tests
conducted on concrete as well as fresh SCC that, as far as drying shrinkage is concerned usage of SRA was found out to be
effective while hydrophobizing admixtures tends to be useless. Along with addition of such admixtures, limestone fines in SCC
mixes shows a reduction in autogenous shrinkage in SCC as compared to normal vibrated concrete (NVC). More importantly
results show that total shrinkage in SCC mixed with limestone filler is slightly higher (not >9.2%) than in NVC, while SCC made
with viscous Modifying Agents (VMA) shows 7.7% less shrinkage than in NVC, due to lower autogenous and drying shrinkage.
Keywords: Admixtures, Capillary Tension, Cement/Binder Ratio, Cracking, Shrinkage, Viscous Modifying Agents
Rheology of Fresh Self Compacted Concrete - Concrete Shear Box_ Ajay and Dr.G...ajay nagaraj
Flow characterization and controlling fresh property of SCC is most critical. Even slight variations in ingredients can have adverse effect on fresh properties; strength and durability of hardened concrete. The material science approach to study rheological properties is essential in order to overcome the paucity posed while characterizing mixes by empirical methods such as the slump flow test.
In the present work, the Bingham parameters of SCC were assessed by using the new concrete shear box. The mixes were designed considering volume of paste based on absolute volume concept. Three different volumes of pastes (0.38, 0.40 and 0.42) with water contents of 170 and 190 lt/m3 and cement contents of 300 and 450 kg/m3 along with slag as filler was used. A unique test procedure was followed, by applying low normal stresses of 0.10, 0.20 and 0.30 MPa with three different displacement rates of 1, 5 and 15mm/min under static condition. The results indicate that the new concrete shear box shall effectively put to use, as an additional tool for evaluating the rheological properties of SCC viz., yield stress and plastic viscosity
Experimental Study on Performance of Metakaolin in Pervious ConcreteYogeshIJTSRD
Lately, part of examination center around growing new Supplementary cementitious material to fortifying the solid. These materials are utilized as a piece of concretes. Metakaolin is one of the beneficial cementitious materials which are part of the way traded for concrete. Properties of cement with metakaolin are generally favored added substances in concrete. Pervious cement is an uncommon kind of cement with a high porosity utilized for solid flatwork applications that permits water from precipitation and different sources to go straightforwardly through, in this manner diminishing the spillover from a site and permitting groundwater re energize. It likewise called as Porous concrete, Permeable concrete, No fines concrete and Porous asphalt. Pervious cement is generally utilized in stopping zones, territories with light traffic, Residential roads, Pedestrian walkways and nurseries. It is a significant application for manageable development. Metakaolin will be added at various rates or percentages such as 1 ,1.5 ,2 ,2.5 by the heaviness of concrete. To make concrete cubes and cylinders at every percent. The effect of metakaolin at various percents in pervious concrete will be finding by conducting compression test. A. Thomas Eucharist | K. Viswanathan "Experimental Study on Performance of Metakaolin in Pervious Concrete" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-4 , June 2021, URL: https://www.ijtsrd.compapers/ijtsrd41139.pdf Paper URL: https://www.ijtsrd.comengineering/civil-engineering/41139/experimental-study-on-performance-of-metakaolin-in-pervious-concrete/a-thomas-eucharist
Creep is defined as the plastic deformation under sustain load. Creep strain depends
primarily on the duration of sustained loading. It has been widely acknowledged that creep of
concrete is greatly influenced by the surrounding ambient. Creep induces the deflection of the
structural member with time. Hence the study on creep of concrete is necessary to prevent failure. A
concrete cylinder is casted for two different grades and the load of 40% of its compressive strength
is applied constantly. Creep is measured with time. A time - dependent creep is provided in a graph
showing its variation.
Rheology of Fresh Self Compacted Concrete - Concrete Shear Box_ Ajay and Dr.G...ajay nagaraj
Flow characterization and controlling fresh property of SCC is most critical. Even slight variations in ingredients can have adverse effect on fresh properties; strength and durability of hardened concrete. The material science approach to study rheological properties is essential in order to overcome the paucity posed while characterizing mixes by empirical methods such as the slump flow test.
In the present work, the Bingham parameters of SCC were assessed by using the new concrete shear box. The mixes were designed considering volume of paste based on absolute volume concept. Three different volumes of pastes (0.38, 0.40 and 0.42) with water contents of 170 and 190 lt/m3 and cement contents of 300 and 450 kg/m3 along with slag as filler was used. A unique test procedure was followed, by applying low normal stresses of 0.10, 0.20 and 0.30 MPa with three different displacement rates of 1, 5 and 15mm/min under static condition. The results indicate that the new concrete shear box shall effectively put to use, as an additional tool for evaluating the rheological properties of SCC viz., yield stress and plastic viscosity
Experimental Study on Performance of Metakaolin in Pervious ConcreteYogeshIJTSRD
Lately, part of examination center around growing new Supplementary cementitious material to fortifying the solid. These materials are utilized as a piece of concretes. Metakaolin is one of the beneficial cementitious materials which are part of the way traded for concrete. Properties of cement with metakaolin are generally favored added substances in concrete. Pervious cement is an uncommon kind of cement with a high porosity utilized for solid flatwork applications that permits water from precipitation and different sources to go straightforwardly through, in this manner diminishing the spillover from a site and permitting groundwater re energize. It likewise called as Porous concrete, Permeable concrete, No fines concrete and Porous asphalt. Pervious cement is generally utilized in stopping zones, territories with light traffic, Residential roads, Pedestrian walkways and nurseries. It is a significant application for manageable development. Metakaolin will be added at various rates or percentages such as 1 ,1.5 ,2 ,2.5 by the heaviness of concrete. To make concrete cubes and cylinders at every percent. The effect of metakaolin at various percents in pervious concrete will be finding by conducting compression test. A. Thomas Eucharist | K. Viswanathan "Experimental Study on Performance of Metakaolin in Pervious Concrete" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-4 , June 2021, URL: https://www.ijtsrd.compapers/ijtsrd41139.pdf Paper URL: https://www.ijtsrd.comengineering/civil-engineering/41139/experimental-study-on-performance-of-metakaolin-in-pervious-concrete/a-thomas-eucharist
Creep is defined as the plastic deformation under sustain load. Creep strain depends
primarily on the duration of sustained loading. It has been widely acknowledged that creep of
concrete is greatly influenced by the surrounding ambient. Creep induces the deflection of the
structural member with time. Hence the study on creep of concrete is necessary to prevent failure. A
concrete cylinder is casted for two different grades and the load of 40% of its compressive strength
is applied constantly. Creep is measured with time. A time - dependent creep is provided in a graph
showing its variation.
Segregation in Concrete
The main explanation of this report of Segregation in concrete in terms of
concrete and self-compacting. The aim was to find an analytical relation to
estimating the risk of sedimentation, using the characteristics of the particles
and those of the mortars. The prediction of surface effect segregation (i.e.
transportation of different particle size fractions during heap formation) has
been the subject of a significant level of study.
Explanation of the type of segregation in term size, dry, wet, and water separate
and effect segregation in concrete in term strength and cracks, and
Prevention of Segregation in Concrete.
I brought up an example that supports segregation in concrete which is used
in Kurdistan Region, and explaining the example in term caused segregation
the effect in concrete.
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.
A Study on Cube and Cylinder Strength of Brick Aggregate ConcreteIOSR Journals
: Concrete is unique and extensively conducive construction material by virtue of its excellent
compressive strength, which is one of the most important and useful properties of concrete. In most structural
applications, concrete is employed primarily to resist compressive stresses, which depends on plenty of factors
like properties of ingredients, design method of preparation, curing conditions etc. Generally, compressive
strength of concrete is referred to either cube strength or cylinder strength. The compressive strength of
concrete is determined by testing cubes or cylinders made in laboratory or field or cores drilled from hardened
concrete at site or from the non-destructive testing of the specimen or actual structure. The main objective of
this research was to make comparison of strength between cube and cylinder using brick aggregate concrete.
For this purpose, nine sets of mix proportions were made and studied the variation of strength between cube
and cylinder. Along with this, variation of strengths between standard and small cylinders was also observed.
Moreover, concrete was designed for two specified compressive strengths (3000 psi and 4500 psi) by American
Concrete Institute (ACI) mix design procedure. Then it was casted and tested in laboratory with proper care.
From the analysis of the test results, it had been found that cylinder strength was approximately 86 to 90
percent of cube strength and small cylinder strength was approximately 91 to 94 percent of standard cylinder
strength
Curing Methods and Their Effects on The Strength of ConcreteIJERA Editor
There are a lot of arguments on which method of curing concrete gives good strength. These different opinions results into this study, which aim at investigating the effects of different curing methods on the strength of concrete. Laboratory test was employed for this study. Normal concretes were prepared using specified mix ratio of 1:2:4 and 1:3:6. The cubes tested for compressive strength at 3, 7, 21, and 28 days of curing respectively using four curing methods namely immersion, sprinkling, polythene sheeting and sharp sand coating. Testing indicate that water immersion curing method as well as sprinkling (spraying ) methods of curing, provide better results than membrane (polythene sheeting) method of curing. While sharp sand gives least strength. The rate of drying was significant when the specimens were subjected to curing with polythene sheet method of curing. This thus hampered the hydration process and thus affected the compressive strength property of the hardened concrete. The overall findings of this study suggests that concrete should be cured by water immersion or spraying regularly to achieve a better compressive strength in concrete.
30 BIG TECH
PREDICTIONS FOR 2017
THIRTY PREDICTIONS ACROSS MOBILE, DIGITAL MEDIA,
PAYMENTS, E-COMMERCE, INTERNET OF THINGS, AND
FINTECH FOR 2017
January 2017
The BI Intelligence Research Team
https://plus.google.com/+BusinessInsider
https://en.wikipedia.org/wiki/Business_intelligence
http://www.businessinsider.com/intelligence/bi-intelligence-all-access-membership
Segregation in Concrete
The main explanation of this report of Segregation in concrete in terms of
concrete and self-compacting. The aim was to find an analytical relation to
estimating the risk of sedimentation, using the characteristics of the particles
and those of the mortars. The prediction of surface effect segregation (i.e.
transportation of different particle size fractions during heap formation) has
been the subject of a significant level of study.
Explanation of the type of segregation in term size, dry, wet, and water separate
and effect segregation in concrete in term strength and cracks, and
Prevention of Segregation in Concrete.
I brought up an example that supports segregation in concrete which is used
in Kurdistan Region, and explaining the example in term caused segregation
the effect in concrete.
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.
A Study on Cube and Cylinder Strength of Brick Aggregate ConcreteIOSR Journals
: Concrete is unique and extensively conducive construction material by virtue of its excellent
compressive strength, which is one of the most important and useful properties of concrete. In most structural
applications, concrete is employed primarily to resist compressive stresses, which depends on plenty of factors
like properties of ingredients, design method of preparation, curing conditions etc. Generally, compressive
strength of concrete is referred to either cube strength or cylinder strength. The compressive strength of
concrete is determined by testing cubes or cylinders made in laboratory or field or cores drilled from hardened
concrete at site or from the non-destructive testing of the specimen or actual structure. The main objective of
this research was to make comparison of strength between cube and cylinder using brick aggregate concrete.
For this purpose, nine sets of mix proportions were made and studied the variation of strength between cube
and cylinder. Along with this, variation of strengths between standard and small cylinders was also observed.
Moreover, concrete was designed for two specified compressive strengths (3000 psi and 4500 psi) by American
Concrete Institute (ACI) mix design procedure. Then it was casted and tested in laboratory with proper care.
From the analysis of the test results, it had been found that cylinder strength was approximately 86 to 90
percent of cube strength and small cylinder strength was approximately 91 to 94 percent of standard cylinder
strength
Curing Methods and Their Effects on The Strength of ConcreteIJERA Editor
There are a lot of arguments on which method of curing concrete gives good strength. These different opinions results into this study, which aim at investigating the effects of different curing methods on the strength of concrete. Laboratory test was employed for this study. Normal concretes were prepared using specified mix ratio of 1:2:4 and 1:3:6. The cubes tested for compressive strength at 3, 7, 21, and 28 days of curing respectively using four curing methods namely immersion, sprinkling, polythene sheeting and sharp sand coating. Testing indicate that water immersion curing method as well as sprinkling (spraying ) methods of curing, provide better results than membrane (polythene sheeting) method of curing. While sharp sand gives least strength. The rate of drying was significant when the specimens were subjected to curing with polythene sheet method of curing. This thus hampered the hydration process and thus affected the compressive strength property of the hardened concrete. The overall findings of this study suggests that concrete should be cured by water immersion or spraying regularly to achieve a better compressive strength in concrete.
30 BIG TECH
PREDICTIONS FOR 2017
THIRTY PREDICTIONS ACROSS MOBILE, DIGITAL MEDIA,
PAYMENTS, E-COMMERCE, INTERNET OF THINGS, AND
FINTECH FOR 2017
January 2017
The BI Intelligence Research Team
https://plus.google.com/+BusinessInsider
https://en.wikipedia.org/wiki/Business_intelligence
http://www.businessinsider.com/intelligence/bi-intelligence-all-access-membership
Japan turns on the charm in myanmar in effort to counter china ဂ်ပန္ေတြ ျမန္မ...MYO AUNG Myanmar
BURMESE VERSION
စီးပြားေရး
ဂ်ပန္ေတြ ျမန္မာကို ဝင္ေနျပီ
ဧရာ၀တီ| July 14, 2016
http://burma.irrawaddy.com/business/2016/07/14/118414.html
ENGLISH VERSION
http://www.ft.com/cms/s/0/90c08c6a-3f72-11e6-8716-a4a71e8140b0.html#axzz4ENn68x5v
Japan turns on the charm in Myanmar in effort to counter China-ဂ်ပန္ေတြ ျမန္မာကို ဝင္ေနျပီ
Japan turns on the charm in Myanmar in effort to counter China Investment spree part of a wider Japanese push to win markets and reduce dependence on Beijing
Japan has intensified its charm and investment offensive in Myanmar in a bid to become Southeast Asia’s most powerful counterbalance to China.
Poor and Rich - The Facts
DEFINING POVERTY...
Absolute poverty is defined according to an absolute minimum standard, often called the ‘poverty line’. Relative poverty means that you are poor in relation to those around you. Income poverty (‘less than a dollar a day’, for example), means that you are poor if you have less money than the defined poverty line for your country. Human poverty takes into account other factors, such as life expectancy, infant malnutrition, illiteracy and lack of food or clean water. Basic needs definitions also go beyond money, to include all the things that a person needs in order to survive – including employment and participation in society.
MEASURING POVERTY...
Measuring poverty is always a problem, especially if you recognize that just using money is not enough. There are a number of new measurements emerging, like the Index of Sustainable Economic Welfare.1 This measures ‘quality’ economic activity by, for example, making a subtraction for air pollution and an addition for unpaid household labour.
Another method is the Human Poverty Index. This is ranked according to three main areas of deprivation: survival; knowledge and a decent standard of living. In the industrial world, where the Index also includes social exclusion, some 7 to 17% of the populations are classified as poor. The higher the percentage figure, the greater the poverty in that country
Outcrops of SG_KK & KL_August 2016_Final_20.09.16KYI KHIN
This compilation was aimed to record for rare geological outcrops which were gradually diminished by infrastructural and construction projects.
Sharing information among fellow geologists working in Singapore and abroad.
The Republic of the Union of Myanmar Ministry of Electricity and Energy Hydro...MYO AUNG Myanmar
THE REPUBLIC OF THE UNION OF MYANMAR
MINISTRY OF ELECTRICITY AND ENERGY
HYDROPOWER DEVELOPMENT PLANS
http://www.ifc.org/wps/wcm/connect/e46682d2-cc3a-4d3c-9bc5-02496244c6b9/IFC's+General+Forum++(11+8+2016)UAKK.pdf?MOD=AJPERES
Hydropower Potential in Myanmar
Durability Study on Self Compacting Concrete with Mineral Admixtureijtsrd
Self compacting concrete can be placed and compacted under its own weight without any vibration and without segregation or bleeding. The use of mineral admixture such as fly ash, GGBS, etc. as partial replacement of cement in SCC can bring down cost. The use of industrial waste such as fly ash, GGBS, etc in the binder of concrete reduces the storage, disposal and environmental problems. The most beneficial property with M SAND addition to the concrete in the hardened state are the tensile strength, impact strength, the toughness and the energy absorption capacity. In the present study the mix design for M50 grade SCC was first carried out in accordance with EFNARC guidelines. The cement will be replaced with GGBS and fine aggregate get replaced with manufacturing sand Test such as slump flow,V funnel were carried out on fresh concrete and the optimum dosage of super plasticizer was found and cubes were cast for 7,28,56 days for the mix ratio 1 1.40 1.27 0.34. The influence of GGBS on the workability, mechanical strength and durability aspects like water absorption test, sulphate attack test, acid resistance test,rapid chloride penetration test , sorptivity test , linear polarization resistivity test and alkalinity test of self compacting concrete are studied. Boopathi V | Sharmila Devi K ""Durability Study on Self Compacting Concrete with Mineral Admixture"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23226.pdf
Paper URL: https://www.ijtsrd.com/engineering/civil-engineering/23226/durability-study-on-self-compacting-concrete-with-mineral-admixture/boopathi-v
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
An experimental study on durability of high strength self compacting concrete...eSAT Journals
Abstract The basic philosophy in the construction of every structure is it should perform its intended functions successfully through the expected and anticipated life time, irrespective of external exposure conditions. The ability of the concrete is to resist and withstand any environmental conditions that may result in early failure or severe damages and it is a major concern to the engineering professional. Out of all the deteriorating agents acid attack is one of the phenomena that plays a vital role in disintegrating concrete structures depending on the type and concentration of the acid. Certain acids are harmless. The present investigation focused on the effect of H2 So4 and HCL on High Strength Self Compacting Concrete. Keywords: Self Compacting Concrete, Durability, deterioration, Compressive strength, viscosity modifying agent, Workability
Development of high-strength, economical self-consolidating concretePubl 2022
Naık T. R. , Kumar R., Ramme B. W. , Canpolat F.
This paper presents information regarding development, properties, and advantages and disadvantages of using high-strength self-consolidating concrete in the construction industry. It also presents results of a study recently completed for manufacturing economical high-strength self-consolidating concrete containing high-volumes of fly ash. In this study, portland cement was replaced by Class C fly ash in the range of 35-55% by the mass of cement. The results of fresh and hardened properties of concrete show that the use of high-volumes of Class C fly ash in self-consolidating concrete reduces the requirements for superplasticizer (HRWRA) and viscosity modifying agent (VMA) compared with the normal dosage for such admixtures in self-Consolidating concrete. The results further indicate that economical self-consolidating concrete with 28-day strengths up to 62 MPa can be made using high-volumes of fly ash. Such concretes can be used for a wide range of applications from cast-in-place to precast concrete construction.
DOI:10.1016/j.conbuildmat.2011.12.025
Self compacting concrete for slip form pavingeSAT Journals
Abstract Slip form paving has been extensively used worldwide for construction of pavements. During the process of paving, concrete mix with a slump less than 50 mm is placed in front of a paver. Because of the low consistency of the mix, a great deal of vibration is needed to move entrapped air and compact the concrete. There is a need to overcome problem by designing a concrete that would not require vibration to compact the concrete mix, at the same time stability after extrusion and high flexural strength. Mix design based on the absolute volume concept was adopted to fabricate SFSCC. Volume of paste of 0.38 and water content of 200 kg/m3 was kept constant throughout the study. Cement content was varied from 360 to 425 kg/m3, 3 mixes of SCC with GGBS (SFSCC-S), 3 mixes of SCC with 2% of alccofine replaced by cement (SFSCC-SA) and 3 mixes of SCC with 2% of metakaolin replaced by cement (SFSCC-SM) is reported. The quantity of polypropylene fibers used in all the mixes was 900 gm/m3. Slump, spread, green strength and compaction factor were evaluated for all the 9 mixes. To simulate the practical construction process, a mini paver system was fabricated. The strength parameters compressive and flexural strength of concrete was evaluated at 7 days and 28 days. Keywords: Slip form paving, alccofine, SCC, GGBS, metakaolin, SFSCC, SP.
Mechanical properties of hybrid fiber reinforced concrete for pavementseSAT Journals
Abstract
The effect of addition of mono fibers and hybrid fibers on the mechanical properties of concrete mixture is studied in the present
investigation. Steel fibers of 1% and polypropylene fibers 0.036% were added individually to the concrete mixture as mono fibers and
then they were added together to form a hybrid fiber reinforced concrete. Mechanical properties such as compressive, split tensile and
flexural strength were determined. The results show that hybrid fibers improve the compressive strength marginally as compared to
mono fibers. Whereas, hybridization improves split tensile strength and flexural strength noticeably.
Keywords:-Hybridization, mono fibers, steel fiber, polypropylene fiber, Improvement in mechanical properties.
Material management in construction – a case studyeSAT Journals
Abstract
The objective of the present study is to understand about all the problems occurring in the company because of improper application
of material management. In construction project operation, often there is a project cost variance in terms of the material, equipments,
manpower, subcontractor, overhead cost, and general condition. Material is the main component in construction projects. Therefore,
if the material management is not properly managed it will create a project cost variance. Project cost can be controlled by taking
corrective actions towards the cost variance. Therefore a methodology is used to diagnose and evaluate the procurement process
involved in material management and launch a continuous improvement was developed and applied. A thorough study was carried
out along with study of cases, surveys and interviews to professionals involved in this area. As a result, a methodology for diagnosis
and improvement was proposed and tested in selected projects. The results obtained show that the main problem of procurement is
related to schedule delays and lack of specified quality for the project. To prevent this situation it is often necessary to dedicate
important resources like money, personnel, time, etc. To monitor and control the process. A great potential for improvement was
detected if state of the art technologies such as, electronic mail, electronic data interchange (EDI), and analysis were applied to the
procurement process. These helped to eliminate the root causes for many types of problems that were detected.
Managing drought short term strategies in semi arid regions a case studyeSAT Journals
Abstract
Drought management needs multidisciplinary action. Interdisciplinary efforts among the experts in various fields of the droughts
prone areas are helpful to achieve tangible and permanent solution for this recurring problem. The Gulbarga district having the total
area around 16, 240 sq.km, and accounts 8.45 per cent of the Karnataka state area. The district has been situated with latitude 17º 19'
60" North and longitude of 76 º 49' 60" east. The district is situated entirely on the Deccan plateau positioned at a height of 300 to
750 m above MSL. Sub-tropical, semi-arid type is one among the drought prone districts of Karnataka State. The drought
management is very important for a district like Gulbarga. In this paper various short term strategies are discussed to mitigate the
drought condition in the district.
Keywords: Drought, South-West monsoon, Semi-Arid, Rainfall, Strategies etc.
Life cycle cost analysis of overlay for an urban road in bangaloreeSAT Journals
Abstract
Pavements are subjected to severe condition of stresses and weathering effects from the day they are constructed and opened to traffic
mainly due to its fatigue behavior and environmental effects. Therefore, pavement rehabilitation is one of the most important
components of entire road systems. This paper highlights the design of concrete pavement with added mono fibers like polypropylene,
steel and hybrid fibres for a widened portion of existing concrete pavement and various overlay alternatives for an existing
bituminous pavement in an urban road in Bangalore. Along with this, Life cycle cost analyses at these sections are done by Net
Present Value (NPV) method to identify the most feasible option. The results show that though the initial cost of construction of
concrete overlay is high, over a period of time it prove to be better than the bituminous overlay considering the whole life cycle cost.
The economic analysis also indicates that, out of the three fibre options, hybrid reinforced concrete would be economical without
compromising the performance of the pavement.
Keywords: - Fatigue, Life cycle cost analysis, Net Present Value method, Overlay, Rehabilitation
Laboratory studies of dense bituminous mixes ii with reclaimed asphalt materialseSAT Journals
Abstract
The issue of growing demand on our nation’s roadways over that past couple of decades, decreasing budgetary funds, and the need to
provide a safe, efficient, and cost effective roadway system has led to a dramatic increase in the need to rehabilitate our existing
pavements and the issue of building sustainable road infrastructure in India. With these emergency of the mentioned needs and this
are today’s burning issue and has become the purpose of the study.
In the present study, the samples of existing bituminous layer materials were collected from NH-48(Devahalli to Hassan) site.The
mixtures were designed by Marshall Method as per Asphalt institute (MS-II) at 20% and 30% Reclaimed Asphalt Pavement (RAP).
RAP material was blended with virgin aggregate such that all specimens tested for the, Dense Bituminous Macadam-II (DBM-II)
gradation as per Ministry of Roads, Transport, and Highways (MoRT&H) and cost analysis were carried out to know the economics.
Laboratory results and analysis showed the use of recycled materials showed significant variability in Marshall Stability, and the
variability increased with the increase in RAP content. The saving can be realized from utilization of recycled materials as per the
methodology, the reduction in the total cost is 19%, 30%, comparing with the virgin mixes.
Keywords: Reclaimed Asphalt Pavement, Marshall Stability, MS-II, Dense Bituminous Macadam-II
Laboratory investigation of expansive soil stabilized with natural inorganic ...eSAT Journals
Abstract
Soil stabilization has proven to be one of the oldest techniques to improve the soil properties. Literature review conducted revealed
that uses of natural inorganic stabilizers are found to be one of the best options for soil stabilization. In this regard an attempt has
been made to evaluate the influence of RBI-81 stabilizer on properties of black cotton soil through laboratory investigations. Black
cotton soil with varying percentages of RBI-81 viz., 0, 0.5, 1, 1.5, 2, and 2.5 percent were studied for moisture density relationships
and strength behaviour of soils. Also the effect of curing period was evaluated as literature review clearly emphasized the strength
gain of soils stabilized with RBI-81 over a period of time. The results obtained shows that the unconfined compressive strength of
specimens treated with RBI-81 increased approximately by 250% for a curing period of 28 days as compared to virgin soil. Further
the CBR value improved approximately by 400%. The studies indicated an increasing trend for soil strength behaviour with
increasing percentage of RBI-81 suggesting its potential applications in soil stabilization.
Influence of reinforcement on the behavior of hollow concrete block masonry p...eSAT Journals
Abstract
Reinforced masonry was developed to exploit the strength potential of masonry and to solve its lack of tensile strength. Experimental
and analytical studies have been carried out to investigate the effect of reinforcement on the behavior of hollow concrete block
masonry prisms under compression and to predict ultimate failure compressive strength. In the numerical program, three dimensional
non-linear finite elements (FE) model based on the micro-modeling approach is developed for both unreinforced and reinforced
masonry prisms using ANSYS (14.5). The proposed FE model uses multi-linear stress-strain relationships to model the non-linear
behavior of hollow concrete block, mortar, and grout. Willam-Warnke’s five parameter failure theory has been adopted to model the
failure of masonry materials. The comparison of the numerical and experimental results indicates that the FE models can successfully
capture the highly nonlinear behavior of the physical specimens and accurately predict their strength and failure mechanisms.
Keywords: Structural masonry, Hollow concrete block prism, grout, Compression failure, Finite element method,
Numerical modeling.
Influence of compaction energy on soil stabilized with chemical stabilizereSAT Journals
Abstract
Increase in traffic along with heavier magnitude of wheel loads cause rapid deterioration in pavements. There is a need to improve
density, strength of soil subgrade and other pavement layers. In this study an attempt is made to improve the properties of locally
available loamy soil using twin approaches viz., i) increasing the compaction of soil and ii) treating the soil with chemical stabilizer.
Laboratory studies are carried out on both untreated and treated soil samples compacted by different compaction efforts. Studies
show that increase in compaction effort results in increase in density of soil. However in soil treated with chemical stabilizer, rate of
increase in density is not significant. The soil treated with chemical stabilizer exhibits improvement in both strength and performance
properties.
Keywords: compaction, density, subgradestabilization, resilient modulus
Geographical information system (gis) for water resources managementeSAT Journals
Abstract
Water resources projects are inherited with overlapping and at times conflicting objectives. These projects are often of varied sizes
ranging from major projects with command areas of millions of hectares to very small projects implemented at the local level. Thus,
in all these projects there is seldom proper coordination which is essential for ensuring collective sustainability.
Integrated watershed development and management is the accepted answer but in turn requires a comprehensive framework that can
enable planning process involving all the stakeholders at different levels and scales is compulsory. Such a unified hydrological
framework is essential to evaluate the cause and effect of all the proposed actions within the drainage basins.
The present paper describes a hydrological framework developed in the form of a Hydrologic Information System (HIS) which is
intended to meet the specific information needs of the various line departments of a typical State connected with water related aspects.
The HIS consist of a hydrologic information database coupled with tools for collating primary and secondary data and tools for
analyzing and visualizing the data and information. The HIS also incorporates hydrological model base for indirect assessment of
various entities of water balance in space and time. The framework would be maintained and updated to reflect fully the most
accurate ground truth data and the infrastructure requirements for planning and management.
Keywords: Hydrological Information System (HIS); WebGIS; Data Model; Web Mapping Services
Forest type mapping of bidar forest division, karnataka using geoinformatics ...eSAT Journals
Abstract
The study demonstrate the potentiality of satellite remote sensing technique for the generation of baseline information on forest types
including tree plantation details in Bidar forest division, Karnataka covering an area of 5814.60Sq.Kms. The Total Area of Bidar
forest division is 5814Sq.Kms analysis of the satellite data in the study area reveals that about 84% of the total area is Covered by
crop land, 1.778% of the area is covered by dry deciduous forest, 1.38 % of mixed plantation, which is very threatening to the
environmental stability of the forest, future plantation site has been mapped. With the use of latest Geo-informatics technology proper
and exact condition of the trees can be observed and necessary precautions can be taken for future plantation works in an appropriate
manner
Keywords:-RS, GIS, GPS, Forest Type, Tree Plantation
Factors influencing compressive strength of geopolymer concreteeSAT Journals
Abstract
To study effects of several factors on the properties of fly ash based geopolymer concrete on the compressive strength and also the
cost comparison with the normal concrete. The test variables were molarities of sodium hydroxide(NaOH) 8M,14M and 16M, ratio of
NaOH to sodium silicate (Na2SiO3) 1, 1.5, 2 and 2.5, alkaline liquid to fly ash ratio 0.35 and 0.40 and replacement of water in
Na2SiO3 solution by 10%, 20% and 30% were used in the present study. The test results indicated that the highest compressive
strength 54 MPa was observed for 16M of NaOH, ratio of NaOH to Na2SiO3 2.5 and alkaline liquid to fly ash ratio of 0.35. Lowest
compressive strength of 27 MPa was observed for 8M of NaOH, ratio of NaOH to Na2SiO3 is 1 and alkaline liquid to fly ash ratio of
0.40. Alkaline liquid to fly ash ratio of 0.35, water replacement of 10% and 30% for 8 and 16 molarity of NaOH and has resulted in
compressive strength of 36 MPa and 20 MPa respectively. Superplasticiser dosage of 2 % by weight of fly ash has given higher
strength in all cases.
Keywords: compressive strength, alkaline liquid, fly ash
Experimental investigation on circular hollow steel columns in filled with li...eSAT Journals
Abstract
Composite Circular hollow Steel tubes with and without GFRP infill for three different grades of Light weight concrete are tested for
ultimate load capacity and axial shortening , under Cyclic loading. Steel tubes are compared for different lengths, cross sections and
thickness. Specimens were tested separately after adopting Taguchi’s L9 (Latin Squares) Orthogonal array in order to save the initial
experimental cost on number of specimens and experimental duration. Analysis was carried out using ANN (Artificial Neural
Network) technique with the assistance of Mini Tab- a statistical soft tool. Comparison for predicted, experimental & ANN output is
obtained from linear regression plots. From this research study, it can be concluded that *Cross sectional area of steel tube has most
significant effect on ultimate load carrying capacity, *as length of steel tube increased- load carrying capacity decreased & *ANN
modeling predicted acceptable results. Thus ANN tool can be utilized for predicting ultimate load carrying capacity for composite
columns.
Keywords: Light weight concrete, GFRP, Artificial Neural Network, Linear Regression, Back propagation, orthogonal
Array, Latin Squares
Experimental behavior of circular hsscfrc filled steel tubular columns under ...eSAT Journals
Abstract
This paper presents an outlook on experimental behavior and a comparison with predicted formula on the behaviour of circular
concentrically loaded self-consolidating fibre reinforced concrete filled steel tube columns (HSSCFRC). Forty-five specimens were
tested. The main parameters varied in the tests are: (1) percentage of fiber (2) tube diameter or width to wall thickness ratio (D/t
from 15 to 25) (3) L/d ratio from 2.97 to 7.04 the results from these predictions were compared with the experimental data. The
experimental results) were also validated in this study.
Keywords: Self-compacting concrete; Concrete-filled steel tube; axial load behavior; Ultimate capacity.
Evaluation of punching shear in flat slabseSAT Journals
Abstract
Flat-slab construction has been widely used in construction today because of many advantages that it offers. The basic philosophy in
the design of flat slab is to consider only gravity forces; this method ignores the effect of punching shear due to unbalanced moments
at the slab column junction which is critical. An attempt has been made to generate generalized design sheets which accounts both
punching shear due to gravity loads and unbalanced moments for cases (a) interior column; (b) edge column (bending perpendicular
to shorter edge); (c) edge column (bending parallel to shorter edge); (d) corner column. These design sheets are prepared as per
codal provisions of IS 456-2000. These design sheets will be helpful in calculating the shear reinforcement to be provided at the
critical section which is ignored in many design offices. Apart from its usefulness in evaluating punching shear and the necessary
shear reinforcement, the design sheets developed will enable the designer to fix the depth of flat slab during the initial phase of the
design.
Keywords: Flat slabs, punching shear, unbalanced moment.
Evaluation of performance of intake tower dam for recent earthquake in indiaeSAT Journals
Abstract
Intake towers are typically tall, hollow, reinforced concrete structures and form entrance to reservoir outlet works. A parametric
study on dynamic behavior of circular cylindrical towers can be carried out to study the effect of depth of submergence, wall thickness
and slenderness ratio, and also effect on tower considering dynamic analysis for time history function of different soil condition and
by Goyal and Chopra accounting interaction effects of added hydrodynamic mass of surrounding and inside water in intake tower of
dam
Key words: Hydrodynamic mass, Depth of submergence, Reservoir, Time history analysis,
Evaluation of operational efficiency of urban road network using travel time ...eSAT Journals
Abstract
Efficiency of the road network system is analyzed by travel time reliability measures. The study overlooks on an important measure of
travel time reliability and prioritizing Tiruchirappalli road network. Traffic volume and travel time were collected using license plate
matching method. Travel time measures were estimated from average travel time and 95th travel time. Effect of non-motorized vehicle
on efficiency of road system was evaluated. Relation between buffer time index and traffic volume was created. Travel time model has
been developed and travel time measure was validated. Then service quality of road sections in network were graded based on
travel time reliability measures.
Keywords: Buffer Time Index (BTI); Average Travel Time (ATT); Travel Time Reliability (TTR); Buffer Time (BT).
Estimation of surface runoff in nallur amanikere watershed using scs cn methodeSAT Journals
Abstract
The development of watershed aims at productive utilization of all the available natural resources in the entire area extending from
ridge line to stream outlet. The per capita availability of land for cultivation has been decreasing over the years. Therefore, water and
the related land resources must be developed, utilized and managed in an integrated and comprehensive manner. Remote sensing and
GIS techniques are being increasingly used for planning, management and development of natural resources. The study area, Nallur
Amanikere watershed geographically lies between 110 38’ and 110 52’ N latitude and 760 30’ and 760 50’ E longitude with an area of
415.68 Sq. km. The thematic layers such as land use/land cover and soil maps were derived from remotely sensed data and overlayed
through ArcGIS software to assign the curve number on polygon wise. The daily rainfall data of six rain gauge stations in and around
the watershed (2001-2011) was used to estimate the daily runoff from the watershed using Soil Conservation Service - Curve Number
(SCS-CN) method. The runoff estimated from the SCS-CN model was then used to know the variation of runoff potential with different
land use/land cover and with different soil conditions.
Keywords: Watershed, Nallur watershed, Surface runoff, Rainfall-Runoff, SCS-CN, Remote Sensing, GIS.
Estimation of morphometric parameters and runoff using rs & gis techniqueseSAT Journals
Abstract
Land and water are the two vital natural resources, the optimal management of these resources with minimum adverse environmental
impact are essential not only for sustainable development but also for human survival. Satellite remote sensing with geographic
information system has a pragmatic approach to map and generate spatial input layers of predicting response behavior and yield of
watershed. Hence, in the present study an attempt has been made to understand the hydrological process of the catchment at the
watershed level by drawing the inferences from moprhometric analysis and runoff. The study area chosen for the present study is
Yagachi catchment situated in Chickamaglur and Hassan district lies geographically at a longitude 75⁰52’08.77”E and
13⁰10’50.77”N latitude. It covers an area of 559.493 Sq.km. Morphometric analysis is carried out to estimate morphometric
parameters at Micro-watershed to understand the hydrological response of the catchment at the Micro-watershed level. Daily runoff
is estimated using USDA SCS curve number model for a period of 10 years from 2001 to 2010. The rainfall runoff relationship of the
study shows there is a positive correlation.
Keywords: morphometric analysis, runoff, remote sensing and GIS, SCS - method
-
Effect of variation of plastic hinge length on the results of non linear anal...eSAT Journals
Abstract The nonlinear Static procedure also well known as pushover analysis is method where in monotonically increasing loads are applied to the structure till the structure is unable to resist any further load. It is a popular tool for seismic performance evaluation of existing and new structures. In literature lot of research has been carried out on conventional pushover analysis and after knowing deficiency efforts have been made to improve it. But actual test results to verify the analytically obtained pushover results are rarely available. It has been found that some amount of variation is always expected to exist in seismic demand prediction of pushover analysis. Initial study is carried out by considering user defined hinge properties and default hinge length. Attempt is being made to assess the variation of pushover analysis results by considering user defined hinge properties and various hinge length formulations available in literature and results compared with experimentally obtained results based on test carried out on a G+2 storied RCC framed structure. For the present study two geometric models viz bare frame and rigid frame model is considered and it is found that the results of pushover analysis are very sensitive to geometric model and hinge length adopted. Keywords: Pushover analysis, Base shear, Displacement, hinge length, moment curvature analysis
Effect of use of recycled materials on indirect tensile strength of asphalt c...eSAT Journals
Abstract
Depletion of natural resources and aggregate quarries for the road construction is a serious problem to procure materials. Hence
recycling or reuse of material is beneficial. On emphasizing development in sustainable construction in the present era, recycling of
asphalt pavements is one of the effective and proven rehabilitation processes. For the laboratory investigations reclaimed asphalt
pavement (RAP) from NH-4 and crumb rubber modified binder (CRMB-55) was used. Foundry waste was used as a replacement to
conventional filler. Laboratory tests were conducted on asphalt concrete mixes with 30, 40, 50, and 60 percent replacement with RAP.
These test results were compared with conventional mixes and asphalt concrete mixes with complete binder extracted RAP
aggregates. Mix design was carried out by Marshall Method. The Marshall Tests indicated highest stability values for asphalt
concrete (AC) mixes with 60% RAP. The optimum binder content (OBC) decreased with increased in RAP in AC mixes. The Indirect
Tensile Strength (ITS) for AC mixes with RAP also was found to be higher when compared to conventional AC mixes at 300C.
Keywords: Reclaimed asphalt pavement, Foundry waste, Recycling, Marshall Stability, Indirect tensile strength.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Immunizing Image Classifiers Against Localized Adversary Attacks
Effect of admixtures on shrinkage properties in self compacting concrete
1. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 05 Issue: 02 | Feb-2016, Available @ http://www.ijret.org 292
EFFECT OF ADMIXTURES ON SHRINKAGE PROPERTIES IN SELF
COMPACTING CONCRETE
Saurav Kar1
, Shreyasee Sulakshna Sanjay2
1,2
M. Tech Student, School of Civil Engineering. KIIT University, Bhubaneswar, Odisha, India
1
sauravrafa20@gmail.com
2
sulakshnasanjay@gmail.com
Abstract
With the rapid advancement in concrete technology, demand for sustainable building materials has increased manifold in last few
decades. High strength concrete such as Self compacting concrete (SCC), also known as Self consolidated concrete, is considered
one of the finest and highly modified concrete material. SCC represents a major evolution in the building industry. The increased
use of SCC for construction and repair purposes lies in the fact that it is semi-flowable in nature and possess several advantages
such as environmental, human, technological and economical. This paper mainly focuses on the effect of various shrinkage
properties such as drying shrinkage, autogenous shrinkage and plastic shrinkage on performance of SCC. Detailed literature
review suggests that early age shrinkage in SCC has been a major setback in attaining it’s desired strength. Expansive cracking
and capillary tension are considered as two main phenomena behind shrinkage in SCC. It is found out that factors like lower
water/cement ratio or decreasing limestone filler/cement ratio leads to reduction in autogenous shrinkage. It is considered that
cracks are one of the pivotal reasons behind the poor durability of concrete as they help in entering hazardous fluids. Hence
cracks causes specific problems like plastic shrinkage. The effect of shrinkage reducing admixtures (SRA) on SCC was observed
to be positive. SRA along with paraffin based curing compounds helps in reducing cracks. It was observed from rheological tests
conducted on concrete as well as fresh SCC that, as far as drying shrinkage is concerned usage of SRA was found out to be
effective while hydrophobizing admixtures tends to be useless. Along with addition of such admixtures, limestone fines in SCC
mixes shows a reduction in autogenous shrinkage in SCC as compared to normal vibrated concrete (NVC). More importantly
results show that total shrinkage in SCC mixed with limestone filler is slightly higher (not >9.2%) than in NVC, while SCC made
with viscous Modifying Agents (VMA) shows 7.7% less shrinkage than in NVC, due to lower autogenous and drying shrinkage.
Keywords: Admixtures, Capillary Tension, Cement/Binder Ratio, Cracking, Shrinkage, Viscous Modifying Agents.
--------------------------------------------------------------------***----------------------------------------------------------------------
1. INTRODUCTION
Self compacting concrete (SCC) is an innovative type of
concrete developed in Japan. SCC does not require manual
compaction and has enough mobility without aggregate
segregation if dropped from a specified height. It has the
filling capacity and the necessary fluidity required to flow
through congested reinforcement detailing without
sedimentation[1]. Owing to the fact that it does not require
vibration to compact, it is very helpful in reducing the
concrete placing costs, enhancement of working conditions
and prevention of health hazards resulting from
vibrations[2].
The mix proportioning and design of SCC needs to be
highly precise so that it is able to achieve appropriate
workability and enough mobility to flow under its own
weight without segregation. This brings us to the
disadvantages presented by SCC, particularly a higher
shrinkage tendency as compared to normally vibrated
concrete (NVC) also known as ordinary concrete (OC)[3].
Since shrinkage tends to present serviceability defects like
cracking which may result in greater deformations than
acceptable, it is a very important aspect to be researched and
analyzed before standards are prepared. Usually shrinkage
cracking is observed during the early stages of
hydration[4][5]. There are mainly three types of shrinkages
usually presented by SCC:-autogenous shrinkage
(deformation of concrete without exchange of humidity with
the surroundings), drying shrinkage (deformation of
concrete due to humidity exchange between the porous
structure and the surroundings) and plastic shrinkage[6].
Existing studies show that autogenous shrinkage of SCC
happens to be lower than that of NVC whereas drying
shrinkage is more significant for SCC than NVC. Generally
proper curing is recommended to enhance shrinkage
reducing effects along with chemical and mineral
admixtures in definite proportions. Shrinkage reducing
admixtures (SRA) have been found to be highly effective in
counteracting shrinkage as it seems to reduce the surface
tension of water in the capillary pores[6][2].
2. BEHAVIOR OF SCC
It is a well known fact that SCC can be used in slip form
constructions such as slip form paving, owing to its self
leveling, self flowing, and self consolidating nature [7]. Due
to this ease SCC can be applied in smooth pavement
construction with a high rate of production [8][14]. The
slump value of this concrete generally varies from 254-330
mm, or to be more precise 450-750 mm as in conventional
SCC or semi-flowable SCC (SFSCC).As earlier stated
2. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 05 Issue: 02 | Feb-2016, Available @ http://www.ijret.org 293
autogenous shrinkage is a common factor concerning
concrete, researchers have found out lower values of
autogenous shrinkage in normal or ordinary concrete (CC)
with values lower than 100µ strain. Normal concrete
(bearing w/c ratio higher than 0.40) usually shows such
results [9].
Scientists and researchers all over the world have proposed
higher shrinkage for SCC for precast and prestressed
concrete structures. Many investigations on SCC show that
even though mechanical strength is superior to those of CC
(Conventional Concrete),shrinkage properties remain a
major drawback[10][27]. Shrinkage in SCC and OC were
obtained 4% and 6% higher ACI 2009R (1997)[11]. The
consolidation properties of SFSCC (Self Flowable SCC)
were improved with the addition of chemical admixtures
and fine materials. Along with the examining of the
combined effects of drying shrinkage, fracture properties,
creep and cracking potentials on SCC, few studies have also
examined the free and restrained drying shrinkage
properties, mechanical, fracture properties and creep
coefficient in SFSCC mixes. The results were compared
with conventional concrete mixes [12]. Experiments
conducted under restrained conditions reveal that the
cracking time of SFSCC mixes varied from 8-13 days,
whereas CC mixes did not show any cracking till 28 days
exposed to drying conditions [12]. Nowadays there are
many methods to determine early shrinkage in concrete.
Among them are RRTM (Restrained Ring Test Method)
introduced by Carlson and Reading [13]. Wiegrink,
Marikunte and Shah applied the same technology to find out
the shrinkage cracking in high strength concrete [14].Further
studies on drying and chemical shrinkage shows that volume
of hardened concrete decreases with time. Tensile stresses
develop in concrete as volume expansion is hindered. Hence
structural members such as slabs and pavements are more
prone to cracking. According to some researchers shrinkage
in SCC is considered almost equal to OC (Ordinary
Concrete) [15], while on the other hand international
database shows that shrinkage in SCC is 10-15% higher than
OC [16]. Knowing the fact that cracking in concrete occurs
when it reaches the ultimate value of tensile strength
(cracking resistance), according to Weiss and Berke [17],
the cracking potential can be decreased by two methods :
a.)Either by reducing the magnitude of stress development -
due to high deformation at later ages (due to drying
shrinkage) or b.)Decreasing the rate of stress development-
when stress development is higher than cracking resistance
at early ages while cracking resistance is higher than stress
development at later ages.
3. EFFECT OF ADDITIVE FILLERS ON
SHRINKAGE PROPERTIES IN SCC
Even though various modes of shrinkages in SCC are there,
basically there are two important shrinkage properties-
autogenous shrinkage and drying shrinkage. Autogenous
shrinkage basically refers to the deformation of concrete
during its hydration process in adiabatic conditions, without
allowing the exchange of temperature with the external
environment [5]. Lower content of water cement ratio (w/c)
conjugated with higher binder content leads to greater
autogenous and drying shrinkage in structural detailing. This
is because shrinkage is found to increase with the
application of finely ground supplementary cementitious
materials and filler employed in SCC [18]. Some standards
such as ASTM C33, ASTM C989, EN-206 or EN-12620
specifies of Granulated Blast Furnace Slag (GBFS) can be
used as an aggregate. Many researchers have experimented
and obtained that replacing Granulated Blast Furnace Slag
(GBFS) in place of sand has increased compressive strength
in concrete. Scandiuzzi and Batttagin[19] obtained better
long term strength due to hydraulicity of slag. While on the
contrary Topcu and Bilir[20] have pointed out lower
compressive strength, flexural strength and modulus of
elasticity due to the high porosity of mixtures and reduced
shrinkage in concrete.
When aggregates are partly replaced with slag having
hydraulic capacity, it was found that concretes are
susceptible to higher shrinkage because of volume reduction
in cementitious materials(which occur during hydration-
chemical shrinkage). It is well known that lower the w/c
ratio greater is the shrinkage, when the water/binder ratio
was kept well below 0.4 [21].Certain detailed studies show
that only GBFS is not solely responsible in producing higher
shrinkage[22].This phenomenon can be well explained as
use of reaction with GBFS results in a C-S-H phase which
means more tightly compacted pore networks. Arenallo et
al.[23]have depicted out that packed dense slag-paste
interfacial zone occurs because of blast furnace slag
reactions[24].
As far as autogenous shrinkage is concerned, shrinkage
strain and thermal strain are produced from the heat
generated during the hydration process. Results obtained in
favor of autogenous shrinkage are in accordance with other
studies [25][26]. As the concrete specimen lose water and
attain a constant equilibrium with outer environment, drying
shrinkage reduces and attains a constant value. In the
meantime autogenous shrinkage process goes on. With the
passage of time (autogenous shrinkage /total shrinkage) ratio
increases until it reaches a value of 68%-78%. Some
scientists[27][28]suggests that only increasing the quantity
of limestone fillers and keeping water/cement ratio constant,
have minor effect on autogenous shrinkage. Fig.1 shows the
variation of autogenous shrinkage with time.
Drying shrinkage cannot be directly measured. Few
scientists have suggested that drying shrinkage can be
obtained by subtracting autogenous shrinkage from total
shrinkage, as recorded in Fig.2. Fig.3. shows higher the slag
content, greater is the total shrinkage.
3. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 05 Issue: 02 | Feb-2016, Available @ http://www.ijret.org 294
Fig-1: Autogenous Shrinkage vs. Time (days) [40].
Fig-2: Drying Shrinkage vs. Time (days)[40].
Fig-3: Total Shrinkage vs. Time (days)[40].
Higher fines and cement content and a higher paste volume
are used in SCC than NVC (Normal Vibrated Concrete).
Higher the paste volume, greater is the shrinkage [5].
However it should be noted that only significant increase in
paste volume will not increase shrinkage, since other factors
are also concerned like capillary pressure [29]. Shrinkage in
SCC is retarded under the effect of many external additive
fillers like silica fumes [30], flyash and limestone fillers.
Similar to his previous works, Valcunde et al.[31]has also
conducted experimental investigations to determine
autogenous shrinkage in SCC with the application of
limestone fillers. The w/c ratio of the concrete mix kept well
around 0.6.
In the experiment conducted [31], shrinkage in SCC was
expected to be more than that in NVC, but things were very
different. SCC presented less shrinkage values as compared
with NVC. The reason behind this phenomenon can be
attributed to the presence of limestone fillers. The calcium
carbonate present in the limestone filler helps in
reconversion of monosulfoaluminate to ettringite, which in
turns increases the volume of hydrated phase[32]. Another
reason proposed is that limestone filler being inert acts as
normal aggregate, and hence hinders shrinkage.
4. EFFECT OF ADMIXTURES AND
SUPERPLASTICIZERS ON SHRINKAGE
As earlier mentioned, admixtures helps in retarding
shrinkage [31].To avoid risks of cracking in magnificent
concrete buildings, CaO based expansive agent had been
used in combination with SRA(Shrinkage Reducing
Agents). This chemical product is based on calcium sulpho
aluminates or CaO which reacts with water, to hinder
expansion in reinforced concrete structures. Collepardi et
al.[33]found out that CaO based expansive agent along with
the combination of SRA produced a synergetic effect. The
effect was helpful in expansion of concrete under wet curing
also. SRAs are highly effective in retarding drying,
autogenous and plastic shrinkage. The main mechanism
behind this lies in the fact that concrete walls are subjected
to lower surface tension. Usually under drying conditions,
water from the pores of concrete tends to escape out,
creating curved menisci. These curved menisci increases
surface tension on the walls of pores. Under the effect of
SRA, this effect gets highly reduced. Valeria Corinaldesi
[34]has conducted a series of experiments to determine the
advantages of using SRA in SCC. Results obtained report
that addition of SRAs have proved effective in reducing
drying shrinkage in concrete. The ultimate strain of
―REF+SRA‖ mix was almost 40% less than the reference
mix ―REF‖. Sant et al. explained the presence of SRA
caused portlandite oversaturation levels in solution. When
calcium oxide was mixed with reference mix-―REF+CaO‖,
initial expansion of 0.4mm/m reached a low value of drying
shrinkage.VMA (Viscous Modifying Agents) have also
shown a reduction in autogenous shrinkage in SCC.
5. CONCLUSIONS
In accordance to the review carried out, the following
conclusions can be drawn
1. SCC and OC (Ordinary Concrete) have almost equivalent
values of tensile strength and creep if compressive strength
is held constant.SCC showed higher values of shrinkage
than OC while elasticity modulus of SCC was negligibly
small as compared to OC.SCC showed cracking at an earlier
age as compared to OC.
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2. Autogenous shrinkage increases with decreasing
water/cement ratio or aggregate/cement ratio and decrease in
porosity.SCC has lower value of autogenous shrinkage and
higher value of drying shrinkage as compared to OC.
3. Limestone fillers reduce the initial and final setting time
in concrete. It causes a concrete block to shrink in water
because water cannot enter the finer porous structure. Use of
slag also has similar effect on the properties of SCC as it
also results in higher fines content.
4. Shrinkage in SCC can be reduced by using SRA
(Shrinkage Reducing Admixtures) and VMA (Viscous
Modifying Agents).
5. SRAs prevent shrinkage cracking by reducing the surface
tension of the pore water and limiting the development of
capillary stresses and at the same time by reducing water
evaporation from the concrete surface. It also lowers the
restraint of the concrete when expansion occurs.
6. Drying shrinkage in SCC is also reduced by addition of
SRA. SRA also happens to have other advantages like
reducing deformations due to temperature stresses and
increasing durability of concrete.
7. Higher values of paste volume and increase of water
content in SCC results in a slightly lower value of
compressive and flexural strength along with higher
shrinkage cracking.
8. Effect of mineral fillers like limestone reduces initial and
final setting times in SCC. Superplasticizers also respond
differently to various filler thereby influencing the various
properties of the given sample. However use of different
fillers does not show significant differences in the porosity
of the structure so there is not much difference in the final
autogenous shrinkage.
REFERENCES:
[1]Domone P.L. ―A review of hardened mechanical
properties of self compacting concrete‖. Cement & Concrete
Composites 29 (2007) 1–12.
[2]Lino Maia , Helena Figueiras , Sandra Nunes , Miguel
Azenha , Joaquim Figueiras . ―Influence of Shrinkage
Reducing admixtures on distinct SCC mix compositions‖.
Construction and Building Materials 35 (2012) 304–312.
[3]Philippe Turcry, Ahmed Loukili, Khalil Haidar, Gilles
Pijaudier-Cabot, and Abdeldjelil Belarbi. ―Cracking
Tendency of Self-Compacting Concrete Subjected to
Restrained Shrinkage: Experimental Study and Modeling‖.
J. Mater. Civ. Eng. 2006.18:46-54.
[4]Miguel José Oliveira, António Bettencourt Ribeiro ,
Fernando Garrido Branco ―Curing effect in the shrinkage of
a lower strength self-compacting concrete‖. Construction
and Building Materials xxx (2015) .
[5]Amjad Alrifai , Salima Aggoun , Abdelkader Kadri , Said
Kenai , El-hadj Kadri ―Paste and mortar studies on the
influence of mix design parameters on autogenous shrinkage
of self-compacting concrete‖. Construction and Building
Materials 47 (2013) 969–976 .
[6]Andreas Leemann , Peter Nygaard , Pietro Lura. ―Impact
of admixtures on the plastic shrinkage cracking of self-
compacting concrete‖. Cement & Concrete Composites 46
(2014) 1–7.
[7]Bonen, D., and Shah, S. P. (2005). ―Fresh and hardened
properties of self consolidating concrete.‖ Prog. Struct. Eng.
Mater., 7(1), 14–26.
[8]Wang, K., Shah, S. P., and Voigt, T. (2010). ―Self-
consolidating concrete for slip-form construction: Properties
and test methods.‖ The 50-year teaching and research
anniversary of Prof. Sun Wei on advances in civil
engineering materials, C. Miao, G. Ye, and H. Chen, eds.,
RILEM, Bagneux, France, 161–172.
[9]Davis, H.E., 1940. Autogenous Volume Change of
Concrete. Proceedings, 43rd Annual American Society for
Testing Materials Meeting, Atlantic City, NJ, p.1103-1113.
[10]Bissonnette, B., Pierre, P., and Pigeon, M. (1999).
―Influence of key parameters on drying shrinkage of
cementitious materials.‖ Cem. Concr. Res., 29(10), 1655–
1662.
[11]Naito, C.J., Parent, G., Brunn, G., 2006. ―Performance
of bulb-tee girders made with self-consolidating concrete‖.
PCI Journal, 51(6):72-85.
[12]Gilson Lomboy, Kejin Wang, M.ASCE, and
Chengsheng Ouyang (2011). ―Shrinkage and Fracture
properties of Self-Consolidating Concrete‖ Journal of
Materials in Civil Engineering (J. Mater. Civ. Eng.
2011.23:1514-1524).
[13]Carlson RW, Reading TJ. ―Model study of shrinkage
cracking in concrete building walls‖. ACI Struct J
1988;85(4):395–404.
[14]Wiegrink K, Marikunte S, Shah P. ―Shrinkage cracking
of high strength concrete‖. ACI Mater J 1996;93(5):409–15.
[15] Persson, P. _1999_. ―Creep, shrinkage and elastic
modulus of selfcompacting concrete.‖ Proc., 1st Int. RILEM
Symp. on Self- Compacting Concrete, Stockholm, Sweden,
239–250.
[16]Klug, Y., and Holschemacher, K. _2003_. ―Comparison
of the hardened properties of self-compacting and normal
vibrated concrete.‖ Proc. 3rd Int. RILEM Symp. on Self-
Compacting Concrete, Reykjavik, Iceland, 596–605.
[17]Weiss J, Berke N. Shrinkage reducing admixtures; in
early age cracking in cementitious systems. Report of
RILEM Technical Committee 181-EAS, Early age
shrinkage induced stresses and cracking in cementitious
systems: RILEM Publications SARL; 2002.
[18] Farhad ASLANI , Shami NEJADI. ―Shrinkage
behavior of Self Compacting Concrete‖ (2012). Aslani et al.
/ J Zhejiang Univ-Sci A (Appl Phys & Eng) 2012 13(6):407-
419. Journal of Zhejiang University-SCIENCE A (Applied
Physics & Engineering).
[19]Scandiuzzi L, Battagin AF. A ―Utilização da escória
granulada de altofornocomo agregado miúdo‖. Estudo
Técnico n_ 95. Associação Brasileira de Cimento Portland,
São Paulo; 1990.
[20]Topçu IB, Bilir T. ―Effect of non-ground-granulated
blast-furnace slag as fine aggregate on shrinkage cracking of
mortars‖. ACI Mater J 2010;107(6):545–53.
5. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 05 Issue: 02 | Feb-2016, Available @ http://www.ijret.org 296
[21]Aïtcin PC. ―Demystifying autogenous shrinkage‖.
Concr Int 1999;21(11):54 6.
[22]Saito K, Kinoshita M, Umehara H, Yoshida R.
―Properties of low-shrinkage, high strength SCC using
shrinkage-reducing admixture, blast furnace slag and
limestone aggregates‖. In: Khayat KH, Feys D, editors.
Design, production and placement of self-consolidating
concrete, RILEM Bookseries 1; 2010. p. 283–93.
[23]Arellano R, Burciaga O, Escalante JI. ―Lightweight
concretes of activated metakaolin–fly ash binders, with blast
furnace slag aggregates‖. Constr Build
Mater 2010;24:1166–75.
[24]M.Valcuende, F. Benito, C. Parra , I. Miñano.
―Shrinkage of Self compacting concrete with blast furnace
slag as fine aggregate‖. Construction and Building Materials
76 (2015) 1–9.
[25]Brooks JJ, Cabrera JG, Megat MA. ―Factors affecting
the autogenous shrinkage of silica fume high-strength
concrete‖. In: Tazawa E, editor. Autogenous shrinkage of
concrete. Taylor & Francis; 1999. p. 195–202.
[26]Valcuende M, Marco E, Parra C, Serna P. ―Influence of
limestone filler and viscosity-modifying admixture on the
shrinkage of self-compacting concrete‖. Cem Concr Res
2012;42(4):583–92
[27]Rozière E, Granger S, Turcry P, Loukili A. ―Influence
of paste volume on shrinkage cracking and fracture
properties of self-compacting concrete‖. Cem Concr
Compos 2007;29(8):626–36.
[28]Loser R, Leemann A. ―Shrinkage and restrained
shrinkage cracking of self compacting concrete compared to
conventionally vibrated concrete‖. Mater Struct
2009;42(1):71–82.
[29] G. Heirman, L. Vandewalle, D. Van Gemert,
―Influence of Mineral Additions and Chemical Admixtures
on Setting and Volumetric Autogenous Shrinkage of SCC
Equivalent- Mortars‖, in: G. De Schutter, V. Boel (Eds.),
Proceedings of 5th
international RILEM symposium on self-
compacting concrete, RILEM Publications S.A.R.L., Ghent,
2007, pp. 553–558.
[30] B. Lothenbach, G. Le Saout, E. Gallucci, K. Scrivener,
―Influence of limestone on the hydration of Portland
cements‖, Cem. Concr. Res. 38 (6) (2008) 848–860.
[31]M.Valcuende, E.Marco, C.Parra, P.Serna. ―Influence of
limestone filler and viscosity-modifying admixture on the
shrinkage of self-compacting concrete‖. Cement and
Concrete Research 42 (2012) 583–592.
[32]C. Legrand, E. Wirkin, ―Study of the strength of very
young concrete as a function of the amount of hydrates
formed — influence of superplasticizer‖, Mater. Struct. 27
(2) (1994) 106–109.
[33]Collepardi M, Borsoi A, Collepardi S, Ogoumah Olagot
JJ, Troli R. Effects of shrinkage-reducing admixture in
shrinkage compensating concrete under non wet curing
conditions. Cem Concr Compos 2005;27(6):704–8.
[34]Valeria Corinaldesi. ―Combined effect of expansive,
shrinkage reducing and hydrophobic admixtures for durable
self compacting concrete‖. Construction and Building
Materials 36 (2012) 758–764.