The existing practice of subgrade has been modified with the unique type of subgrade that can wit... more The existing practice of subgrade has been modified with the unique type of subgrade that can withstand running traffic >20msa with 90% reliability. This can be achieved by adding fly ash, stone dust and tire rubber to pavement subgrade. This modified subgrade Mix was prepared to improve the strength of subgrade. Conventional and modified subgrade pavement mixes were tested with CBR values and the resilient modulus of conventional and modified subgrade has been found as per IRC 37-2008. Plate load test has been carried out in the laboratory with the continuous loads on the subgrade and the moduli of subgrade reaction obtained finally were compared analytically using IIT Pave software. The optimal mix proportion of Modified subgrade denotes (subgrade soil with 22% Stone Dust, 4% Fly Ash and 2% Tire Rubber). The modified subgrade in flexible pavement showed an increase in bearing capacity, resilient modulus (M r) and modulus of subgrade reaction (k) which gave fruitful results with the optimum mix proportion with stone dust, fly ash and tire rubber. The usage of these materials in the construction of pavements decreases the industrial waste, minimizes the environmental pollution, decreases the pavement thickness as well as increases the pavement life.
Alumina (Al2O3) powder was synthesized by simple wet-chemical precipitation method. The phase stu... more Alumina (Al2O3) powder was synthesized by simple wet-chemical precipitation method. The phase study was done using XRD confirming the FCC phase. FTIR showed the presence of Al-O vibrations. Particle size analysis (PSA) confirmed the presence of particles in the range of 300 nm. The EDX confirmed the presence of Al and O elements in the samples only and no impurity elements. SEM exhibited the ultrafine nature of the particles. The tape casting of Al2O3 nanoparticles was carried out with suitable organic ingredients. Based on the trials, the best composition for alumina tape casting was optimized. The SEM of green alumina thin sheet resulted in good surface behaviour. Optimized composition may be used for fabricating thin Al2O3 based electrical components for application in electronics industry.
The major earthquake occurred in India (Bhuj 2001) indicates that the collapse of masonry buildin... more The major earthquake occurred in India (Bhuj 2001) indicates that the collapse of masonry buildings are mostly because of in- plane and out-of-plane behaviour, especially because of the inadequate junctions between the perpendicular walls. It is necessary to understand the behavior of masonry wall under lateral load so that proper mitigation measures can be applied to existing buildings for retrofitting and to set the design guidelines for the new construction. An experimental research has been carried out on scaled masonry wall panels for in-plane loading. Several series of unreinforced masonry walls (C1-C6) of clay brick panel and (F1 – F6) of flyash brick panel of size 1m x1m x 0.23m were constructed with cement flyash mortar and were tested under constant vertical load and lateral in-plane load. Later, strengthened masonry walls with reinforced woven wire mesh were tested with the same geometry and boundary conditions. The force-displacement curves were obtained for the brick pa...
The major earthquake occurred in India (Bhuj 2001) indicates that the collapse of masonry buildin... more The major earthquake occurred in India (Bhuj 2001) indicates that the collapse of masonry buildings are mostly because of in- plane and out-of-plane behaviour, especially because of the inadequate junctions between the perpendicular walls. It is necessary to understand the behavior of masonry wall under lateral load so that proper mitigation measures can be applied to existing buildings for retrofitting and to set the design guidelines for the new construction. An experimental research has been carried out on scaled masonry wall panels for in-plane loading. Several series of unreinforced masonry walls (C1-C6) of clay brick panel and (F1 – F6) of flyash brick panel of size 1m x1m x 0.23m were constructed with cement flyash mortar and were tested under constant vertical load and lateral in-plane load. Later, strengthened masonry walls with reinforced woven wire mesh were tested with the same geometry and boundary conditions. The force-displacement curves were obtained for the brick pa...
Nanostructured electrode materials have illustrated predominant electrochemical properties in pro... more Nanostructured electrode materials have illustrated predominant electrochemical properties in producing high-performance supercapacitors. Perovskite based nanostructures with formula ABO3 have received broad consideration due to their excellent physical and chemical characteristics such as electrically active structure, electronic conductivity, ionic conductivity, supermagnetic, photocatalytic, thermoelectric, and dielectric properties, etc. Hence, perovksite based nano-structured materials are supposed to be promising, fascinating electrode materials for designing supercapacitors with high energy storage performance. In this review article, the recent progress and advances in designing perovskite based nanostructured electrode materials is discussed, which can provide as a guideline for the next generation of supercapacitor electrode design.
This paper presents the experimental investigations of small burnt clay brick masonry samples. Th... more This paper presents the experimental investigations of small burnt clay brick masonry samples. The shear bond strength has been obtained from 3 brick triplets. An experimental programme examining the bond strength of mortar-unit joints was therefore carried out, using mortars with and without pozzolans. It has been found that the strength and deformation characteristics of masonry constituents obtained from these tests are more representative of the actual composite behaviour of masonry. But, there is a need for energy efficient and environment friendly alternative materials for masonry. Fly ash blocks or bricks represent one such alternative for masonry applications. The deformation characteristics of individual brick and mortar have been determined and found to be different due to the composite action between the brick and mortar joint. The research quantified the differences in bond strengths achieved with various mortar/masonry unit combinations.
Stone columns are extensively used to improve the bearing capacity of poor ground and reduce the ... more Stone columns are extensively used to improve the bearing capacity of poor ground and reduce the settlement of structures built on them. A stone column is one of the soil stabilization methods that is used to increase strength, decrease the compressibility of soft and loose fine graded soils, accelerate a consolidation effect and reduce the liquefaction potential of soils. They are mainly used for stabilization soft soil such as soft clays, silts and silt-sands. It is believed that this method was used first in France in 1830s. This method is in wide range of use especially in Europe since 1950s. The columns consist of compacted gravel or crushed stone arranged by a vibrator. This article presents a review of previous studies on the performance of improving the bearing capacity of various types of soils, with different material and other parameters.
International Journal of Civil and Structural Engineering, 2012
Masonry buildings are brittle in nature and one of the most vulnerable among the different types ... more Masonry buildings are brittle in nature and one of the most vulnerable among the different types of structural buildings under strong earthquake shaking. Horizontal loads, induced by earthquake causes severe in-plane and out of plane forces in wall. A wall topples down easily if pushed horizontally at the top in a direction perpendicular to its plane (out - of plane), but offers much greater resistance if pushed along its length (in-plane). The lateral load resistance of masonry buildings is mainly due to in-plane shear resistance of the masonry elements/piers. Therefore detailed investigation on the in-plane shear behaviour of masonry thus becomes necessary. Earthquake performance of a masonry wall is very sensitive to the properties of its constituents, namely masonry units and mortar. The shearing strength of masonry mainly depends upon the bond or adhesion at the contact surface between the masonry unit and the mortar. Thus, it is very important to improve the shear behaviour of...
Journal of Civil and Environmental Engineering, 2020
Carbon dioxide is one of the major air pollutants into the atmosphere. Carbon dioxide is emitted ... more Carbon dioxide is one of the major air pollutants into the atmosphere. Carbon dioxide is emitted more into the atmosphere because of combustion of fossil fuels (coal, oil and natural gas) in cement production industry and many other industries and emissions from traffic congestions. Carbon-dioxide pollutes the air and the air pollution is the major threat faced by the present generation. Hence, there is a need to have an eco-friendly concrete which can absorb the carbon-dioxide from the atmosphere and reduces the air pollution. Therefore, a study has been carried out on the zeolite concrete for the enhancement of the mechanical properties and on the absorption of carbon sequestration in to the zeolite concrete.
International journal of engineering research and technology, 2013
Concrete is a widely used as a construction material in civil Engineering field for various types... more Concrete is a widely used as a construction material in civil Engineering field for various types of structures due to its durability. For a long time it was considered to be very durable material requiring a little or no maintenance. Many environmental factors are known significantly the durability of reinforced concrete structures. The climate change due to global warming, one of non Portland cements the greatest environmental issues has become a major concern during the past decade. Main reason of global warming is because of caused by the emission of greenhouse gases, such as CO2, to the atmosphere by more human activities. Among the greenhouse gases, CO2 is responsible for contributes about 65% of global warming. The cement manufacturing industry is responsible for nearly 6% of all CO2 emissions, because the production of one ton ordinary of Portland cement approximately emits one ton of CO2 into the atmosphere. Fly ash based Geopolymer is prepared from low calcium fly ash by activation with a mixture of alkaline liquids (Sodium Hydroxide and Sodium Silicate solution). Fly ash is a byproduct of Thermal Power Plant. A combination of sodium silicate solution and sodium hydroxide solution was chosen as the alkaline liquid. Sodium-based alkaline solutions were chosen because they were cheaper than Potassium-based solutions. The use of Copper Slag (CS) in concrete provides environmental as well as economic benefits for all industries, mainly in areas where a large amount of CS is produced. In this paper we deals with the fresh and hardened properties of the fly ash based geopolymer concrete with copper slag. Preliminary Investigation physical and chemical properties of various materials as cement, fine aggregate, coarse aggregate, copper slag. Fly ash is tested and the properties are compared with each other. Fresh and hardened properties of conventional concrete and blended cement concrete are tested and compared. Conclusion of this paper will be based on the test results and comparative statement.
This paper provides a broad overview of some of the key factors in the design monopile foundation... more This paper provides a broad overview of some of the key factors in the design monopile foundation for fixed offshore structure. During the last years, offshore wind turbine structures were reported to settle on the monopile structure and the resulting force flow in the structures was different to that intended at the design stage. A joint industry project was therefore carried out by Det Nordce Veritas (DNV) [1] to investigate the structural capacity of these connections from autumn 2009 to January 2011. It was found that the axial capacity of the grouted connections is a more sensitive function to the diameter and surface tolerances than that accounted for in existing design standards.
Large number of innovative alternate building materials and low cost construction techniques deve... more Large number of innovative alternate building materials and low cost construction techniques developed through intensive research efforts during last three to four decades satisfies functional as well as specification requirements of conventional materials/techniques and provide ...
Brickwork is a composite material with bricks as the building units and the mortar as the jointin... more Brickwork is a composite material with bricks as the building units and the mortar as the jointing material. When this two element combined to form a brickwork unit, the properties of the materials influences the strength of the brickwork. Short prisms have been tested under axial compressive load using two types of masonry units: clay brick and flyash brick using flyash cement mortar. The brick masonry is reinforced with woven wire mesh at the alternate bed joint and tested for its axial strength and elastic modulus of the prisms specimens. They confirm that masonry prisms may be used for determining the basic compressive strength. Areas needing further investigation include the effect of moisture on the strength of brick masonry and the strength of eccentrically loaded brick work. In the present research, design strength was determined.
The existing practice of subgrade has been modified with the unique type of subgrade that can wit... more The existing practice of subgrade has been modified with the unique type of subgrade that can withstand running traffic >20msa with 90% reliability. This can be achieved by adding fly ash, stone dust and tire rubber to pavement subgrade. This modified subgrade Mix was prepared to improve the strength of subgrade. Conventional and modified subgrade pavement mixes were tested with CBR values and the resilient modulus of conventional and modified subgrade has been found as per IRC 37-2008. Plate load test has been carried out in the laboratory with the continuous loads on the subgrade and the moduli of subgrade reaction obtained finally were compared analytically using IIT Pave software. The optimal mix proportion of Modified subgrade denotes (subgrade soil with 22% Stone Dust, 4% Fly Ash and 2% Tire Rubber). The modified subgrade in flexible pavement showed an increase in bearing capacity, resilient modulus (M r) and modulus of subgrade reaction (k) which gave fruitful results with the optimum mix proportion with stone dust, fly ash and tire rubber. The usage of these materials in the construction of pavements decreases the industrial waste, minimizes the environmental pollution, decreases the pavement thickness as well as increases the pavement life.
Alumina (Al2O3) powder was synthesized by simple wet-chemical precipitation method. The phase stu... more Alumina (Al2O3) powder was synthesized by simple wet-chemical precipitation method. The phase study was done using XRD confirming the FCC phase. FTIR showed the presence of Al-O vibrations. Particle size analysis (PSA) confirmed the presence of particles in the range of 300 nm. The EDX confirmed the presence of Al and O elements in the samples only and no impurity elements. SEM exhibited the ultrafine nature of the particles. The tape casting of Al2O3 nanoparticles was carried out with suitable organic ingredients. Based on the trials, the best composition for alumina tape casting was optimized. The SEM of green alumina thin sheet resulted in good surface behaviour. Optimized composition may be used for fabricating thin Al2O3 based electrical components for application in electronics industry.
The major earthquake occurred in India (Bhuj 2001) indicates that the collapse of masonry buildin... more The major earthquake occurred in India (Bhuj 2001) indicates that the collapse of masonry buildings are mostly because of in- plane and out-of-plane behaviour, especially because of the inadequate junctions between the perpendicular walls. It is necessary to understand the behavior of masonry wall under lateral load so that proper mitigation measures can be applied to existing buildings for retrofitting and to set the design guidelines for the new construction. An experimental research has been carried out on scaled masonry wall panels for in-plane loading. Several series of unreinforced masonry walls (C1-C6) of clay brick panel and (F1 – F6) of flyash brick panel of size 1m x1m x 0.23m were constructed with cement flyash mortar and were tested under constant vertical load and lateral in-plane load. Later, strengthened masonry walls with reinforced woven wire mesh were tested with the same geometry and boundary conditions. The force-displacement curves were obtained for the brick pa...
The major earthquake occurred in India (Bhuj 2001) indicates that the collapse of masonry buildin... more The major earthquake occurred in India (Bhuj 2001) indicates that the collapse of masonry buildings are mostly because of in- plane and out-of-plane behaviour, especially because of the inadequate junctions between the perpendicular walls. It is necessary to understand the behavior of masonry wall under lateral load so that proper mitigation measures can be applied to existing buildings for retrofitting and to set the design guidelines for the new construction. An experimental research has been carried out on scaled masonry wall panels for in-plane loading. Several series of unreinforced masonry walls (C1-C6) of clay brick panel and (F1 – F6) of flyash brick panel of size 1m x1m x 0.23m were constructed with cement flyash mortar and were tested under constant vertical load and lateral in-plane load. Later, strengthened masonry walls with reinforced woven wire mesh were tested with the same geometry and boundary conditions. The force-displacement curves were obtained for the brick pa...
Nanostructured electrode materials have illustrated predominant electrochemical properties in pro... more Nanostructured electrode materials have illustrated predominant electrochemical properties in producing high-performance supercapacitors. Perovskite based nanostructures with formula ABO3 have received broad consideration due to their excellent physical and chemical characteristics such as electrically active structure, electronic conductivity, ionic conductivity, supermagnetic, photocatalytic, thermoelectric, and dielectric properties, etc. Hence, perovksite based nano-structured materials are supposed to be promising, fascinating electrode materials for designing supercapacitors with high energy storage performance. In this review article, the recent progress and advances in designing perovskite based nanostructured electrode materials is discussed, which can provide as a guideline for the next generation of supercapacitor electrode design.
This paper presents the experimental investigations of small burnt clay brick masonry samples. Th... more This paper presents the experimental investigations of small burnt clay brick masonry samples. The shear bond strength has been obtained from 3 brick triplets. An experimental programme examining the bond strength of mortar-unit joints was therefore carried out, using mortars with and without pozzolans. It has been found that the strength and deformation characteristics of masonry constituents obtained from these tests are more representative of the actual composite behaviour of masonry. But, there is a need for energy efficient and environment friendly alternative materials for masonry. Fly ash blocks or bricks represent one such alternative for masonry applications. The deformation characteristics of individual brick and mortar have been determined and found to be different due to the composite action between the brick and mortar joint. The research quantified the differences in bond strengths achieved with various mortar/masonry unit combinations.
Stone columns are extensively used to improve the bearing capacity of poor ground and reduce the ... more Stone columns are extensively used to improve the bearing capacity of poor ground and reduce the settlement of structures built on them. A stone column is one of the soil stabilization methods that is used to increase strength, decrease the compressibility of soft and loose fine graded soils, accelerate a consolidation effect and reduce the liquefaction potential of soils. They are mainly used for stabilization soft soil such as soft clays, silts and silt-sands. It is believed that this method was used first in France in 1830s. This method is in wide range of use especially in Europe since 1950s. The columns consist of compacted gravel or crushed stone arranged by a vibrator. This article presents a review of previous studies on the performance of improving the bearing capacity of various types of soils, with different material and other parameters.
International Journal of Civil and Structural Engineering, 2012
Masonry buildings are brittle in nature and one of the most vulnerable among the different types ... more Masonry buildings are brittle in nature and one of the most vulnerable among the different types of structural buildings under strong earthquake shaking. Horizontal loads, induced by earthquake causes severe in-plane and out of plane forces in wall. A wall topples down easily if pushed horizontally at the top in a direction perpendicular to its plane (out - of plane), but offers much greater resistance if pushed along its length (in-plane). The lateral load resistance of masonry buildings is mainly due to in-plane shear resistance of the masonry elements/piers. Therefore detailed investigation on the in-plane shear behaviour of masonry thus becomes necessary. Earthquake performance of a masonry wall is very sensitive to the properties of its constituents, namely masonry units and mortar. The shearing strength of masonry mainly depends upon the bond or adhesion at the contact surface between the masonry unit and the mortar. Thus, it is very important to improve the shear behaviour of...
Journal of Civil and Environmental Engineering, 2020
Carbon dioxide is one of the major air pollutants into the atmosphere. Carbon dioxide is emitted ... more Carbon dioxide is one of the major air pollutants into the atmosphere. Carbon dioxide is emitted more into the atmosphere because of combustion of fossil fuels (coal, oil and natural gas) in cement production industry and many other industries and emissions from traffic congestions. Carbon-dioxide pollutes the air and the air pollution is the major threat faced by the present generation. Hence, there is a need to have an eco-friendly concrete which can absorb the carbon-dioxide from the atmosphere and reduces the air pollution. Therefore, a study has been carried out on the zeolite concrete for the enhancement of the mechanical properties and on the absorption of carbon sequestration in to the zeolite concrete.
International journal of engineering research and technology, 2013
Concrete is a widely used as a construction material in civil Engineering field for various types... more Concrete is a widely used as a construction material in civil Engineering field for various types of structures due to its durability. For a long time it was considered to be very durable material requiring a little or no maintenance. Many environmental factors are known significantly the durability of reinforced concrete structures. The climate change due to global warming, one of non Portland cements the greatest environmental issues has become a major concern during the past decade. Main reason of global warming is because of caused by the emission of greenhouse gases, such as CO2, to the atmosphere by more human activities. Among the greenhouse gases, CO2 is responsible for contributes about 65% of global warming. The cement manufacturing industry is responsible for nearly 6% of all CO2 emissions, because the production of one ton ordinary of Portland cement approximately emits one ton of CO2 into the atmosphere. Fly ash based Geopolymer is prepared from low calcium fly ash by activation with a mixture of alkaline liquids (Sodium Hydroxide and Sodium Silicate solution). Fly ash is a byproduct of Thermal Power Plant. A combination of sodium silicate solution and sodium hydroxide solution was chosen as the alkaline liquid. Sodium-based alkaline solutions were chosen because they were cheaper than Potassium-based solutions. The use of Copper Slag (CS) in concrete provides environmental as well as economic benefits for all industries, mainly in areas where a large amount of CS is produced. In this paper we deals with the fresh and hardened properties of the fly ash based geopolymer concrete with copper slag. Preliminary Investigation physical and chemical properties of various materials as cement, fine aggregate, coarse aggregate, copper slag. Fly ash is tested and the properties are compared with each other. Fresh and hardened properties of conventional concrete and blended cement concrete are tested and compared. Conclusion of this paper will be based on the test results and comparative statement.
This paper provides a broad overview of some of the key factors in the design monopile foundation... more This paper provides a broad overview of some of the key factors in the design monopile foundation for fixed offshore structure. During the last years, offshore wind turbine structures were reported to settle on the monopile structure and the resulting force flow in the structures was different to that intended at the design stage. A joint industry project was therefore carried out by Det Nordce Veritas (DNV) [1] to investigate the structural capacity of these connections from autumn 2009 to January 2011. It was found that the axial capacity of the grouted connections is a more sensitive function to the diameter and surface tolerances than that accounted for in existing design standards.
Large number of innovative alternate building materials and low cost construction techniques deve... more Large number of innovative alternate building materials and low cost construction techniques developed through intensive research efforts during last three to four decades satisfies functional as well as specification requirements of conventional materials/techniques and provide ...
Brickwork is a composite material with bricks as the building units and the mortar as the jointin... more Brickwork is a composite material with bricks as the building units and the mortar as the jointing material. When this two element combined to form a brickwork unit, the properties of the materials influences the strength of the brickwork. Short prisms have been tested under axial compressive load using two types of masonry units: clay brick and flyash brick using flyash cement mortar. The brick masonry is reinforced with woven wire mesh at the alternate bed joint and tested for its axial strength and elastic modulus of the prisms specimens. They confirm that masonry prisms may be used for determining the basic compressive strength. Areas needing further investigation include the effect of moisture on the strength of brick masonry and the strength of eccentrically loaded brick work. In the present research, design strength was determined.
Uploads
Papers by Freeda Christy