In this study,the damping responses of uniform soil,equi-proportional fly ash,and local soil as a single unit were investigated.The large-strain cyclic triaxial tests were performed for the specimen compacted at the d...In this study,the damping responses of uniform soil,equi-proportional fly ash,and local soil as a single unit were investigated.The large-strain cyclic triaxial tests were performed for the specimen compacted at the desired density(95%e99%of maximum dry density).The compacted specimens were tested under the loading frequency of 0.3e1 Hz with medium confinement of 70e100 kPa.Also,the unsymmetrical behavior of the hysteresis loop was analyzed using three different damping estimation approaches,i.e.symmetric hysteresis loop(SHL),asymmetric hysteresis loop(ASHL),and the modified American Society for Testing and Materials(ASTM)method.The outcome of the study shows for fly ash,local soil,and layered soil-ash,the ASHL technique has the highest damping value,followed by ASTM and then the SHL approach.The specimens prepared under high density and subjected to high confinement show low damping values.However,the specimens tested at high frequency exhibits high damping behavior.Similarly,the damping value of fly ash determined using the SHL and ASHL methods has a similar profile and reaches a maximum at 1%shear strain value before decreasing.The composite stratified deposit exhibits more dependency on relative compaction,confining pressure,and less on loading frequency.Based on the results,it is highly recommended to use the ASHL approach,especially under large strain conditions irrespective of soil type.The maximum damping ratio of stratified deposits is always in between the damping ratio of local soil and fly ash.The damping ratio of stratified soil and local soil is slightly larger than that of the other soils,although the damping ratio of fly ash is equivalent to that of the sand and clayey soil.These results may be helpful in the accurate determination of the damping properties of the layered soil-ash system that is required in the seismic response analysis.展开更多
The focus of this study is to critically review the physiochemical and engineering properties of the fly ash and its applications in various fields.The utilization of fly ash has become a widespread area,but the amoun...The focus of this study is to critically review the physiochemical and engineering properties of the fly ash and its applications in various fields.The utilization of fly ash has become a widespread area,but the amount of utilization is still a serious issue.It has many beneficial qualities(such as pozzolanic property,fineness,spherical shape,lightweight,etc.),which enhance its properties and make it suitable for its utilization as a new construction material.For the bulk utilization of fly ash,it should be employed in the areas independent of any other parameters.So that,the disposal problem can be reduced significantly.The knowledge of its physiochemical characteristic helps in the judgment of appropriate fly ash for any particular type of work.Fly ash can be utilized in other areas such as asphalt concrete,geopolymer concrete,ground improvement,agricultural sector,roller compacted concrete,brick,etc.that will reduce the existing ashes,and also the disposal problem can be solved appreciably.The implementation of fly ash must be avoided below the natural ground water level and below 4°C temperature conditions.展开更多
文摘In this study,the damping responses of uniform soil,equi-proportional fly ash,and local soil as a single unit were investigated.The large-strain cyclic triaxial tests were performed for the specimen compacted at the desired density(95%e99%of maximum dry density).The compacted specimens were tested under the loading frequency of 0.3e1 Hz with medium confinement of 70e100 kPa.Also,the unsymmetrical behavior of the hysteresis loop was analyzed using three different damping estimation approaches,i.e.symmetric hysteresis loop(SHL),asymmetric hysteresis loop(ASHL),and the modified American Society for Testing and Materials(ASTM)method.The outcome of the study shows for fly ash,local soil,and layered soil-ash,the ASHL technique has the highest damping value,followed by ASTM and then the SHL approach.The specimens prepared under high density and subjected to high confinement show low damping values.However,the specimens tested at high frequency exhibits high damping behavior.Similarly,the damping value of fly ash determined using the SHL and ASHL methods has a similar profile and reaches a maximum at 1%shear strain value before decreasing.The composite stratified deposit exhibits more dependency on relative compaction,confining pressure,and less on loading frequency.Based on the results,it is highly recommended to use the ASHL approach,especially under large strain conditions irrespective of soil type.The maximum damping ratio of stratified deposits is always in between the damping ratio of local soil and fly ash.The damping ratio of stratified soil and local soil is slightly larger than that of the other soils,although the damping ratio of fly ash is equivalent to that of the sand and clayey soil.These results may be helpful in the accurate determination of the damping properties of the layered soil-ash system that is required in the seismic response analysis.
基金Science and Engineering Research Board(ECR/2015/000580).
文摘The focus of this study is to critically review the physiochemical and engineering properties of the fly ash and its applications in various fields.The utilization of fly ash has become a widespread area,but the amount of utilization is still a serious issue.It has many beneficial qualities(such as pozzolanic property,fineness,spherical shape,lightweight,etc.),which enhance its properties and make it suitable for its utilization as a new construction material.For the bulk utilization of fly ash,it should be employed in the areas independent of any other parameters.So that,the disposal problem can be reduced significantly.The knowledge of its physiochemical characteristic helps in the judgment of appropriate fly ash for any particular type of work.Fly ash can be utilized in other areas such as asphalt concrete,geopolymer concrete,ground improvement,agricultural sector,roller compacted concrete,brick,etc.that will reduce the existing ashes,and also the disposal problem can be solved appreciably.The implementation of fly ash must be avoided below the natural ground water level and below 4°C temperature conditions.
