The expansive clays are extremely sensitive to the slight moisture alteration,exhibiting sequentially volume change.Uneven settlement of the buildings and infrastructures underlying expansive soil is a critical challe...The expansive clays are extremely sensitive to the slight moisture alteration,exhibiting sequentially volume change.Uneven settlement of the buildings and infrastructures underlying expansive soil is a critical challenge that geotechnical engineers have to deal with.Therefore,the objective of this study is to assess the alteration in the compressibility behavior of expansive clay respecting partial replacement of cement by zeolite in cemented samples.For this purpose,7 and 28 d cured samples treated with 6%,8%,10%,and 12%cement addition and 0,10%,30%,50%,70%,and 90%cement replacement by zeolite were investigated through Atterberg limit and a series of one-dimensional consolidation tests to evaluate the consistency limits and compressibility alteration.The liquid limits of the soil samples indicated a decremental trend as the cement content rose.Afterward,the increase of zeolite replacement up to 30%in each specific cement content diminished liquid limit to its lowest value.Further increment of zeolite replacement increased the liquid limit of the soil-binder mixtures.The lowest plasticity index was also achieved at the 30%zeolite replacement percentage;hence,the lowest swelling potential would be resulted,concerning an indirect classification.The results of the consolidation experimentations disclosed that zeolite replacement had adverse influence on consolidation parameters of cemented samples such as compression index,swell index,coefficient of compressibility,coefficient of volume compressibility,and coefficient of consolidation after 7 d of curing whereas after 28 d of curing,the 30%zeolite-replaced samples represented the best consolidation parameters.Eventually,it can be stated that the addition of cement alongside the partial substitution of cement by zeolite can be a beneficial strategy for the geo-environmental targets of this study.展开更多
In this paper,more than 70 large-scale pullout tests were performed to evaluate the performance of an innovative composite geosynthetic strip(CGS)reinforcement in sandy backfill.The CGS reinforcement is composed of a ...In this paper,more than 70 large-scale pullout tests were performed to evaluate the performance of an innovative composite geosynthetic strip(CGS)reinforcement in sandy backfill.The CGS reinforcement is composed of a geosynthetic strip(GS)and parts of a scrap truck tire as transverse members.The experimental pullout results for the CGS reinforcement were compared with the suggested theoretical equations and ordinary reinforcements,including the GS,the steel strip(SS),and the steel strip with rib(SSR).The pullout test results show that adding three transverse members to the GS reinforcement(CGS3)with S/H?6.6(where S and H are the space and height of the transverse members,respectively)increases pullout resistance by more than 120%,170%,and 50%compared to the GS,the SS,and the SSR,respectively.This result shows that the CGS3(CGS with three transverse members)reinforcement needs at least 55.5%,63%,and 33.3%smaller length compared to the GS,the SS,and the SSR,respectively.In general,implementation of mechanically stabilized earth wall(MSEW)with the proposed strip may help geotechnical engineers prevent costly designs and solve the problem of MSEW implementation in cases where there are limitations of space.展开更多
文摘The expansive clays are extremely sensitive to the slight moisture alteration,exhibiting sequentially volume change.Uneven settlement of the buildings and infrastructures underlying expansive soil is a critical challenge that geotechnical engineers have to deal with.Therefore,the objective of this study is to assess the alteration in the compressibility behavior of expansive clay respecting partial replacement of cement by zeolite in cemented samples.For this purpose,7 and 28 d cured samples treated with 6%,8%,10%,and 12%cement addition and 0,10%,30%,50%,70%,and 90%cement replacement by zeolite were investigated through Atterberg limit and a series of one-dimensional consolidation tests to evaluate the consistency limits and compressibility alteration.The liquid limits of the soil samples indicated a decremental trend as the cement content rose.Afterward,the increase of zeolite replacement up to 30%in each specific cement content diminished liquid limit to its lowest value.Further increment of zeolite replacement increased the liquid limit of the soil-binder mixtures.The lowest plasticity index was also achieved at the 30%zeolite replacement percentage;hence,the lowest swelling potential would be resulted,concerning an indirect classification.The results of the consolidation experimentations disclosed that zeolite replacement had adverse influence on consolidation parameters of cemented samples such as compression index,swell index,coefficient of compressibility,coefficient of volume compressibility,and coefficient of consolidation after 7 d of curing whereas after 28 d of curing,the 30%zeolite-replaced samples represented the best consolidation parameters.Eventually,it can be stated that the addition of cement alongside the partial substitution of cement by zeolite can be a beneficial strategy for the geo-environmental targets of this study.
文摘In this paper,more than 70 large-scale pullout tests were performed to evaluate the performance of an innovative composite geosynthetic strip(CGS)reinforcement in sandy backfill.The CGS reinforcement is composed of a geosynthetic strip(GS)and parts of a scrap truck tire as transverse members.The experimental pullout results for the CGS reinforcement were compared with the suggested theoretical equations and ordinary reinforcements,including the GS,the steel strip(SS),and the steel strip with rib(SSR).The pullout test results show that adding three transverse members to the GS reinforcement(CGS3)with S/H?6.6(where S and H are the space and height of the transverse members,respectively)increases pullout resistance by more than 120%,170%,and 50%compared to the GS,the SS,and the SSR,respectively.This result shows that the CGS3(CGS with three transverse members)reinforcement needs at least 55.5%,63%,and 33.3%smaller length compared to the GS,the SS,and the SSR,respectively.In general,implementation of mechanically stabilized earth wall(MSEW)with the proposed strip may help geotechnical engineers prevent costly designs and solve the problem of MSEW implementation in cases where there are limitations of space.
