In this paper,the punching shear performance of 8 steel fiber reinforced recycled coarse aggregate concrete(SFRCAC)two-way slabs with a size of 1800 mm×1800 mm×150 mm was studied under local concentric load....In this paper,the punching shear performance of 8 steel fiber reinforced recycled coarse aggregate concrete(SFRCAC)two-way slabs with a size of 1800 mm×1800 mm×150 mm was studied under local concentric load.The effects of RCA replacement ratio(rg)and SF volume fraction(Vf)on the punching shear performance of SFRCAC two-way slabs were investigated.Digital Image Correlation(DIC)measurement and Acoustic Emission(AE)technique were introduced to collect pictures and relevant data during the punching shear test.The test results show that the SFRCAC two-way slab mainly exhibits punching shear failure and flexure failure under local concentric load.The punching shear failure space area of SFRCAC two-way slab has no obvious change with increasing rg,however,show a gradual increase trend with increasing Vf.Both of the punching shear ultimate bearing capacity(Pu)and its deflection of SFRCAC two-way slab decrease with increasing rg and increase with increasing Vf,respectively.Finally,through the regression analysis of the results from this study and the data collected from related literature,the influence of rg and Vf on the Pu of two-way slabs were obtained,and the equations in GB 50010-2010,ACI 318-19,and Eurocode 2 Codes were amended,respectively.Furthermore,the amended equations were all applicable to predicted the ultimate bearing capacity of the ordinary concrete two-way slab,RCAC two-way slab,SFRC two-way slab,and SFRCAC two-way slab.展开更多
To promote the application of green renewable materials in concrete composite slabs(CCSs)and study the flexural behavior of CCSs with different shapes,the bending performances of three CCSs with a SFRRAC base plate,on...To promote the application of green renewable materials in concrete composite slabs(CCSs)and study the flexural behavior of CCSs with different shapes,the bending performances of three CCSs with a SFRRAC base plate,one cast-in-site concrete slab of ordinary concrete and one CCS of ordinary concrete by steel bar truss(as recommended in the technical specification for precast concrete structures in Chinese)were compared through experiments.The carrying capacity,flexural behaviour and bi-directional mechanical properties of the specimens were systematically analyzed from the failure modes,load-deflection curves,load-bar strain curves,load-slip curves and crack distributions.Results show that the bending failure process of CCSs with a SFRRAC base plate is similar to that of the cast-in-site concrete slab of ordinary concrete and CCS of ordinary concrete by steel bar truss,as all of them went through the plastic phase,elastic plastic phase and failure phase with fully developed cracks and deflection.No sudden breakage or horizontal cracking of the connecting interface between the base plate and concrete topping was observed.The shape of the base plate has a major impact on the bearing capacity of the CCS with the SFRRAC base plate.When calculating the ultimate bearing capacity with the plastic yield line theory,the influence of the base plate shape on the plastic yield line position should be taken into account.展开更多
基金the financial support of National Natural Science Foundation of China(Grant No.51978629)。
文摘In this paper,the punching shear performance of 8 steel fiber reinforced recycled coarse aggregate concrete(SFRCAC)two-way slabs with a size of 1800 mm×1800 mm×150 mm was studied under local concentric load.The effects of RCA replacement ratio(rg)and SF volume fraction(Vf)on the punching shear performance of SFRCAC two-way slabs were investigated.Digital Image Correlation(DIC)measurement and Acoustic Emission(AE)technique were introduced to collect pictures and relevant data during the punching shear test.The test results show that the SFRCAC two-way slab mainly exhibits punching shear failure and flexure failure under local concentric load.The punching shear failure space area of SFRCAC two-way slab has no obvious change with increasing rg,however,show a gradual increase trend with increasing Vf.Both of the punching shear ultimate bearing capacity(Pu)and its deflection of SFRCAC two-way slab decrease with increasing rg and increase with increasing Vf,respectively.Finally,through the regression analysis of the results from this study and the data collected from related literature,the influence of rg and Vf on the Pu of two-way slabs were obtained,and the equations in GB 50010-2010,ACI 318-19,and Eurocode 2 Codes were amended,respectively.Furthermore,the amended equations were all applicable to predicted the ultimate bearing capacity of the ordinary concrete two-way slab,RCAC two-way slab,SFRC two-way slab,and SFRCAC two-way slab.
基金The National Natural Science Foundation of China(No.51578446).
文摘To promote the application of green renewable materials in concrete composite slabs(CCSs)and study the flexural behavior of CCSs with different shapes,the bending performances of three CCSs with a SFRRAC base plate,one cast-in-site concrete slab of ordinary concrete and one CCS of ordinary concrete by steel bar truss(as recommended in the technical specification for precast concrete structures in Chinese)were compared through experiments.The carrying capacity,flexural behaviour and bi-directional mechanical properties of the specimens were systematically analyzed from the failure modes,load-deflection curves,load-bar strain curves,load-slip curves and crack distributions.Results show that the bending failure process of CCSs with a SFRRAC base plate is similar to that of the cast-in-site concrete slab of ordinary concrete and CCS of ordinary concrete by steel bar truss,as all of them went through the plastic phase,elastic plastic phase and failure phase with fully developed cracks and deflection.No sudden breakage or horizontal cracking of the connecting interface between the base plate and concrete topping was observed.The shape of the base plate has a major impact on the bearing capacity of the CCS with the SFRRAC base plate.When calculating the ultimate bearing capacity with the plastic yield line theory,the influence of the base plate shape on the plastic yield line position should be taken into account.
