Influence of coal gangue powder on mechanical and shrinkage behaviors of UHPC with calculation method of autogenous shrinkage
It aims to fabricate a low carbon,green,environmental,and economical coal gangue ultra-high performance concrete(UHPC)with excellent mechanical properties used in practical engineering,realizing a reutilization of solid waste.The tensile and compressive strengths,elastic modulus,and autogenous shrinkage stain of the UHPC with various mass substitution ratios(20％,40％,and 60％)were experimentally measured.In addition,the mechanism of coal gangue in producing UHPC was revealed,and the applicability of existing theoretical calculations for concrete autogenous shrinkage was assessed.The results indicate that high content of coal gangue powder can be used in the production of UHPC.The prism compressive strength of the UHPC with 1.5％steel fiber content exceeded 130 MPa,and its tensile strength reached 6.7 MPa.The autogenous shrinkage strain at initial setting time and finial shrinkage strain of the UHPC with 60％coal gangue powder content were reduced by 12.2％and 12.5％,respectively.The increase in volume of coal gangue powder effectively reduced the initial setting time of UHPC,accelerated the UHPC autogenous shrinkage process,and decreased the UHPC autogenous shrinkage strain.The existing concrete autogenous shrinkage calculation methods fail to reflect the effect of coal gangue powder content on the UHPC autogenous shrinkage strain and its initial setting time.Finally,based on the experimental results,a calculation method for coal gangue UHPC autogenous shrinkage was modified and proposed,and this method was effective in predicting the autogenous shrinkage behavior of coal gangue UHPC.
万方数据
维普
