In order to solve the problem of volume stability failure of ultra-high strength concrete and realize high value utilization of heavy metal sludge,this paper proposed to use heavy metal sludge sintered pottery sand to replace part of river sand to prepare ultra-high strength concrete.The effects of different content and particle grade of pottery sand on the working performance,mechanical properties and shrinkage properties of ultra-high strength concrete were studied.The effect of pottery sand on the phase composition,microstructure and pore structure of ultra-high strength concrete were studied by XRD,TG-DTG,FTIR and SEM microscopic test methods.The results show that the pre-wetting heavy metal sludge sintered pottery sand has significant internal curing effect on the early stage of ultra-high strength concrete.When the curing age is 14 d,compared with the reference group,the autogenous shrinkage of ultra-high strength concrete with medium sand is reduced by 11.0％～27.6％,and the flexural strength is increased by 13.5％when the content of pottery sand is 20％(mass fraction).The incorporation of pottery sand can accelerate the early hydration reaction of ultra-high strength concrete,generate more hydration products,and increase the compactness of structure.However,the pre-wetting heavy metal sludge sintered pottery sand will adversely affect the strength of ultra-high strength concrete,and its content and particle grade should be controlled.
关键词
超高强混凝土/重金属污泥/陶砂/内养护/自收缩/微观特征
Key words
ultra-high strength concrete/heavy metal sludge/pottery sand/internal curing/autogenous shrinkage/microscopic characteristic
维普
万方数据