关键词: 蒸养混凝土;重金属离子;抗压强度;固化;粉煤灰

Abstract: Abstact:Considering its high early strength,mold transfer speed and production efficiency,steam curing concrete has become the main preparation technology of precast concrete.The mechanical properties,ion leaching test and X ray diffraction were used to investigated the effects of zinc,chromium and copper on the mechanical properties,hydration product structure and leaching characteristics of steam curing concrete.What~ more,the effects of fly ash on solidification of heavy metal ions by steam curing concrete was also discussed.The results show that:①Zn,Cr and Cu ions reduce the compressive strength of steam curing concrete in varying degrees.When the dosage of 1％,the compressive strength decreases by 50.63％,13.23％ and 99.27％,respectively.Zn,Cr and Cu ions can not significantly change the morphology of hydration products,but can inhibit the formation and crystallization of calcium hydroxide and ettringite.②When the dosage is lower than 1％,the steam curing concrete have good solidification on Zn and Cr ions,the leaching concentration of which are less than 0.21 mg/L,but the leaching concentration of Cu ion is as high as more than 0.92 mg/L.The compressive strength of steam curing concrete added with 20％ fly ash is reduced by about 5 ～8 MPa,and the solidification of heavy metal ions can not be improved.

Key words: steam curing concrete;heavy metal ion;compressive strength;solidification;fly ash