The effect of double-doped fly ash and silica fume on the mechanical properties of mortar under ultra-low temperature environment
In this paper,the influence of fly ash and silica fume on the compressive strength,flexural strength and frost resis-tance of cement mortar after ultra-low temperature freeze-thaw cycle(-190～20 ℃)was studied under different dosage of fly ash and silica fume.The results show that the deterioration degree of cement mortar after ultra-low temperature freeze-thaw cycle is much greater than that of low temperature freeze-thaw cycle(-20～20 ℃).Among them,when the double-doped fly ash is mixed with 15％and the silica fume is mixed with 10％,the mechanical performance of cement mortar is the best.After 10 super-low temperature freeze-thaw cycle,the flexural strength and compressive strength reach 10.06 MPa and 38.29 MPa respectively.At this time,the loss rate of cement mortar strength is the lowest and the frost resistance is the best;the pore size reaches a minimum of 33.15 nm,and the porosity is also a minimum of 13.58％.
ultra-low temperature freeze-thaw cyclemineral admixturecement mortarloss of strengthfrost resistancepore structure
万方数据
维普
