Study on silica fume improving concrete service life in the freeze-thaw erosion environment of Qinghai
Relying on the alpine high sodium sulfate environment in Qinghai area and the advantages of large stock,high quality and low transportation cost of silica fume,combined with the good mechanical properties of silica fume such as early strength,frost resistance and sodium sulfate resistance.By adding silica fume 0,5％,10％and 15％,in the water-cement ratio of 0.35,sand ratio of 40％,three different sulfate dry-wet erosion and freeze-thaw cycle time ratio of sulfate sodium erosion-freeze-thaw cycle alternating test,and based on the grey system theory,the mechanical properties GM(1,1)prediction model of sulfate sodium erosion-freeze-thaw cycle alternating test is established.The results show that in the sulfate sodium erosion-freeze-thaw cycle alternating environment,the addition of silica fume can reduce the concrete quality,relative dynamic elastic modulus and compressive strength loss rate,and the 10％dosage effect is the best.The compressive strength is first destroyed.It is determined that the freeze-thaw zone environment in Qinghai area is grade D,and the freeze-thaw and dry-wet erosion are 3:1,1∶1 and 1∶3.It is predicted that the life of concrete without silica fume in Qinghai area is 20 years,18.7 years and 13.3 years,and the life of 10％silica fume concrete is 48 years,34.7 years and 18.7 years,respectively.It provides experimental basis and theoretical reference for the use of silica fume concrete in the northwest alpine and sulfate erosion areas and the durability and life prediction of concrete structures under the corresponding environment.
silica fumedry and wetfreeze-thawsulfate erosionGM(1,1)prediction model
万方数据
维普
