再生骨料混凝土的制备及抗压强度的试验研究

Study on the preparation and compressive strength of recycled aggregate concrete

制备了不同替代率(水∶水泥∶砂∶石=0.5∶1∶1.19∶2.21)的再生骨料混凝土并进行单轴压缩试验。分别研究再生骨料替代率(0%、25%、50%、75%和100%)、粉煤灰替代率(0%、15%、30%和45%)及纳米SiO 2添加率(0%、1%、2%和3%)对其抗压强度的影响。试验结果发现:混凝土抗压强度随再生骨料替代率增加而增加。单掺粉煤灰和单掺纳米SiO 2时,抗压强度均呈为先降低后增加再降低规律。粉煤灰最佳替代率30%,纳米SiO 2最佳添加率2%。

Recycled aggregate concretes with different mix proportions(water∶cement∶sand∶stone=0.5∶1∶1.19∶2.21)were prepared and tested for their compressive strength.Recycled aggregate replacement rate(0%,25%,50%,75%and 100%),fly ash addition rate(0%,15%,30%and 45%)and nano-silica addition rate(0%,1%,2%and 3%)on its compressive strength was studied.The results show that:The compressive strength of concrete increases as the replacement rate of recycled aggregate increases.After fly ash and nano-silica were added separately,the compressive strengths both decreased first,then increased and then decreased.The optimal replacement rate of fly ash is 30%,and the optimal addition rate of nano-silica is 2%.