粉煤灰改性透水再生混凝土力学性能试验研究

通过改变粉煤灰取代率及超掺系数,研究了粉煤灰对不同水灰比及再生混凝土粗骨料取代率透水再生混凝土力学性能的影响。结果表明,粉煤灰等量取代水泥的透水再生混凝土立方体抗压强度、抗折强度及折压比均低于基准透水再生混凝土;当粉煤灰超量取代水泥时,粉煤灰取代率低于20%时的立方体抗压强度、抗折强度及折压比均随超量系数增加而增大,但超量系数超过1.4后效果不明显;粉煤灰取代率为30%时,不同粉煤灰超量系数下力学性能均低于基准试验值;随着再生混凝土粗骨料取代率或水灰比的增大,立方体抗压强度、抗折强度及折压比均随之下降,相同水灰比或再生混凝土粗骨料取代率时,立方体抗压强度、抗折强度及折压比均随粉煤灰超量系数增大而增大,但超量系数超过1.4后效果同样不明显。

Experimental Study on Mechanical Properties of Pervious Recycled Concrete Modified by Fly Ash

Through changing the replacement ratio and excessive incorporation coefficient of fly ash, the effect of fly ash on the mechanical properties of the pervious recycled concrete with different W/C and the replacement ratio of recycled aggregate is studied, and the optimal replacement ratio of fly ash and excess incorporation coefficient are determined. The results show that the cubic compressive strength, flexural strength, and the ratio of flexural strength to compressive strength of pervious recycled concrete with equal amounts of fly ash to replace cement are all lower than those of normal pervious recycled concrete; when the fly ash corctent is over and the replacement ratio of fly ash is lower than 20%, the cubic compressive strength, flexural strength and the ratio of flexural strength to compressive strength increase with the increase of the excessive incorporation coefficient, but the effect is not obvious after the excessive incorporation coefficient exceeds 1.4;When the replacement ratio of fly ash is 30%, the mechanical properties of different fly ash exceesive incorporation coefficients are lower than the benchmark value, so it is recommended that the replacement ratio of fly ash should not exceed20%. With the increase of the replacement ratio of recycled concrete aggregates or the W/C, the cubic compressive strength,flexural strength and the ratio of flexural strength to compressive strength all decrease. Under the same W/C or the replacement ratio of recycled concrete aggregates, the cubic compressive strength, flexural strength, and the ratio of flexural strength to compressive strength all increase with the increase of the fly ash excessive incorporation coefficient, but the effect is not also obvious after the excessive incorporation coefficient exceeds 1.4.