粉煤灰取代率对再生混凝土断裂性能影响试验研究

为了研究不同粉煤灰取代率对富含砖粒再生混凝土断裂性能的影响,以RC25为基准再生混凝土,并以粉煤灰取代率为0%、10%、20%、30%为变化参数,制作了四组尺寸为100 mm×100 mm×515 mm的富含砖粒再生混凝土三点弯曲梁试件。通过三点弯曲梁的断裂韧度试验,研究了富含砖粒再生混凝土随粉煤灰取代率的变化规律。结果表明:当粉煤灰取代率为10%时,富含砖粒再生混凝土的起裂韧度和失稳韧度提高幅度分别为4.61%和7.44%,当粉煤灰取代率超过10%后,随着粉煤灰取代率的增加,断裂韧度逐渐减小,最大降幅为12.21%。给出了富含砖粒再生混凝土的双K断裂韧度与粉煤灰取代率的关系式。

Experimental study on influence of fly ash on fracture toughness of recycled concrete

In order to study the effect of different fly ash replacement ratio on the fracture performance of brick-rich recycled concrete,four sets of brick-recycled concrete three-point bending beam specimens with dimensions of 100mm×100mm×515mm were produced. Recycled concrete was based on RC25, and the replacement ratio of fly ash was 0%,10%,20% and 30%.. Through the fracture toughness test of three-point bending beam,the variation law of the replacement rate of brick-rich recycled concrete with fly ash was studied. The results show that when the replacement ratio of fly ash is 10%,the increase of cracking toughness and instability toughness of brick-rich recycled concrete is 4.61% and 7.44%, respectively. When the replacement rate of fly ash exceeds 10%, with the increase of the replacement rate of fly ash,the fracture toughness decreases gradually,and the reduction maximum is 12.21%. The relationship between double K fracture toughness and fly ash replacement ratio of brick-rich recycled concrete is given.