机制砂高延性工程水泥基复合材料(ECC)的性能研究

Performance study on high ductility engineered cementitious composites(ECC)with manufactured sand

采用双因素方差分析法,研究了水胶比(0.30、0.35、0.40)和砂胶比(0.35、0.45、0.55)对工程水泥基复合材料(ECC)抗压和抗折强度的影响,优选出了最佳水胶比和砂胶比。在此基础上,研究了PVA纤维体积掺量(1.0%、1.5%、2.0%)和机制砂掺量(0、50%、100%)对ECC弯曲韧性的影响,并采用非线性回归法建立了预测模型。结果表明:ECC的最佳水胶比和砂胶比分别为0.30和0.55;掺入适量机制砂能在一定程度上提高ECC的峰值挠度,改善ECC的弯曲韧性;当PVA纤维体积掺量为2.0%、机制砂掺量为50%时,ECC的各项弯曲韧性指标相对最优;建立的机制砂高延性ECC峰值抗弯强度和峰值挠度预测模型的拟合精度较高,具有一定的适用性。

The influence of water-binder ratio(0.30,0.35,0.40)and sand-binder ratio(0.35,0.45,0.55)on the compressive and flexural strength of engineered cementitious composites(ECC)was studied by using the two factor analysis of variance method,and the optimal water-binder ratio and sand-binder ratio were selected.On this basis,the effects of PVA fiber volume contents(1.0%,1.5%,2.0%)and manufactured sand contents(0,50%,100%)on the bending performance of ECC were studied,and a predictive model was established by using nonlinear regression method.The results show that the optimal water-binder ratio and sand-binder ratio for ECC are 0.30 and 0.55,respectively.Adding an appropriate content of manufactured sand can improve the peak deflection and bending toughness of ECC to a certain extent.When the volume content of PVA fiber is 2.0%and the content of manufactured sand is 50%,the various bending toughness indicators of ECC are relatively optimal.The established prediction models of peak bending strength and peak deflection of manufactured sand high ductility ECC have high fitting accuracy and certain applicability.