摘要
To obtain the design parameters of the structure made by ecological high ductility cementitious composites(Eco-HDCC),the effects of curing age on the compressive and tensile stress-strain relationships were studied.The reaction degree of fly ash,non-evaporable water content and the pH value in pore solution were calculated to reveal the mechanical property.The results indicate that as the curing age increases,the peak compressive strength,peak compressive strain and ultimate tensile strength of Eco-HDCC increase.However,the ultimate compressive strain and ultimate tensile strain of Eco-HDCC decrease with the increase in curing age.Besides,as the curing age increases,the reaction degree of fly ash and non-evaporable water content in Eco-HDCC increase,while the pH value in the pore solution of Eco-HDCC decreases.Finally,the simplified compressive and tensile stress-strain constitutive relationship models of Eco-HDCC with a curing age of 28 d were suggested for the structure design safety.
为了获得生态高延性水泥基复合材料(Eco-HDCC)在结构设计中所需要的参数,研究了养护龄期对Eco-HDCC抗压和抗拉应力-应变关系的影响,并计算粉煤灰反应程度、非蒸发水含量和孔溶液pH值以揭示力学性能.结果表明:随着养护龄期的增加,Eco-HDCC的抗压强度、峰值压应变和极限抗拉强度均呈增加趋势,而龄期对Eco-HDCC极限压应变和极限拉伸应变有负面影响;随着龄期的增加,粉煤灰反应程度和非蒸发水含量逐渐增加,而孔溶液的pH值却呈降低趋势.考虑结构设计的安全性,建议使用养护28 d后Eco-HDCC简化的抗压和抗拉应力-应变关系.
基金
The National Natural Science Foundations of China(No.51778133)
the Transportation Science&Technology Project of Fujian Province(No.2017Y057)
the China Railway Project(No.2017G007-C)
Foundation of the China Scholarship Council(No.201906090163).
