Influence of recycled coarse aggregates incorporation on the fracture properties of concrete
Influence of recycled coarse aggregates incorporation on the fracture properties of concrete
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DOI：
10.1016/j.conbuildmat.2017.07.183
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发表时间：
2017-11-15
影响因子：
7.4
通讯作者：
Wardeh, George
中科院分区：
文献类型：
--
作者：
Ghorbel, Elhem;Wardeh, George
本文介绍了一种掺粗再生骨料的结构混凝土的力学和断裂性能。根据EN206-1标准设计了四个混合料，达到54稠度级和C35/45级强度。制备了再生砾石体积分数分别为0%、30%、65%和100%的混凝土试件，对10×10×40 cm预缺口试件进行了三点弯曲试验，以确定其抗弯强度和断裂性能，符合Rilem建议。根据实验力-CMOD曲线，利用解析模型和幂函数应变软化关系进行了反分析，得到了本征断裂特性。应变软化规律用幂n和临界裂纹张开位移w(C)两个参数来描述。结果表明，对于再生骨料混凝土，计算的断裂能G(F)与Rilem断裂能G(F)(Rilem)之间的差异更为明显，并研究了幂应变软化规律参数n和w(C)的演化规律。结果表明，功率n取决于抗压强度、骨料尺寸和水胶比。对于同一等级的抗压强度，随着再生骨料含量的增加，抗压强度基本保持不变。对于临界裂纹张开度w(C)，随着取代率的增加而减小。最后建立了断裂性能与抗拉强度之间的关系。(C)2017爱思唯尔有限公司。保留所有权利。
This paper presents the mechanical and fracture properties of a structural concrete incorporating coarse recycled aggregate. Four mixes were designed according to the standard EN 206-1 to achieve 54 consistence class and C35/45 class of strength. Concrete specimens were prepared with different recycled gravel content of 0%, 30%, 65% and 100% by volume of the total coarse gravel.Three points bending tests were performed on 10 x 10 x 40 cm pre-notched samples in order to determine the flexural strength and fracture properties according to the RILEM recommendations. From experimental Force-CMOD curves, the intrinsic fracture properties were obtained by an inverse analysis using an analytical model and a power law strain-softening relationship. The strain-softening law is described by two parameters being respectively the power n and the critical crack opening displacement w(c). It was found that the difference between the calculated fracture energy, G(F), and the RILEM fracture energy, G(F)(RILEM), is more pronounced for recycled aggregate concrete.The evolution of n and w(c), the parameters of the power strain-softening law, was also studied. It appeared that the power, n, depends on the compressive strength, the aggregate size and the water to binder ratio. For the same class of compressive strength, it remains substantially unchanged when the recycled aggregates content increases. For the critical crack opening w(c), it decreases when the substitution ratio increases. Finally, the relationship between fracture properties and the tensile strength has been established. (C) 2017 Elsevier Ltd. All rights reserved.