Constitutive modelling and mechanical properties of cementitious composites incorporating recycled vinyl banner plastics
Constitutive modelling and mechanical properties of cementitious composites incorporating recycled vinyl banner plastics
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DOI：
10.1016/j.conbuildmat.2020.122159
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发表时间：
2021-03
影响因子：
7.4
通讯作者：
D. Bompa;B. Xu;A. Elghazouli
中科院分区：
文献类型：
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作者：
D. Bompa;B. Xu;A. Elghazouli
本文介绍了一个实验研究，这一直缺乏到目前为止，水泥基复合材料的力学性能，包括颗粒和纤维回收增强聚氯乙烯（RPVC）横幅。详细介绍了140多个试验的圆柱体，立方体和棱柱体样品测试在压缩和弯曲，高达20%的矿物骨料取代，给出。根据试验结果，选定的再生材料的单轴性能进行检查结合RPVC颗粒尺寸和几何形状的详细表征。使用数字图像相关技术进行的实验测量能够从压缩应力-应变行为和弯曲应力-裂纹张开曲线以及强度、弹性模量和断裂能等关键力学参数方面详细解释完整的本构响应。结果表明，随着RPVC用量的增加，材料的力学性能呈正比下降。对于矿物骨料的体积替换每增加10%，与常规对应物相比，抗压强度减半，而抗弯强度降低约30%。强度的降低被改善的延展性所抵消，所述改善的延展性由压缩中有利的峰后响应和增强的弯曲软化和开裂后性能表示。较小的颗粒，具有相对较长的针状或三角形的几何形状，表现出更好的行为，因为这些作为纤维与中等和大尺寸的颗粒相比，具有改善的粘结性能。试验结果和观察使一系列表达式的定义，以确定水泥基材料的力学性能，包括RPVC和其他废塑料。然后，这些表达式被用作分析模型的基础，用于评估这种材料的压缩和拉伸应力-应变响应。对本研究中进行的测试，以及从以前的调查进行验证，表明所提出的表达式和开发的本构模型提供可靠的表示实际应用。
This paper describes an experimental study, which has been lacking to date, into the mechanical properties of cementitious composites incorporating granules and fibres from recycled Reinforced PVC (RPVC) banners. A detailed account of over 140 tests on cylindrical, cubic and prismatic samples tested in compression and flexure, with up to 20% replacement of mineral aggregates, is given. Based on the test results, the uniaxial properties of selected recycled materials are examined in conjunction with a detailed characterisation of the RPVC granule size and geometry. Experimental measurements using digital image correlation techniques enable a detailed interpretation of the full constitutive response in terms of compression stress-strain behaviour and flexural stress-crack opening curves, as well as key mechanical parameters such as strength, elastic modulus and fracture energy. It is shown that the mechanical properties decrease proportionally with the amount of RPVC. For each 10% increment of volumetric replacement of mineral aggregates, the compressive strength is halved whilst the flexural strength is reduced by about 30% compared to their conventional counterparts. The reduction in strength is counterbalanced by an improved ductility represented by a favourable post-peak response in compression and an enhanced flexural softening and post-cracking performance. Smaller particles, with a relatively long acicular or triangular geometry, exhibited better behaviour as these acted as fibres with improved bond properties in comparison with intermediate and large size granules. The test results and observations enable the definition of a series of expressions to determine the mechanical properties of cementitious materials incorporating RPVC and other waste plastics. These expressions are then used as a basis for an analytical model for assessing the compressive and tensile stress-strain response of such materials. Validations carried out against the tests undertaken in this study, as well as from previous investigations, indicate that the proposed expressions and the developed constitutive model offer reliable representations for practical application.