Zhang Peng, Yang Yonghui, Wang Juan, Jiao Meiju, Ling Yifeng
School of Water Conservancy Engineering, Zhengzhou University, Zhengzhou 450001, China.
Department of Civil, Construction and Environmental Engineering, Iowa State University, Ames, IA 50011, USA.
Materials (Basel). 2020 Dec 2;13(23):5495. doi: 10.3390/ma13235495.
Cementitious composites have good ductility and pseudo-crack control. However, in practical applications of these composites, the external load and environmental erosion eventually form a large crack in the matrix, resulting in matrix fracture. The fracture of cementitious composite materials causes not only structural insufficiency, but also economic losses associated with the maintenance and reinforcement of cementitious composite components. Therefore, it is necessary to study the fracture properties of cementitious composites for preventing the fracture of the matrix. In this paper, a multi-crack cracking model, fictitious crack model, crack band model, pseudo-strain hardening model, and double-K fracture model for cementitious composites are presented, and their advantages and disadvantages are analyzed. The multi-crack cracking model can determine the optimal mixing amount of fibers in the matrix. The fictitious crack model and crack band model are stress softening models describing the cohesion in the fracture process area. The pseudo-strain hardening model is mainly applied to ductile materials. The double-K fracture model mainly describes the fracture process of concrete. Additionally, the effects of polyvinyl alcohol (PVA) fibers and steel fibers (SFs) on the fracture properties of the matrix are analyzed. The fracture properties of cementitious composite can be greatly improved by adding 1.5-2% PVA fiber or 4% steel fiber (SF). The fracture property of cementitious composite can also be improved by adding 1.5% steel fiber and 1% PVA fiber. However, there are many problems to be solved for the application of cementitious composites in actual engineering. Therefore, further research is needed to solve the fracture problems frequently encountered in engineering.
水泥基复合材料具有良好的延展性和伪裂缝控制能力。然而，在这些复合材料的实际应用中，外部荷载和环境侵蚀最终会在基体中形成大裂缝，导致基体断裂。水泥基复合材料的断裂不仅会导致结构失效，还会带来与水泥基复合材料构件维护和加固相关的经济损失。因此，研究水泥基复合材料的断裂性能以防止基体断裂是很有必要的。本文介绍了水泥基复合材料的多裂缝开裂模型、虚拟裂缝模型、裂缝带模型、伪应变硬化模型和双K断裂模型，并分析了它们的优缺点。多裂缝开裂模型可以确定基体中纤维的最佳掺量。虚拟裂缝模型和裂缝带模型是描述断裂过程区粘结力的应力软化模型。伪应变硬化模型主要应用于韧性材料。双K断裂模型主要描述混凝土的断裂过程。此外，分析了聚乙烯醇（PVA）纤维和钢纤维（SFs）对基体断裂性能的影响。添加1.5-2%的PVA纤维或4%的钢纤维（SF）可大大改善水泥基复合材料的断裂性能。添加1.5%的钢纤维和1%的PVA纤维也可改善水泥基复合材料的断裂性能。然而，水泥基复合材料在实际工程中的应用仍有许多问题需要解决。因此，需要进一步研究以解决工程中经常遇到的断裂问题。
