Original scientific paper

https://doi.org/10.17559/TV-20230426000576

Effect of Different Water-Binder Ratios and Fiber Contents on the Fluidity and Mechanical Properties of PVA-ECC Materials

Qin Xin ; (1) College of Civil Engineering and Architecture, Hebei University, No. 180, Wusi East Road, 071002 Baoding, Hebei Province, China (2) Technology Innovation Center for Testing and Evaluation in Civil Engineering of Hebei Province, China (3) Hebei University of Technology Civil Engineering Postdoctoral Mobile Station, China
Ruyu Gao ; College of Civil Engineering and Architecture, Hebei University, China No. 2666 QiYi Road, Baoding County, Hebei Province, China
Pengtao Shao ; College of Civil Engineering and Architecture, Hebei University, China No. 2666 QiYi Road, Baoding County, Hebei Province, China
Wenbo Lv ; College of Civil Engineering and Architecture, Hebei University, China No. 2666 QiYi Road, Baoding County, Hebei Province, China
Hao Wei ; College of Civil Engineering and Architecture, Hebei University, China No. 2666 QiYi Road, Baoding County, Hebei Province, China

Abstract

With the development of fiber-reinforced cement composites, the diversity and complexity of application scenarios require enhanced strength and ductility and tough materials in practical engineering. To explore the effects of different water-binder ratios and fiber contents on the fluidity, bending resistance, tensile properties, fracture toughness, and fracture behavior of polyvinyl alcohol (PVA) fiber cement composites, several groups of high ductility test blocks (PVA-engineering cementitious composites (ECC)) with different mixing ratios were designed in this study. Based on the expansion degree, the mechanical experimental data, and the electron microscopy scanning image results, K-value analysis was performed on the strain hardening strength criterion. The effect of the water–binder ratio and the fiber dosing on the PVA-ECC material was determined. Results show that the greater the water-binder ratio is, the better the fluidity of the ECC matrix is. In the same cement system and at the same water-binder ratio, the fluidity of the ECC paste gradually deteriorates with the increase of the fiber content. The water-binder ratio significantly affects the flexural tensile strength of the composite. The flexural and tensile strengths of the PVA-ECC gradually increase as the water-binder ratio decreases, but the ductility gradually decreases. The water-binder ratio of the substrate directly influences the damage behavior of the fibers within the substrate. With the gradual increase of the water-binder ratio, the fiber at the crack interface gradually changes from pull-out morphology to fracture morphology. The strain capacity and the multi-crack cracking performance decrease. To achieve improved working performance in the actual project, the matrix water-binder ratio should be controlled at approximately 0.45, and the PVA fiber dose of 1.7% is optimal. This study can provide a good reference for the optimization of practical engineering components.

Keywords

fiber reinforced cement-based composites; fluidity; mechanical properties; PVA-ECC

Hrčak ID:

307698

URI

https://hrcak.srce.hr/307698

Publication date:

31.8.2023.

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