Afroughsabet Vahid, Biolzi Luigi, Cattaneo Sara
Department of Architecture, Built Environment and Construction Engineering, Politecnico di Milano, 20133 Milan, Italy.
Department of Civil and Mineral Engineering, University of Toronto, Toronto, ON M5S 1A4, Canada.
Materials (Basel). 2019 Jul 4;12(13):2151. doi: 10.3390/ma12132151.
Calcium sulfoaluminate (CSA) cement has recently gained increased attention due to its lower amount of CO emissions, as compared to that of the ordinary Portland cement (OPC). This paper evaluates the impact of different types of fibers on the engineering features of CSA-based concretes at different water-cement ratios of 0.35 and 0.28. In this study, metallic fibers including double hooked-end steel fibers and hooked-end steel fibers, and non-metallic fibers (i.e., polyvinyl alcohol (PVA) fibers) were utilized at fiber content of 1%. The mechanical properties of concretes were assessed at different curing ages. Dimensional stability of the concrete mixes was also examined. The morphology of the fractured specimens was studied by using the SEM method. The results indicate that the engineering properties of concrete were improved by introducing fibers to the concrete, irrespective of fiber type. The results show that DHE steel fiber has an important effect on the flexural performance of CSA cement-based concretes and results in deflection-hardening behavior. It was observed that fibers and particularly PVA fibers cause a decrease in shrinkage deformation. Microstructure tests demonstrate that prismatic ettringite is the main hydration product of CSA cement-based concrete. The SEM observation also confirms that the inclusion of CSA cement in concrete improves the cohesiveness between the fibers and cement matrix.
与普通硅酸盐水泥（OPC）相比，硫铝酸钙（CSA）水泥由于其较低的二氧化碳排放量，最近受到了越来越多的关注。本文评估了不同类型纤维在水灰比分别为0.35和0.28时对CSA基混凝土工程特性的影响。在本研究中，使用了纤维含量为1%的金属纤维，包括双钩端钢纤维和钩端钢纤维，以及非金属纤维（即聚乙烯醇（PVA）纤维）。在不同养护龄期评估了混凝土的力学性能。还研究了混凝土混合料的尺寸稳定性。通过扫描电子显微镜（SEM）方法研究了断裂试件的形态。结果表明，无论纤维类型如何，向混凝土中引入纤维均可改善混凝土的工程性能。结果表明，双钩端钢纤维对CSA水泥基混凝土的弯曲性能有重要影响，并导致挠曲硬化行为。观察到纤维尤其是PVA纤维会导致收缩变形减小。微观结构测试表明，柱状钙矾石是CSA水泥基混凝土的主要水化产物。SEM观察还证实，混凝土中加入CSA水泥可改善纤维与水泥基体之间的粘结性。
