Study on flexural behavior of carbon fibers reinforced coral concrete using digital image correlation

In this paper, the flexural behavior, including the flexural damage process, ultimate flexural strength, peak deflection, and flexural toughness, of carbon fibers (CFs) reinforced coral concrete has been investigated by the four-point loading test. The strain fields on the surface of all the specimens were obtained by digital image correlation and used to analyze the flexural damage process. The results show that the flexural damage process can be divided into three phases: Microcrack initiation phase, Macrocrack evolution phase, and Main crack propagation phase. The incorporation of CFs can prolong the deformation process of coral concrete and therefore improve its flexural performance and gradually change its failure mode from brittle to plastic. The optimum dosage of CFs is about 1.5% by weight of the binder, and under the optimum dosage, the ultimate flexural strength, peak deflection, and flexural toughness can be increased by 20.8%similar to 33.3%, 116.2%similar to 142.1%, and 367%similar to 586% for coral concrete with different strength grades, respectively. (C) 2019 Elsevier Ltd. All rights reserved.