Mechanism and strengthening effects of carbon fiber on mechanical properties of cement mortar

Carbon fibers have many advantages, such as low density, low heat transfer and expansion coefficients, high tensile strength, and good chemical stability and thermal conductivity. Aiming to improve the properties, this study investigates the effects of adding different amounts of carbon fiber to cement mortar. First, a fluidity test was performed to determine the effects of different carbon-fiber contents on the fluidity of cement mortar. Thereafter, the effects of the amount of carbon fiber on the flexural and compressive strengths of cement mortar were investigated under consistent fluidity conditions by adding a polycarboxylate superplasticizer. The interfacial transition zone of the carbon-fiber-modified cement mortar and the microstructure and morphology of the hydration products were observed via-scanning electron microscopy. Furthermore, the influence of carbon fibers on the mechanical properties of cement mortar and the associated mechanism were studied.