Experimental study on the mechanical behaviour of short chopped basalt fibre reinforced concrete beams

Abstract

The use of short chopped basalt fibres (CBFs) in concrete structures, as a promising alternative to conventional fibres, is of great importance to the sustainable development and plays a well-balanced role between strength improvement and workability in construction. Hence, this paper successively presents two series of test programs. Series Ⅰ as the preliminary material tests is conducted to understand the effects of short CBFs on concrete matrix, while Series Ⅱ as the beam tests is primarily to explore the flexural performance of concrete beams mixed with CBFs based on various three kinds of parameters. The results showed that in Series Ⅰ, the inclusion of CBFs can relieve the crack patterns from a sudden failure to a more ductile behaviour, and effectively upgrade the flexural strength of concrete. While in Series Ⅱ, concrete beams mixed with CBFs can help enhance the crack-resistance ability and greatly improve the flexural behaviour during the working stage. In addition, the improvement effects were enlarged with increasing fibre length, and that were reduced as the tensile reinforcement ratio increases. An FRL height ratio of 0.35 was suggested to ensure that the composite beams worked well and to avoid potential interface issues. Finally, the calculated methods of cracking moment and section stiffness during the service life, were proposed and verified by collecting other test data.