Experimental and Numerical Study of Early-age Cracking of Concrete Slabs Reinforced with Steel and GFRP Bars

Abstract

Problems due to the corrosion of steel reinforcement in concrete structures can be efficiently and economically solved by using fiber-reinforced polymer (FRP) composites. This paper presents the results of experimental tests and numerical simulations of large-scale concrete slab strips symmetrically reinforced with steel and glass fiber-reinforced polymer (GFRP) bars subjected to axial tension. The results showed that due to their lower modulus of elasticity and bond strength, the slabs reinforced with GFRP bars exhibit wider early-age cracks compared to similar slabs reinforced with conventional steel bars. In order to limit the crack width to a certain value, approximately twice the reinforcement ratio of the GFRP bars as in the case of the steel bars is required. This can particularly be a problem for watertight concrete structures of underground facilities and water tanks.