The research paper discusses the tests conducted on single- and double-span concrete slabs longitudinally reinforced with BFRP rebar.
It was found that load bearing capacity of these members is mainly determined by concrete strength properties because BFRP rebar has higher tensile strength and yield strain so it is not easy to break.
Fracture behaviour of concrete slabs in two experiments corresponds to concrete brittle failure in the compression zone. The deflection values are very high.
Therefore, load-bearing capacity of BFRP members in concrete slabs is expected to be mainly determined by the quality of concrete and the method of rebar fixture.
So, for the practical use, it would be advisable to adopt an additional partial coefficient for concrete, taking into account this fact.
The extremely high deflection values caused by relatively low modulus of elasticity of BFRP rebar (twice as low as steel rods at least) preclude using BFRP rebar as a simple alternative to steel rebar in reinforced concrete structures.
Deflection can be reduced by replacement of flexural steel-reinforced concrete members with BFRP rebar, but in this case the economic value of composite BFRP rebar will be lower.
Deflection of the tested members was high but elastic.
BFRP rebar seems to be more effective when used in structures subjected to shock loads: protective elements of road guard railings or facade panels subjected to shock loads.
Marcin Abramski, Piotr Korzeniowski, Marek Wesolowski
Gdansk Polytechnic University