Basalt reinforced concrete structures for retrofitting concrete surfaces

Reinforced concrete facades exist since decades exposed to natural weather conditions. Thus nowadays lot of them are damaged by carbonation induced corrosion and therefor require repairing and retrofitting. The aim of this research project is to investigate the possibilities of basalt fibre reinforced concrete as repairing material and also basalt rebars as additional strengthening reinforcement. Investigations with basalt fibre reinforced mortar prisms showed best results in 3 point bending tests, tensile strength and also compressive strength using 0.3 Vol.-% basalt fibres in mixture. The mechanical properties of basalt rebars made of basalt fibre reinforced polymer were tested, showing higher values in tensile strength and Young´s Modulus than comparable steel reinforcement samples. The basalt rebar reinforced concrete samples achieved higher ultimate loads in three-point bending test compared to SRC samples. But after failure in the bonding area no residual load capacity remained. Finally basalt reinforcement bars seems to be well suited for use as retrofitting material for facade elements, but numerous properties have to be examined in further investigations