Concrete beams repaired with geopolymer mortar

ABSTRACT

This work evaluated the effectiveness of a geopolymer mortar as a material for the repair of conventional concrete beams, objectifying to restore the monolithic character and the initial load bearing capacity of the repaired structure. For this, rehabilitated concrete beams with geopolymer mortar and commercial repair mortar were analyzed and compared with reference beams without repair, by means of tests of tensile strength in the flexion and of strengh of flexural shear adhesion. The results show that the greatest deflections occurred for the specimens recovered with geopolymer mortar (when compared to the reference beams of monolithic concrete) without, however, a considerable increase in the rupture load, justified by the low longitudinal modulus of elasticity of the repair material. The beams recovered with geopolymer mortar presented a very similar rupture behavior to the reference beams, that is, they behaved monolithically, unlike those recovered with commercial mortar, which showed substrate/repair interface displacement. The results indicate that the geopolymeric mortar has potential to be used as an alternative material for repairing conventional concrete beams due mainly to the satisfactory adhesion to concrete of the substrate, to the bursting load close to that of the reference monolith beam and to the best quality in relation to commercial mortar.

Keywords
geopolymer mortar; repair; concrete; adhesion