Comportamiento mecánico del hormigón de recubrimiento frente a los productos de corrosión de las armaduras

Mechanical bahavior of the cover concrete relationed to the formation of reinforcement corrosion products

This experimental work was carried out in order to reach a better understanding on the mechanical processes that lead to the cracking and to the end of the reinforced concrete structures service life, due to the harmful action of expansive corrosion products. In the experimental procedure it was established variations in the concrete internal structure (water/cement ratio = 0.4 and 0.7), in the concrete cover (0.5 and 2.5 cm) and in the chloride amount in concrete (1 % and 4% of CaCl2-base setting and hardening accelerator admixture by cement weight); with the corrosion having been induced by impressed current, kept constant to all the testing situations. The main results of the study have showed that concretes having the smallest cover, the lowest water/cement ratio and/or the lowest amount of chlorides, have presented the lower testing time (up to the cracking) in relation to the others concretes. The experimental work have also showed that strain levels needed to produce cracking in concrete were sig-nificantly higher to concretes with 1% of admixture incorpo-rated as weil as to those of 0.7 water/cement ratio.