Critical Amount of Corrosion for Crack Initiation Along Reinforcements

Abstract

The critical amount of corrosion for initiating cracking along reinforcements was studied by wet and dry exposure tests and by RBSM analysis. The experiments showed that the critical amount of corrosion was in the range of 10 to 100 mg/cm 2 and was influenced by water-binder ratio of concrete, cover thickness and bar diameter. The results of the RBSM analysis showed similar tendencies with the experimental ones, when tension softening of concrete and crack development were taken into account. A modifying coefficient, however, was necessary for the critical values obtained by the two methods to coincide. Based on the results, some equations to express the critical amount of corrosion were proposed, taking water-binder ratio, cover thickness and bar diameter into account.