Carbonation-induced corrosion minimization in steel reinforced concrete structures

Abstract

The aim of the work was to find out the corrosion condition, cause and remedial solution for reinforced concrete structures located at non coastal regions. Concrete cover thickness ranged from 12cm to 50cm. Rebound hammer strength ranged from (12-28) N/mm2. The pH ranged between 8 and 12 but 85% of pH was below 10. Results show that for corrosion conditions more than 80% quai-situation value lay between (-0.420 and 0.380) VCSE which indicates high probability of corrosion of reinforcement. Real structures surveyed also indicated that they were devoid of maintenance schedules. Irrespective of structural member, survey data on analysis indicate an average carbonation coefficient (K) of 3.83mm/year(0.5) in concrete structure exposed to Bangalore atmosphere. Hence, the study indicates that regular maintenance schedules for reinforced concrete structures are essential with preventive approach. Carbonation induced corrosion was accelerated by 490ppm concentration of Carbon dioxide in the surrounding environment of the surveyed structures. It was facilitated by the deficiency in construction practices like inadequate concrete cover, high w/c ratio hence poor quality of concrete in general. (C) 2017 The Authors. Published by IASE.