EXPERIMENTAL INVESTIGATION ON CORROSION OF COTTED REBARS IN REINFORCED CONCRETE

Reinforcement corrosion in concrete is regarded as the predominant factor in the premature degradation of reinforced concrete structures. The failure does not occur due to structural collapse, but also due to loss of serviceability characterized by cracking, spalling, debonding and excessive deflection. The reinforcement corrosion in concrete structures is attributed to combination of factors which includes concrete composition, service environments and loading conditions. It is evident that substantial understanding of corrosion in concrete structures is of foremost importance. Therefore this can only be gained through experiment on concrete structural members under both corrosion process and service loads. For this thesis work, two types of loads are applied 1. 5 % above crack load 2. 5 % below crack load The beams subjected to the above load conditions are allowed for accelerated corrosion process. Monitoring of corrosion of beam specimens is carried out regularly. There are various types of monitoring of corrosion; of which half-cell potential is one effective method. It is based on the electrode potential of steel rebar with reference to a standard electrode undergoing changes depending on a corrosion activity. The parameters like cover thickness, bar diameter and crack width should be taken in to consideration for investigating their effect on reinforcement corrosion. The effect of rice husk ash and silica fume on the reinforcement corrosion is studied