Durability of alternative binders

The corrosion of rebars due to chloride ingress is a well-recognised problem in structures raised in coastal areas and regions of sub-zero temperature where de-icing salts are used for melting snow. The deterioration of concrete and reinforcement corrosion owing to chloride ingress entails exorbitant cost of repair. Application of ordinary cement as a patch repair in such concrete may not be apt repair solution and may even aggravate the deteriorating condition. Hence, there is need to look for the suitable repair materials for repairing such concretes. Efficacy of various cements to bind chloride chemically or physically should be explored. In addition, repair material must be checked for attributes such as low porosity, permeability and gas permeability to impede further ions diffusion up to the reinforcement level. Potential of various cements with different supplementary cementitious materials to mitigate the ingress of chloride ions and to enhance chloride binding can qualify it as repair materials. Additionally, determination of corrosion rate in rebars surrounded with different repair materials can aid to check whether repair material is helpful in alleviating the propagation of reinforcement corrosion in future. Furthermore, modelling of corrosion rate with application of different cement binder can be beneficial to predict the corrosion condition of reinforcement under chloride ingress and to identify most suitable repair materials.