Durability indices for concretes with different dosages of mineral admixtures

摘要

This paper is an attempt to develop a database for durability indices for low to medium strength concretes, using the common binders in Indian conditions. The experimental investigations are limited to mixes with water-binder ratio 0.50, having a binder content of 310 kg/m~3. The durability tests include rapid chloride permeability test, chloride conductivity, oxygen permeability and water sorptivity, conducted at 28th and 90th day. This database acts as a guideline for choosing most economical and durable mixes for a particular strength grade, with optimum mineral admixture dosages and combinations. It has been observed that mixes using combinations of different mineral admixtures perform better than those with single mineral admixture. The paper concludes with a discussion of the synergies between the additives, and also presents a way forward for durability based specifications.