Compatibility issues of cement with water reducing admixture in concrete

Abstract

Multiple brand of cement and water reducing admixtures are available in the market, even though these cements and admixture comply with the respective codal provisions there performance are not same in the concrete for each and every brand of cement and water reducing admixture, even if quality and source of other ingredients of concrete is kept same. This has created a lot of confusion among the user about what type/brand of admixture is used with what type/brand of cement and what should be optimum dose of admixture. Common problem associated with incompatibility issue is flash setting, delayed setting, rapid slump loss, improper strength gain and cracking, these not only effect the strength of the concrete but also the durability of the structure. Hence, in the present study different brand/type of cement and water reducing admixture available in the market is used to find study the compatibility issue and optimum dose of admixture. To achieve this marsh cone test has been performed. Test results indicate that the optimum dose of admixture vary from 0.9 to 1.1% of the weight of cement with different type/brand of cement and type/brand of admixture.