Compatibility study of water-reducer admixture

Abstract

One of the most important advances in concrete technology has been the development of chemical admixtures. Nowadays, the use of fluidity admixtures has become essential in the production of special concretes, particularly of highperformance concrete, but many incompatibility problems between cement and admixtures have been reported. This study aims to analyze fresh and hard cement properties when water-reducer and high-range water-reducer admixtures and different types of cement are used. Fluidity loss, setting time, and compressive strength were measured. Some incompatibility problems were found. For example, lignosulfonates delayed cement setting time and hardening, as observed by the reduction of compressive strength at day one. However, it was not possible to determine if the performance of those combinations was better or worse, as the different properties that were evaluated did not have consistent behavior. The lignosulfonate-based admixture provided the cheapest mixture as compared to the others.