Complex additives for concretes on the base of caprolactam

Abstract

In the modern construction operations, complex multifunctional additives are the most in demand. Application and development of chemical additives enable to consider the modern concrete as a complex composite material, with the properties surpassed the combinations of the properties of its components. In the paper, the action mechanisms of various types of plasticizers and superplasticizers are studied as well as their impact on the properties of concrete mixture and concrete. The most popular plasticizers of concrete mixtures are superplasticizer C-3, alkaline waste of caprolactam process, and technical lignosulphonates. The products of oligomerization of ɛ-caprolactam in the organic substance medium or its interaction with various sustances of synthetic or natural origin are considered perspective multifunctional additives of building mixes. In the paper, the properties of additives obtained by the method of mechanochemical activation of the mixture containing oligomers of ɛ-caprolactam, superplasticizer C-3, technical lignosulphonate, and inorganic salts are researched. The carried out investigation has demonstrated improved plasticizing and water retention properties of the additives as well as acceleration of concrete stress generation at the early strength stage. Based on the research findings for the obtained complex additives for the concrete B40, it was stated that the additives obtained by mechanochemical activation of the initial mixture perform as effective plasticizers and concrete hardeners.