Modified Concrete Mixes for Monolithic Construction

Abstract

The effect of the multifunctional supplement Linamix PCX and mineral fillers of microsilica and expanded clay dust on the characteristics of concrete mixtures pumped by concrete pumps is investigated. The evaluation of highly mobile and self-compacting concrete mixtures’ properties was carried out according to pumpability criteria that simulate the elastic-viscous structured system flow. The physical and mechanical characteristics of the hardened concrete were determined using standard and generally accepted methods. The ability of the modified concrete to resist tensile stresses was determined by the crack resistance coefficient. The water-reducing efficiency of the superplasticizer was evaluated by the specific consumption of cement per unit of concrete strength. The performed studies have established that the polyfunctional superplasticizer Linamix PCX is an effective modifier of concrete mixtures, rheologically compatible with cements of various material composition. A significant effect of the fine aggregate grain size composition on the properties of highly mobile concrete mixtures and the formation of the hardened concrete structure has been revealed. Evaluation of the modified concretes’ strength characteristics showed that it is rational to use the mixtures with Linamix superplasticizer PCX and microsilica, providing high strength concrete with a minimum specific consumption of cement for concreting massive monolithic structures in order to slow down heat generation during concrete hardening.