High-early strength concretes modified with polycarboxylate admixture on different cement types

Abstract

Early and grade strength of modified concrete on different cement types (CEM II/A-S 42,5 and pozzolanic cement CEM IV/A(P) 42,5 R-SR) for concrete pavements repair was explored. Application range of the polycarboxylate modifier was 0.8-1.4% by weight of cement. All concrete compositions had equal workability (slump 5…9 cm). The aim of the investigation was to determine the optimal volume of the polycarboxylate modifier to achieve high strength indicators for repair material at the early and grade age.

High-strength concrete of grades C 50/60 and C 40/50 were obtained, with early strength at the 3 days age above 35 MPa, which allows them to be used as a repair concrete material for rigid road pavements.

X-ray phase analysis confirmed the positive effect of the polycarboxylate admixture in the structure formation of concrete. With an increase in the dosage of the BASF MasterGlenium SKY 608 admixture to 1.2…1.4%, the intensity of the diffractogram lines, which corresponds to the metastable hydration phase in the cement-sand matrix, decreased for concretes on both cement types.