Durability of Concretes Modified with Bioadditives Based on a Microbiological Consortium

Abstract

The article presents data on the assessment of the durability of concretes modified with bioadditives based on a microbiological consortium containing urease bacteria Urobacillus Pasteuri, Sporosarcina pasteurii, Sporosarcina ureae, etc., isolated from the soil. Modified concrete compositions based on Portland cements were developed in accordance with Russian State Standard GOST 31108-2020: Portland cement CEM 0 32.5N, CEM II/A-I 32.5N, CEM II/B-W 32.5N. Modified concrete systems were evaluated by workability, average density, durability and water separation (delamination), and compressive strength after 28 days of hardening. According to the research results, the formulations of the studied formulations were adjusted taking into account the values of the water-cement ratio and the content of dietary supplements at the levels of 0.42-0.45 and 2-3 (%, mass.), respectively. The hardening regime and conditions were studied, as well as the porosity and frost resistance of modified concrete with urease additives were evaluated. The values of the critical stress intensity coefficient during normal separation of modified concrete, as well as the residual durability after concrete operation under conditions of strength and temperature and humidity tests, are calculated. The use of dietary supplements helps to increase the residual durability by more than 10-15% after use under specified conditions.