Improvingthe Physical and Mechanical Properties of Highly Mobile Heavy Concrete

The article considers the possibility of increasing the strength of heavy concrete obtained as a result of solidification of a highly mobile mixture by introducing polyoxyethylene derivatives of polycarboxylic acids and polyethylene glycol. The introduction of 0.7% plasticizer “relamix pk” makes it possible to obtain heavy concrete with compressive strength at the age of 3 days of hardening under normal conditions of 48.1 mpa, at the standard age of 72.2 mpa. At the same time, the concrete mixture has a water-cement ratio equal to 0.36; the mobility, measured by the spreading of a normal cone, immediately after the preparation of the concrete mixture is 68 cm, after 60 minutes of mixing preparation — 39 cm. The method of multifactorial planning of the experiment was used to select the composition of the concrete mixture and technological parameters. The following indicators were taken as the process responses: compressive strength at the age of 1.3 and 28 days; cone spreading after 0.30 and 60 minutes after the preparation of the batch. As a result of mathematical processing of the experiment, regression equations for the studied characteristics were obtained. The authors revealed that cement consumption has the greatest effect on concrete hardening; plasticizer consumption has the greatest effect on the preservation of the mobility of the concrete mixture.