Heavy concrete with mineral additive tripoli

Abstract

Abstract The research results of the effect of active mineral additive tripoli of the deposits of Grishina Sloboda of the Bryansk region on the strength of heavy concrete are presented in the article. The chemical composition and structure of the sedimentary rock tripoli are studied. It is found that the tripoli grinding to the specific surface area of 340 m2/kg leads to the production of concrete class B35 with its content of 5% and class B30 with its content of 10%. The extreme dependence of the concrete strength on the tripoli content after 7 and 28 days of hardening is established. It is shown that the diminution in the sand fineness modulus from 2.87 to 1.14 reduces the concrete strength with 5%-tripoli addition from 38.9 MPa to 21.8 MPa, and with its content of 10% from 36.3 MPa to 20.4 MPa. The dependence of heavy concrete strength after 7 and 28 days of hardening on the content of its components was determined by the method of mathematical planning of the experiment, it allows predicting the values of this indicator when varying the composition of the concrete mixture.