MATHEMATICAL MODELING OF THE IMPACT OF RAW MATERIAL COMPOSITION ON COMPRESSIVE STRENGTH OF HIGH PERFORMANCE FINE-GRAINED CONCRETE

Vestnik MGSU 9/2017 Volume 12

Pages 999-1009

Subject of Study: the creation and analysis of mathematical models adequately describing the effect of the input variable factors - the proportions of raw components of the concrete mix - on the compressive strength of high performance fine-grained concrete at the age of 28 days of normal hardening, which are considered as output objective functions. Objectives: to determine the optimum ratios of ingredients of fine-grained concrete mixture, which allow us to achieve the maximum strength of concrete in compression. Materials: for obtaining fine-grained concrete mix, a finely distributed binder was used consisting of Portland cement of the type CEM II 42,5 N produced by the “Hoang Thach” factory, fly ash, rice husk ash (all - Vietnam) with addition of superplasticizer Ace 388 BASF (Germany) and polypropylene fine fibers Mega Mesh (Malaysia). As for the fine filler, quartz sand from the Lo river (Vietnam) was used. Methods: the compressive strength of high performance fine-grained concrete was determined in accordance with the requirements of GOST 10180-2012 “Concretes. Methods of strength determination by control samples”; the initial composition of the concrete mix was calculated using the absolute volume method. Results: the paper presents results of mathematical modeling of the effect of raw materials on the compressive strength of high performance fine-grained concrete at 28 days of normal hardening. First and second order regression equations for the dependence of the compressive strength on the ratio of raw materials x2 () and x3 () and also the image of the surface expression and the contour of the objective function for these regression equations were obtained. Conclusions: The maximum value of compressive strength of high performance fine-grained concrete at 28 days of age, evaluated by using the computer program Maple 13 in the regression equation of the second order, is R = 75.85 MPa at = 0.854 and = 0.324.

DOI: 10.22227/1997-0935.2017.9.999-1009