The effect of particulate reinforcement on strength and deformation characteristics of fine-grained concrete
One of the options to improve the reliability and increase the service life of concrete structures can be a reinforcement of the total volume of fine-grained concrete with different fiber types. The article presents the results of complex researches on studying of influence of parameters of the dispersed reinforcement (fiber, length and type of fiber, dosage by volume) and the material of the fibers of strength of disperse-reinforced fine-grained concrete on a stretching at a bend, the estimation of efficiency and accountability in the calculation of building structures. The article considers the possibility of using industrial materials. It is proven that rougher texture leads to a larger force of adhesion between the particles of filler and the cement matrix. In addition, the large surface area of angular aggregate facilitates the development of greater traction. The article considers the issues of application of steel fibers to disperse reinforcement of fine-grained concrete. As a binder we used fine ground cement and the binder with low water demand. Their physic-mechanical characteristics of binders were studied. From the results of experiments it was found that grinding cement with plasticizing additive "Polyplast SP-1" in the amount of 0.6 % by weight of cement is more intense. This shows that in addition to the plasticizing action, it has an intensifying effect at grinding; this is due to the wedging action of most additives. It is also seen that the kinetics of grinding TMC and VNV on attrition crushing granite similar and previously studied industrial raw materials. As reinforcing material steel wave fiber were used. For increasing the strength and deformation characteristics were developed by the compositions of fine-grained fiber-reinforced concrete on technogenic raw materials (screening instruments) and composite binders with the use of nanodispersed powders (NDP). The use of composite binder and high-density packing of grains of filler significantly increases the strength characteristics. Optimal selection of filler allowed to receive on technogenic Sands of Kursk magnetic anomaly of the fiber-reinforced concrete with strength limit under compression – 160.2 MPa, at a bend of 31.2 MPa.