DEFORMABILITY OF CONCRETE BASED ON A BINDER WITH CLINKER KILN DUST

Abstract

He article is devoted to the study of the influence of the composition of the binder of low water demand, containing blast-furnace slag and cement kiln dust, as well as technological factors on crack resistance, shrinkage deformation and frost resistance. The analysis of the influence of the structure of cement stone on the elastic properties of concrete was carried out. The main calculation formulas are considered that allow predicting the modulus of elasticity, taking into account the structure of cement stone and concrete. The expediency of using the ratio of compressive and tensile strength as a criterion for the crack resistance of concrete is substantiated. The criterion of crack resistance of concrete based on dust and slag binder has been experimentally determined. The influence of the binder composition, the content of the naphthalene-formaldehyde type superplasticizer and the water-binding ratio on the values ​​of this criterion was studied. The influence of the age of concrete on dust-slag binder on its deformability index is shown.

It is shown that the value of the elasticity modulus of concrete on these binders is closely accelerated with their compressive strength and can be roughly calculated using known basic dependencies. The results of determining the shrinkage deformations of concrete are given and the modulus of crack resistance is calculated, which is the ratio of tensile strength to the magnitude of shrinkage deformations. It is shown that concretes based on dust and slag binder are characterized by increased values ​​of deformability.