Short-term and Long-Term Deformations of the Lightweight Concrete

Abstract

Abstract The article is devoted to the study of the short-term and long-term deformations of the lightweight concrete which has found ever-growing use in various fields of construction. The main direction of the lightweight concrete usage is its application in the load-bearing and enclosing structures of buildings and structures. The lightweight concrete has fundamental differences from heavy weight concrete and this is primarily due to the special characteristics of the porous aggregates in their composition. Concretes with such aggregates as expanded clay, expanded perlite and agloportite with strength from 10 to 60 mPas, whose deformative properties are represented by the stress – strain diagram in fig.1, have been investigated in this work. The dependence of the diagrams completeness on the type of aggregate at various concrete strength indexes is given in Table 1. The ascending branches of the diagram for the whole range of the strength has ended when a deformation has reached 2,2·103. The concrete stress corresponding to the limiting compressive strain of all types of concrete has been 85% of the maximum value. All the diagrams intersect at one point, the descending branches diverge at a stress level of 0.75 and the deformations have been 2,9…3,7·103. The data obtained as a result of the investigation can be used to calculate the normal sections of bending and eccentrically compressed elements with allowance made to the properties of the lightweight concrete that significantly expand its promising applicable scope in areas with complex geological conditions and in seismic areas.