Effect of Negative Temperatures on the Strength and Deformability of a Reinforced Concrete Element

Abstract

One of the main components of the economic development of the Russian Federation is the current trend in the development of the territories of the Far North and the Arctic. The need for such development is enshrined at the state level in various programs. Experiments on the study of the effect of negative temperatures on the operation of reinforcing steel show that with decreasing temperature, an increase in strength and modulus of elasticity is observed. At the same time, there are no unified recommendations on the deformation and strength properties of reinforcement for calculating reinforced concrete structures under conditions of low and ultra-low negative temperatures. RF standards do not take into account the influence of climatic (up to -70°C) and technological (up to -196°C) negative temperatures on the deformation and strength characteristics of reinforcing steel.The purpose of this work was to experimentally study the effect of negative temperatures (up to -196°C) on the deformation-strength properties of reinforcement, concrete and reinforced concrete rod elements. Concrete prisms 10x10x40 cm, samples of reinforcement of a periodic profile of class A400 and reinforced concrete prismatic rods with a section size of 12x18 cm and a reinforcement percentage of 1.45% were taken as prototypes. At the same time, the negative temperature of the tests varied. As a result of the studies carried out with centrally stretched reinforced concrete elements, it was found that lowering the temperature to -165°С leads to an in-crease in the cracking force by 162%; strength by 85%. Empirical dependencies are proposed to determine the deformation-strength characteristics of reinforcing steel, depending on the negative temperature.