Analysis of temperature control characteristics of electrically conductive roller-compacted concrete during overwintering period

Abstract

The climate of low extreme temperatures and long winter time in alpine regions increases the risk of cracking of concrete dams, and the current thermal insulation measures covered with thermal insulating materials are passive insulation, with cumbersome installation and dismantling procedures. Conductive concrete consists of cementitious materials, conductive materials, etc., both good mechanical properties of concrete materials and unique electro-thermal properties, applied to the overwintering layer of concrete dams and other key parts, both to meet the needs of the dam material performance, but also to maintain the temperature stability of the overwintering layer. Therefore, a finite element model of a typical dam section of a crushed concrete dam in the alpine zone was established, and six overwintering insulation schemes were designed based on the U-ΔT model of the energy supply required for the dam body to resist low temperature, and the temperature control simulation of conventional thermal insulation materials and electrically heated conductive concrete was carried out.The result show that the temperature control of conductive concrete with electric heating can maintain the temperature at the upstream measurement point at 18 ℃, the temperature at the downstream measurement point at 23 ℃, and the temperature at the top measurement point at 30 ℃.[Conclusion]According to the temperature field calculation during the construction period of the crushed concrete dam containing conductive concrete wintering layer, it can be found that the conductive concrete wintering layer electrified in winter has a significant effect on the surface temperature field of the dam, and the temperature difference between the inside and outside of the dam is reduced, which is favorable to the temperature control of the dam, and it can provide new research ideas for solving the temperature control and anti-cracking of the concrete dams in high alpine areas.

Keywords

electrically conductive roller-compacted concrete / U-ΔT model / temperature control / dam temperature field