Time varying temperature effect of hydration heat of massconcrete based on pipe cooling system(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2021年4期
- Page:
- 65-77
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Time varying temperature effect of hydration heat of massconcrete based on pipe cooling system
- Author(s):
- HOU Wei1; 2; SONG Yifan1; 2; MA Chao2
- (1. Key Laboratory of Transport Industry of Bridge Detection Reinforcement Technology, Changan University,Xian 710064, Shaanxi, China; 2. School of Highway, Changan University, Xian 710064, Shaanxi, China)
- Keywords:
- bridge engineering; mass concrete; hydration heat; temperature effect; adiabatic temperature rise; temperature difference between internal and surface
- PACS:
- -
- DOI:
- -
- Abstract:
- In order to study the timevarying temperature effect in the hydration process of mass concrete, Tianninggou Bridge in Loess Area， which is the second highest pier in Asia was taken as the research object, the finite element model of main pier bearing platform was established. The hydration heat and temperature effects of mass concrete bearing platform were analyzed. The accuracy of model was verified by measuring the temperature field on the inner and surface of mass concrete bearing platform with temperature sensors arranged on site. On this basis, the influences of concrete pouring temperature, thermal conductivity coefficient and surface convection coefficient on the internal adiabatic temperature rise, surface temperature rise and temperature difference between the inner and surface of mass concrete bearing platform were analyzed. The results show that the adiabatic temperature rise of mass concrete bearing platform calculated by the finite element method is consistent with the measured results, but its occurrence time is about 60 h later than the measured value. Due to the influence of environmental temperature and thermal insulation measures, the measured temperature on the surface of mass concrete bearing platform fluctuates greatly, and the temperature difference between the inner and surface of mass concrete bearing platform fluctuates. The concrete pouring temperature is linearly correlated with the maximum temperatures of inner and surface of mass concrete bearing platform, and temperature difference between the inner and surface of mass concrete bearing platform. The low concrete pouring temperature can quickly reduce the maximum adiabatic temperature rise in the mass concrete bearing platform. The greater the inner adiabatic temperature rise of concrete is, the greater the influences of concrete pouring temperature on the maximum temperature rises of inner and surface of concrete, and the temperature difference between the inner and surface of concrete. The occurrence time of the maximum adiabatic temperature rise inside the mass concrete bearing platform is related to the logarithm of concrete thermal conductivity coefficient. The larger the thermal conductivity coefficient of concrete is, the greater the maximum adiabatic temperature rise in the mass concrete bearing platform. The concrete surface convection coefficient has little influence on the adiabatic temperature rise of mass concrete bearing platform. However, after the structure enters the cooling stage, the greater the surface convection coefficient is, the faster the internal temperature reduction rate is. The concrete surface convection coefficient has a great influence on the temperature rise of concrete surface. The smaller the concrete surface convection coefficient is, the greater the maximum temperature rise of concrete surface is, and the faster the surface temperature decreases after the structure enters the cooling stage. 6 tabs, 22 figs, 33 refs.
Last Update: 2021-08-12