Effect of Thermal Parameters on Hydration Heat Temperature and Thermal Stress of Mass Concrete

Yuqin Zhao,Wentai Pang,Yongtao Wang,Caixia Fan,Gaosheng Li,Yanhu Mu

doi:10.1155/2021/5541181

Abstract

To explore the influence of concrete thermal parameters on the hydration heat temperature and thermal stress of mass concrete, four feature positions of a dam foundation were chosen to analyze the changing process of temperature and stress by varying the thermal parameters, including the thermal conductivity, specific heat, surface heat diffusion coefficient, temperature rise coefficient, solar absorption coefficient, and thermal expansion coefficient. Some conclusions were obtained as follows. Increasing the thermal conductivity and reducing the specific heat and temperature rise coefficient of concrete can effectively reduce the maximum temperature of the central concrete structure. Increasing the solar absorption coefficient, specific heat, and thermal expansion coefficient and reducing the thermal conductivity, surface heat diffusion coefficient, and temperature rise coefficient of concrete can reduce the maximum principal tensile stress in the structure to a certain extent. The maximum principal tensile stress at different positions of the structure has a linear functional relationship with the thermal conductivity, specific heat, and thermal expansion coefficient and has a quadratic function relationship with the surface heat diffusion coefficient, temperature rise coefficient, and solar absorption coefficient. Besides, this study also proposed a series of related anticracking measures. This study was expected to provide a theoretical reference for the design, construction, and cracking disease prevention of mass concrete structures.

Highlights

To explore the influence of concrete thermal parameters on the hydration heat temperature and thermal stress of mass concrete, four feature positions of a dam foundation were chosen to analyze the changing process of temperature and stress by varying the thermal parameters, including the thermal conductivity, specific heat, surface heat diffusion coefficient, temperature rise coefficient, solar absorption coefficient, and thermal expansion coefficient
A threedimensional finite element model considering hydration heat release, thermal parameters changing, and actual temperature boundary was built to analyze the maximum temperature, the temperature difference between the core and surface, and maximum principal tensile stress of the mass concrete aiming to study the influence of different values of thermal conductivity, specific heat, surface heat diffusion coefficient, temperature rise coefficient, solar absorption coefficient, and thermal expansion coefficient on the distribution of temperature and thermal stress at the core, surface, 50 mm from the surface, and foot of the concrete foundation
Based on the concrete foundation model, the influence of each thermal parameter on the maximum temperature, the temperature difference between the core and surface, and maximum principal tensile stress of mass concrete are analyzed by using the control variate method

Summary

Introduction

To explore the influence of concrete thermal parameters on the hydration heat temperature and thermal stress of mass concrete, four feature positions of a dam foundation were chosen to analyze the changing process of temperature and stress by varying the thermal parameters, including the thermal conductivity, specific heat, surface heat diffusion coefficient, temperature rise coefficient, solar absorption coefficient, and thermal expansion coefficient. Si et al [38] put forward a new idea that the small temperature difference cooling can effectively reduce the temperature gradient and thermal stress These findings mainly focused on revealing the influence of construction design, amount and type of concrete raw materials, pipe cooling parameters on the hydration temperature, and thermal stress distribution of mass concrete. A threedimensional finite element model considering hydration heat release, thermal parameters changing, and actual temperature boundary was built to analyze the maximum temperature, the temperature difference between the core and surface, and maximum principal tensile stress of the mass concrete aiming to study the influence of different values of thermal conductivity, specific heat, surface heat diffusion coefficient, temperature rise coefficient, solar absorption coefficient, and thermal expansion coefficient on the distribution of temperature and thermal stress at the core, surface, 50 mm from the surface, and foot of the concrete foundation. The study puts forward a series of relevant crack prevention measures. e results will provide a theoretical basis for temperature control and crack prevention of mass concrete structures from the perspective of controlling the thermal properties of concrete materials

Methods

Results

Conclusion