Research on hydration heat temperature field in mass concrete side wall of large water pump station

Author(s):  
Shen Pangyong ◽  
Hu Xiangdong ◽  
Zhou Bin ◽  
Li Fuqing ◽  
Wang Zhenhua
2014 ◽  
Vol 8 (1) ◽  
pp. 482-487 ◽  
Author(s):  
Jun Peng ◽  
Chunping Tang ◽  
Liangliang Zhang ◽  
Ayad Thabit Saeed

Measuring points were observed continuously to reveal the hydration heat temperature distribution of hollow concrete bridge pier. The results showed that as the thickness of the pier increased, the central temperature of the pier increased significantly due to hydration and the heat was difficult to be dissipated. The hydration temperature accounted for up to 70% of the maximum temperature rise during 20 h and reached the maximum temperature at 24 h after pouring the concrete. There was a jump value between the central temperature and surface temperature in a short period after removing the framework. The jumping was the most dangerous moment for the cracking of pier surfaces. Therefore, the formwork removal time has to be determined prudently and corresponding measures have to be conducted to reduce the possibility of pier surface cracking.


2021 ◽  
Vol 283 ◽  
pp. 01032
Author(s):  
XiZhi Wang ◽  
MinSheng Shi ◽  
XinGang Wang

The structural deformation caused by temperature change is the main reason for cracking of mass concrete. In order to avoid or reduce the crack of the side wall of cast-in-place mass concrete in tunnel, the effects of different dosage of hydration heat inhibitor on the internal temperature rise curve of concrete, strength and the properties of the mixture are analyzed through experimental research, and the optimal dosage of 1% of cementing material is finally determined. The engineering application results show that after adding hydration heat inhibitor to the tunnel side wall concrete, the maximum temperature rise in the tunnel side wall is obviously reduced, and the arrival time of the temperature peak is delayed. No cracks appear in the tunnel side wall, and the crack control effect is good.


2013 ◽  
Vol 353-356 ◽  
pp. 3649-3653
Author(s):  
Liang Zhao ◽  
Liang Liang Zhang ◽  
Zhi Yong Yang

Hydration heat, one of the most severe factors, makes great effects on the mass concrete construction, especially on bridge structures and dam structures. Based on the experiment, this paper adopted large-scale finite element method with ANSYS software to analyze the transient temperature field during concrete placement. The atmosphere temperature, construction method, thermodynamics as well as material parameters (cement hydration heat, elastic modulus) were taken into account. The results clarity the distribution characters and process of the hydration heat temperature and stress. Besides, the computational and experimental results were compared. The results indicate that the surface cracks occur due to the large stress which is induced by the extensive internal and external temperature difference. As a result, references are provided to avoid harmful temperature cracks during pier construction period.


2011 ◽  
Vol 243-249 ◽  
pp. 1589-1596
Author(s):  
Xu Hui He ◽  
Hao Cheng ◽  
Hong Xi Qin

The temperature control of mass concrete is regarded to be a universal problem. Because of the heavy load of railway cable-stayed bridges, the pile caps usually have large dimensions, so the thermal stress, which is caused by hydration heat, must be emphasized. In order to study the spatial distribution of temperature in mass concrete and find a functional temperature control measure during construction, the theoretical and FEM analysis of hydration heat-thermal stress field are applied, which can improve structural reliability and provide reference for design and engineering of the similar project. Based on FEM calculation, the theoretical hydration heat temperature field is obtained. In the same time, the temperature sensors as well as strain sensors are arranged in the key position of pile cap. Then the variation of hydration temperature in concrete would be measured and recorded since the concrete is pouring. According to the theoretical simulation and the monitoring results, the time-history curve of hydration heat is obtained, and the variation of inner temperature gradient along the height direction as well as the longitudinal direction with the concrete age are studied, and the feasibility of temperature control measures is also verified.


2017 ◽  
Author(s):  
Keshi You ◽  
Feng Wang ◽  
Liujiang Wang ◽  
Zhongwei Zhao ◽  
Yun Liu

2021 ◽  
Vol 13 (5) ◽  
pp. 771-780
Author(s):  
Shou-Kai Chen ◽  
Bo-Wen Xu

The adiabatic temperature rise model of mass concrete is very important for temperature field simulation, same to crack resistance capacity and temperature control of concrete structures. In this research, a thermal kinetics analysis was performed to study the exothermic hydration reaction process of concrete, and an adiabatic temperature rise model was proposed. The proposed model considers influencing factors, including initial temperature, temperature history, activation energy, and the completion degree of adiabatic temperature rise and is theoretically mature and definitive in physical meaning. It was performed on different initial temperatures for adiabatic temperature rise test; the data were employed in a regression analysis of the model parameters and initial conditions. The same function was applied to describe the dynamic change of the adiabatic temperature rise rates for different initial temperatures and different temperature changing processes and subsequently employed in a finite element analysis of the concrete temperature field. The test results indicated that the proposed model adequately fits the data of the adiabatic temperature rise test, which included different initial temperatures, and accurately predicts the changing pattern of adiabatic temperature rise of concrete at different initial temperatures. Compared with the results using the traditional age-based adiabatic temperature rise model, the results of a calculation example revealed that the simulated calculation results using the proposed model can accurately reflect the temperature change pattern of concrete in heat dissipation conditions.


2018 ◽  
Vol 38 ◽  
pp. 03020 ◽  
Author(s):  
Zheng Si ◽  
Qian Zhang ◽  
Ling Zhi Huang ◽  
Dan Yang

Most existing temperature field calculation programs have relative defects. In the present paper, based on merits of ANSYS platform, a temperature field calculation program of mass concrete structure is developed and demonstrated. According to actual pouring progress and thermodynamic parameters, a roller-compacted concrete dam is simulated. The difference of maximum temperature between calculated and measured values of measuring points is less than 1.8°C. Furthermore, the relative difference is -5%–5%. This result shows that the calculation program developed based on ANSYS platform can simulate and calculate the temperature field of mass concrete structure.


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