Research on hydration heat temperature field in mass concrete baseplate of large water conveyance pump station

2011 ◽  
Author(s):  
Qi Wang ◽  
Zhenhua Wang ◽  
Xiangdong Hu ◽  
Fei Zhao ◽  
Zhongkang Jin ◽  
...  
Keyword(s):  
Temperature Field ◽  
Hydration Heat ◽  
Mass Concrete ◽  
Heat Temperature ◽  
Pump Station ◽  
Water Conveyance ◽  
Large Water

scholarly journals Experimental Research on the Hydration Heat Temperature Field of Hollow Concrete Piers

2014 ◽  
Vol 8 (1) ◽  
pp. 482-487 ◽  
Author(s):  
Jun Peng ◽  
Chunping Tang ◽  
Liangliang Zhang ◽  
Ayad Thabit Saeed
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Hydration Heat ◽  
Maximum Temperature ◽  
Concrete Bridge ◽  
Central Temperature ◽  
Heat Temperature ◽  
Surface Cracking ◽  
Removal Time ◽  
Short Period

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.

Research on Hydration Heat Temperature Stress of the Pier by Finite Element Method

2013 ◽  
Vol 353-356 ◽  
pp. 3649-3653
Author(s):  
Liang Zhao ◽  
Liang Liang Zhang ◽  
Zhi Yong Yang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Large Scale ◽  
Hydration Heat ◽  
Transient Temperature ◽  
Mass Concrete ◽  
External Temperature ◽  
Heat Temperature ◽  
Bridge Structures ◽  
Element Method

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.

Study on Temperature Field and Construction Monitoring of Hydration Heat of Railway Cable-Stayed Bridge Pile Cap

2011 ◽  
Vol 243-249 ◽  
pp. 1589-1596
Author(s):  
Xu Hui He ◽  
Hao Cheng ◽  
Hong Xi Qin
Keyword(s):  
Temperature Field ◽  
Thermal Stress ◽  
Temperature Control ◽  
Structural Reliability ◽  
Control Measure ◽  
Time History ◽  
Hydration Heat ◽  
Control Measures ◽  
Mass Concrete ◽  
Pile Cap

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.

scholarly journals A faster iterative method for solving temperature field of mass concrete with cooling pipes

2017 ◽  
Author(s):  
Keshi You ◽  
Feng Wang ◽  
Liujiang Wang ◽  
Zhongwei Zhao ◽  
Yun Liu
Keyword(s):  
Temperature Field ◽  
Iterative Method ◽  
Mass Concrete ◽  
Cooling Pipes

Kinetic Model of Adiabatic Temperature Rise of Mass Concrete

2021 ◽  
Vol 13 (5) ◽  
pp. 771-780
Author(s):  
Shou-Kai Chen ◽  
Bo-Wen Xu
Keyword(s):  
Temperature Field ◽  
Temperature Rise ◽  
Initial Conditions ◽  
Dynamic Change ◽  
Adiabatic Temperature ◽  
Model Parameters ◽  
Hydration Reaction ◽  
Mass Concrete ◽  
Adiabatic Temperature Rise ◽  
Proposed Model

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.

scholarly journals Development of Simulation Program for Temperature Field of Mass Concrete Structures

2018 ◽  
Vol 38 ◽  
pp. 03020 ◽  
Author(s):  
Zheng Si ◽  
Qian Zhang ◽  
Ling Zhi Huang ◽  
Dan Yang
Keyword(s):  
Temperature Field ◽  
Concrete Structure ◽  
Relative Difference ◽  
Maximum Temperature ◽  
Mass Concrete ◽  
Field Calculation ◽  
Concrete Dam ◽  
Roller Compacted Concrete ◽  
Roller Compacted Concrete Dam ◽  
The Difference

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.

The Arch Support Construction and Hydration Heat Analysis of the First Bridge over Yangtze River in Hejiang

2013 ◽  
Vol 291-294 ◽  
pp. 1122-1127
Author(s):  
Yan Feng Luo ◽  
Da Yan Qin ◽  
Yun Zhang
Keyword(s):  
Yangtze River ◽  
Casting Process ◽  
Hydration Heat ◽  
Maximum Temperature ◽  
Mass Concrete ◽  
Element Analysis ◽  
Early Hydration ◽  
Mix Proportion ◽  
Arch Support ◽  
Heat Preservation

The arch support of the First Bridge over Yangtze River in Hejiang used the stratified and graded casting process in mass concrete pouring process. By means of optimizing the concrete mix proportion design, using high mixing amount of fly ash concrete, reducing heat release rate of concrete early hydration heat, delaying the time of maximum temperature rise, and combining turn-over forms and water storage and other surface heat preservation measures, the temperature difference between inside and outside concrete was reduced and the cracking of mass concrete was avoided. Finite element analysis of hydration heat was done to verify the feasibility of the construction scheme.

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