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.

Temperature Control Measures Optimization of RCC Gravity Dam

2012 ◽  
Vol 226-228 ◽  
pp. 1153-1156 ◽  
Author(s):  
Shu Ping Huang ◽  
Jian Yun Fu ◽  
Yan Cai Li
Keyword(s):  
Temperature Control ◽  
Simulation Analysis ◽  
Control Measure ◽  
Control Measures ◽  
Gravity Dam ◽  
Mass Concrete ◽  
Dam Construction ◽  
Construction Technology ◽  
3D Fem ◽  
Single Temperature

With the continuous development of dam construction technology, the RCC dam becomes one of the most popular types of dam in the world with its unique advantages. Temperature control measures research is one of the key issues of design and construction of mass concrete structures. How to choose the proper temperature control measures to prevent concrete cracks becomes the important problem of dam construction technology. In a RCC gravity dam, the climate environment is so severe that a single temperature control measure can’t meet the requirements of temperature control and crack prevention. In this paper, 3D FEM simulation analysis is used to calculate temperature field and thermal creep stress field during the whole construction process. According to the simulation results, the temperature control measures design of the dam has been comprehensively evaluated and the temperature control measures of this project have been put forward.

scholarly journals Effect of Hydration Heat Inhibitor on Thermal Stress of Hydraulic Structures with Different Thicknesses

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Wenqiang Xu ◽  
Sheng Qiang ◽  
Zhengkai Hu ◽  
Bingyong Ding ◽  
Bingyong Yang
Keyword(s):  
Thermal Stress ◽  
Stress Field ◽  
Tensile Stress ◽  
Temperature Control ◽  
Hydration Heat ◽  
Control Measures ◽  
Hydraulic Structures ◽  
Hydration Reaction ◽  
Early Hydration ◽  
External Temperature

Concrete hydration heat inhibitor can inhibit the early hydration reaction of concrete and reduce the initial heat release of concrete. However, there is no in-depth research on the effect of hydration heat inhibitor on hydraulic structures with different thicknesses and constraints. In this paper, numerical simulation is used to study the change of temperature and stress field after adding hydration heat inhibitor by establishing the finite element models of tunnel lining, sluice, and gravity dam. The results show that the effect of the hydration heat inhibitors on reducing the temperature peak is inversely proportional to the thickness of the structure. A formula is put forward to evaluate their relation in this paper. When the thickness of the structure is about 6 m, there is no peak cutting effect. For the stress field, hydration heat inhibitor can greatly reduce the thermal stress of the thin-walled structure and make the structure meet the temperature control requirements; for the medium wall thickness structure, it can reduce the internal tensile stress about 50% and the surface tensile stress about 20%, and other temperature control measures are still needed to ensure that the surface tensile stress of the structure meets the requirements; for hydraulic structures with large volume and thickness, the application effect of the inhibitor has limitations, which can reduce the internal tensile stress about 30%, but the tensile stress in the surface area will increase about 7% due to the increase of the internal and external temperature difference; therefore, other temperature control measures such as arranging cooling water pipe, strengthening surface insulation, and so on are needed to ensure that temperature cracks do not occur. This paper provides references and suggestions for the research and engineering application of hydration heat inhibitor.

Temperature Control Technique and Analysis of Mass Concrete in the Pile Cap of Main Pier in Yangtze River Bridge

2014 ◽  
Vol 587-589 ◽  
pp. 1407-1411 ◽  
Author(s):  
Jun Su ◽  
Guo Wang Zuo ◽  
Wei Li
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Temperature Control ◽  
Yangtze River ◽  
Cooling Water ◽  
Control Technique ◽  
Mass Concrete ◽  
Element Analysis ◽  
Pile Cap ◽  
Calculation Results

The paper analyzed the temperature control technique measures of mass concrete in the pile cap of main pier in Yangtze River Bridge. Consider the effect of the cooling pipe, ANSYS finite element analytical software was used to calculate the temperature field of the pile cap in the construction, the distribution rules of the temperature field was simulated by finite element analysis. It is shown that the cooling effect of the mass concrete is obvious by using cooling water pipe, the finite element calculation results can be used to lead to the design and construction. It also provides the reference to develop a reasonable temperature control solutions during the construction of the similar mass concrete.

Study of the Volume Deformation and Stress Development of Concrete Influenced by the Different Cooling Rate

2015 ◽  
Vol 744-746 ◽  
pp. 1495-1498
Author(s):  
Yi Fang ◽  
Xue Feng Song ◽  
Long Chen
Keyword(s):  
Thermal Stress ◽  
Cooling Rate ◽  
Temperature Control ◽  
Control Measures ◽  
Stress And Strain ◽  
Stress Tests ◽  
Volume Deformation ◽  
Cooling Rates ◽  
Stress Development ◽  
Concrete Placement

This paper studied the development of stress and strain influences by different cooling rates based on the concrete thermal stress tests. furthermore, discussed the temperature control measures for early concrete placement.

A MIDAS Simulation Analysis of a Pile Cap’s Pipe Cooling Technology

2014 ◽  
Vol 614 ◽  
pp. 124-127
Author(s):  
Meng Kai Lin ◽  
Hai Lian Li
Keyword(s):  
Field Theory ◽  
Finite Element ◽  
Temperature Field ◽  
Temperature Difference ◽  
Simulation Analysis ◽  
Hydration Heat ◽  
Finite Element Software ◽  
Cooling Method ◽  
Pile Cap ◽  
Cooling Technology

Taking the concrete pouring for a passenger station’s pile cap as the research background, the paper establishes a model of pile cap’s hydration heat, by using the finite element software MIDAS. The paper also studies the main parameters and the temperature field theory which affect the hydration heat. It indicates that the pipe cooling method can significantly reduce the temperature difference between the inside and the outside when pouring massive concretes, and it is an effective way to prevent the generation of cracks.

Experimental Study on Temperature Fields of Dumbbell-Shape Section of CFST Arch Rib and its Effects

2010 ◽  
Vol 163-167 ◽  
pp. 2564-2570
Author(s):  
Bin Yang ◽  
Jin Hua Huang ◽  
Chun Jiao Lin ◽  
Xing Kun Wen ◽  
Mao Jun Liu
Keyword(s):  
Temperature Field ◽  
Temperature Effect ◽  
Time History ◽  
Steel Tube ◽  
Hydration Heat ◽  
Temperature Fields ◽  
Molding Process ◽  
Single Wave ◽  
Arch Bridge ◽  
The Impact

Based on the investigation of a constructing dumbbell-shaped concrete-filled steel arch bridge in Nanning, Guangxi, continuous on-site experimental researches on temperature field and its effects were carried out under the influence of hydration heat of concrete in the molding process of concrete-filled dumb-bell steel tubular arch bridge. On the basis of measured data, analysis on time-history law of temperature field and its effect under the impact of hydration heat of concrete of composite structure of concrete-filled steel tubes is made. The results reveal that temperature variation of hydration heat of the concrete within the steel tube is showed as follows: “Temperature up-continuous high temperature-temperature down-balance”. The structural temperature field, generated under the effect of hydration hea in the process of molding arch rib, is nonlinear temperature field. Concrete hydration temperature effect of crown section basically changes with temperature field simultaneously, while the residual strain of arch foot section is relatively large; hydration temperature effect of L/4 Section emerges peak fluctuations in concrete pouring process and finally levels off. Hydration temperature field of concrete has a great effect on crown section, which makes the steel tube continuously withstand the tension and compression alternatively, while the influence on the arch foot steel tube is not obvious. Surface strains of L/8, L/4, 3L/8 sections of steel tube transit from single-wave peak to dual-wave peak and finally turn into a single wave peak.

Dynamic Simulation Analysis of Temperature Field and Thermal Stress of Concrete Gravity Dam during Construction Period

2011 ◽  
Vol 90-93 ◽  
pp. 2677-2681 ◽  
Author(s):  
Hai Bo Wang ◽  
Sheng Qiang ◽  
Xiao Sun ◽  
Rui Zheng
Keyword(s):  
Temperature Field ◽  
Thermal Stress ◽  
Stress Field ◽  
Dynamic Simulation ◽  
Temperature Control ◽  
Simulation Analysis ◽  
Water Diversion ◽  
Gravity Dam ◽  
Good Effect ◽  
Concrete Gravity Dam

The basic theory of temperature field and stress field of concrete and 3D FEM combining with cooling pipe discrete model and iteration method are used to carry out the dynamic simulation analysis of the temperature filed and stress field of a concrete gravity dam of South-to-North Water Diversion Project. The impacts on cracking mechanism of the surface insulation, internal cooling and environmental climate are considered in calculation. The change laws of temperature field and thermal stress with time and their distributions are analyzed, reasonable temperature control measures are put forward for reference. The results show that good effect of temperature control and cracking prevention is achieved, the proposed measures should have great reference significance to the similar concrete dam in future.

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