scholarly journals Precise Simulation of Heat-Flow Coupling of Pipe Cooling in Mass Concrete

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5142
Author(s):  
Peng Yu ◽  
Ruiqing Li ◽  
Dapeng Bie ◽  
Xiancai Liu ◽  
Xiaomin Yao ◽  
...  
Keyword(s):  
Heat Flow ◽  
Temperature Gradient ◽  
Temperature Control ◽  
Cooling Water ◽  
Mass Concrete ◽  
Finite Element Software ◽  
Flow Coupling ◽  
Cooling Pipe ◽  
Cooling Effects ◽  
Precise Simulation

For a long time, temperature control and crack prevention of mass concrete is a difficult job in engineering. For temperature control and crack prevention, the most effective and common-used method is to embed cooling pipe in mass concrete. At present, there still exists some challenges in the precise simulation of pipe cooling in mass concrete, which is a complex heat-flow coupling problem. Numerical simulation is faced with the problem of over-simplification and inaccuracy. In this study, precise simulation of heat-flow coupling of pipe cooling in mass concrete is carried out based on finite element software COMSOL Multiphysics 5.4. Simulation results are comprehensively verified with results from theoretical solutions and equivalent algorithms, which prove the correctness and feasibility of precise simulation. Compared with an equivalent algorithm, precise simulation of pipe cooling in mass concrete can characterize the sharp temperature gradient around cooling pipe and the temperature rise of cooling water along pipeline more realistically. In addition, the cooling effects and local temperature gradient under different water flow (0.60 m3/h, 1.20 m3/h, and 1.80 m3/h) and water temperature (5 °C, 10 °C, and 15 °C) are comprehensively studied and related engineering suggestions are given.

scholarly journals Temperature Control Technology for Construction of Jinsha River Bridge

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Hui-Wu Jin ◽  
Guo-An Wang ◽  
Zhan-Ming Chen
Keyword(s):  
Temperature Control ◽  
Temperature Difference ◽  
Cooling Water ◽  
Good Health ◽  
Large Mass ◽  
Maximum Temperature ◽  
Mass Concrete ◽  
Jinsha River ◽  
Mixture Ratio ◽  
Concrete Temperature

The key problem of mass concrete temperature control is to effectively control the maximum temperature inside concrete, the temperature difference between inside and outside concrete, and the temperature difference between surface and environment. The size of the main tower cap of No. 3 Jinsha River Bridge is 37 m × 23.5 m × 5.5 m, and the cubic volume of concrete reaches 4782.3 m3, which is poured in two times. In order to ensure construction quality of mass concrete structure, prevent the large mass concrete temperature stress, through the numerical simulation of the temperature control and optimization scheme, by optimizing the mixture ratio design, reducing the temperature of concrete pouring into the mold, cooling water cycling, insulation keeping in good health and a series of measures to effectively achieve the control goal, and eliminating the temperature cracks. The measured data show that the maximum temperature inside concrete, the temperature difference between inside and outside, and the temperature difference between surface and environment are qualified, but the temperature difference control of cooling water inlet and outlet has hysteresis effect, and the temperature difference between inlet and outlet will be greater than 10°C, which should be noticed.

scholarly journals STUDY ON ARRANGEMENT OF COOLING WATER PIPE TO CONTROL HYDRATION HEAT OF CONCRETE IN BEAM OF CABLE-STAYED BRIDGE

2021 ◽  
Vol 30 (2) ◽  
Author(s):  
Long Liu ◽  
Saisai Yu ◽  
Wentao Xu ◽  
Zhilong Wang
Keyword(s):  
Finite Element ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Hydration Heat ◽  
Inlet Temperature ◽  
Mass Concrete ◽  
Water Pipe ◽  
Finite Element Software ◽  
Joint Section

The box girder joint section of the Yangtze River Highway Bridge is taken as the research background, and the finite element software MIDAS/FEA is used to simulate the hydration heat of concrete to the layout of cooling water pipe in building mass concrete. The finite element calculation results are in well agreement with the measured data. On this basis, the influence of changing the diameter and distance of the cooling water pipe, the inlet temperature and the flow rate on the temperature of hydration heat is studied. The results show diameter of the cooling water pipe and inlet temperature have a significant effect on the temperature of hydration heat. The change of water flow rate has little effect on the temperature of hydration heat. It provides a reference for the layout of the same concrete cooling water pipe arrangement.

A New Method for Improving the Stress Status of the Dam

2013 ◽  
Vol 444-445 ◽  
pp. 849-853
Author(s):  
Jian Hua Cui ◽  
Yong Feng Qi ◽  
Jie Su
Keyword(s):  
Temperature Control ◽  
Cooling Water ◽  
Control Measures ◽  
Sensitivity Analyses ◽  
Mass Concrete ◽  
Water Cooling ◽  
Concrete Gravity Dam ◽  
3D Fem ◽  
Construction Period ◽  
Operation Period

Under the action of annual change and sudden drop of air temperature, thermal induced cracking will occur in concrete dam during the operation period. For exploring the temperature control measures for crack prevention, taking a concrete gravity dam section as the research object, sensitivity analyses to the factors which affecting the water-cooling effect are conducted with 3D FEM, some significant suggestions for the water cooling are presented. The results show that, the stresses of the dam surface will decrease to a certain extent after water cooling in the operation period using the cooling water pipe which embedded during construction period, and the cracking risk of the dam will reduce. The study provides a new train of thought for the temperature control and crack prevention of the mass concrete during the operation period.

Study on the Application of Cooling Pipe in Thin-Walled Concrete Structure

2010 ◽  
Vol 163-167 ◽  
pp. 1107-1110 ◽  
Author(s):  
Zhen Hong Wang ◽  
Guo Xin Zhang ◽  
Yi Liu ◽  
You Zhi Liu
Keyword(s):  
Temperature Control ◽  
Concrete Structure ◽  
Thermal Field ◽  
Early Stage ◽  
Mass Concrete ◽  
Basic Difference ◽  
Cooling Pipe ◽  
Cooling Technology ◽  
Thin Walled ◽  
The Difference

Cracks of concrete structure easily appear in the period of construction and the difference between the inside and outside temperature at early stage and the basic difference of the temperature at later stage are considered as the main factors causing cracks, so the temperature control becomes the key of problem. In view of this problem, this paper puts forward the pipe cooling technology which is usually used in the mass concrete to the thin-walled concrete structure. Under the basic theories of concrete temperature field and numerical algorithm of pipe cooling, the 3-D FEM is adopted to simulate the thermal field of concrete sluice with and without cooling pipe during construction. The results of comparison show that cooling pipe in thin-walled concrete structure can achieve better effect on temperature control, so it should have great reference signification to similar concrete projects in the future.

scholarly journals Temperature-stress coupling mechanism analysis of one-time pouring mass concrete

2019 ◽  
Vol 23 (3 Part A) ◽  
pp. 1615-1621 ◽  
Author(s):  
Ben-Gao Yang ◽  
Peng He ◽  
Gao-You Peng ◽  
Tong Lu
Keyword(s):  
Stress Field ◽  
Temperature Stress ◽  
Temperature Control ◽  
Damage Control ◽  
Control Measures ◽  
Effect Of Temperature ◽  
Actual Condition ◽  
Coupling Mechanism ◽  
Mass Concrete ◽  
Finite Element Software

Thermal damage control of mass concrete is the key to guarantee the quality of mass projects. Based on several engineering experiences and finite element software ANSYS, the temperature field and stress field of the typical dam section of the Tengzigou hydropower station in Sichuan province were simulated. Considering the actual materials used, cooling measures, etc., maximum tensile stress and compressive stress at different time points derived from the temperature stress field during the time of concrete maintenance were calculated, and the numerical results showed that strength increment under the given conditions was much less than the actual condition. After the concrete of the dam body of the hydro power station were poured, there was no significant temperature stress crack appeared through a long-term observation, and the project condition was in tune with the calculated expectation. The above research results are valuable to further prediction of concrete temperature in different periods, the pre-study of the effect of temperature control measures, and these could offer guidance of the adjustment of temperature control measures in the case of abnormal conditions.

Temperature Cracks Controlling Technology for the Mass Concrete in Solid Sections of Lower Pylon Column

2013 ◽  
Vol 467 ◽  
pp. 262-269
Author(s):  
Fu Liang Gao ◽  
Yan Wei Fang
Keyword(s):  
Temperature Control ◽  
Thermal Stresses ◽  
Cooling Water ◽  
Control Measures ◽  
Mass Concrete ◽  
Removal Time ◽  
Control Scheme ◽  
Section Size ◽  
Circulating Cooling Water ◽  
Binder Ratio

According to the case that mass concrete in solid sections of lower pylon column of Jiashao Bridge was easy to crack in construction because of the bigger section size, larger content of cementitious material and lower water binder ratio, the temperature and thermal stresses distribution of mass concrete was simulated and temperature control scheme was adjusted constantly based on the results of field temperature monitoring. Through taking some temperature control measures such as applying circulating cooling water and prolonging the time appropriately, thermal insulation and moisture retention curing, extending the form removal time and controlling the quality of concrete, harmful cracks did not appear in solid sections of lower pylon column of Jiashao Bridge and anticipated temperature control requirements were achieved.

scholarly journals Pengaruh Jenis Material Pipa Pendingin Terhadap Distribusi Temperatur di Dalam Beton Yang Didinginkan dengan Sistem Post Cooling

2021 ◽  
Vol 1 (1) ◽  
pp. 14-23
Author(s):  
Ratnawati
Keyword(s):  
Cooling System ◽  
Water Discharge ◽  
Cooling Water ◽  
Concrete Surface ◽  
Heat Of Hydration ◽  
Mass Concrete ◽  
Cooling Pipe ◽  
Higher Temperature ◽  
Materials Used ◽  
Concrete Casting

Mass concrete is a concrete casting with a large enough volume, usually used for foundations, bridges,dams and so on. The heat of hydration in the mass concrete causes a temperature difference between the inside and the outside of the concrete surface. This can cause cracks in the concrete,where the temperature inside the concrete has a higher temperature rise than the outer surface yhat is in contact with the environment. One way to control the temperature of the concrete is to use a post cooling system.Post cooling system design requires knowledge of temperatur distribution in concrete. The research was conducted by varying the cooling pipe materials used,namely steel,PVC,and PEX where the cooling water discharge and temperatur were constant.The result of the research that have been carried out show that with the same cooling water discharge and temperature,concrete with PVC cooling has a higher temperature than PEX cooling pipe or steel.

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.

The Temperature Control Simulation on Concrete Dam Simulation Analysis of the Concrete Block in First-Stage Water Cooling

2012 ◽  
Vol 462 ◽  
pp. 402-406
Author(s):  
Ying Bin Kang ◽  
Hui Xia Bian
Keyword(s):  
Temperature Field ◽  
Temperature Control ◽  
Simulation Analysis ◽  
Control Measure ◽  
Cooling Water ◽  
Concrete Block ◽  
Water Cooling ◽  
Concrete Dam ◽  
Cooling Pipe ◽  
Concrete Temperature

Control the concrete temperature to reduce the temperature cracks is one of the main tasks in the concrete dam construction. Water cooling is the most effective temperature control measure of concrete dam. In connection with the concrete temperature field of cooled computational problems, according to the water and heat exchange between the concrete and cooling water pipes, The cooling pipe is considered as the effect source of heat, and the effect of the water cooling is considered on average meaning, and then the approximate temperature field can be obtained through the finite element.

Numerical Modeling and Simulation Analysis of Temperature Field of Disc Brake on Trains

2011 ◽  
Vol 199-200 ◽  
pp. 1492-1495 ◽  
Author(s):  
Guo Shun Wang ◽  
Rong Fu ◽  
Liang Zhao
Keyword(s):  
Temperature Field ◽  
Temperature Gradient ◽  
High Speed ◽  
Large Scale ◽  
Working Condition ◽  
Constant Speed ◽  
Brake Disc ◽  
Disc Brake ◽  
Brake Pad ◽  
Finite Element Software

The simulation calculation on the temperature field of the disc brake system on high-speed trains under the working condition of constant speed at 50Km/h is made. A steady-state calculation model is established according to the actual geometric size of a brake disc and a brake pad, and the analog calculation and simulation on the temperature field of the brake disc and the brake pad by using the large-scale nonlinear finite element software ABAQUS are carried out. The distribution rules of the temperature field of the brake disc and the brake pad under the working condition of constant speed are made known. The surface temperature of the brake disc at friction radius is the highest, with a band distribution for temperature. There exists a temperature flex point in the direction of thickness, of which the thickness occupies 15% of that of the brake disc; due to the small volume of the brake pad, the temperature gradient of the whole brake pad is not sharp, and larger temperature gradient occurs only on the contact surface.

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