A new method for hydraulic mass concrete temperature control: Design and experiment

Lu, Xiaochun; Chen, Bofu; Tian, Bo; Li, Yangbo; Lv, Congcong; Xiong, Bobo

doi:10.1016/j.conbuildmat.2021.124167

Cited by 17 publications

(6 citation statements)

References 27 publications

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“…Notably, the layered system significantly reduces peak temperature and maximum temperature difference, offering substantial time and cost economies, particularly when horizontal construction joints are well-handled. Furthermore, despite the merits of pipe cooling, including high cooling efficiency and ample cooling capacity, certain drawbacks persist, such as generating considerable temperature disparity around cooling pipes and rapid temperature decline during the later stages [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Heat of Hydration Analysis and Temperature Field Distribution Study for Super-Long Mass Concrete

Zhang,

Liu,

Liu

et al. 2024

Coatings

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In this study, the combination of ordinary cement concrete (OCC) and shrinkage-compensating concrete (SCC) was utilized to pour super-long mass concrete. The temperature and strain of the concrete were continuously monitored and managed actively after pouring. The investigation focused on the temporal and spatial distribution patterns of the temperature field, the temperature difference between the core and surface, and the strain evolution. Based on the constructed hydration exothermic model of layered poured concrete, the effects of the SCC, molding temperature, and surface heat transfer coefficient on the temperature field were analyzed. The results show that the temperature of super-long mass concrete rises quickly but falls slowly. SCC exhibits higher total hydration heat than OCC. The temperature field is symmetric along the length but asymmetric along the thickness due to varying efficiency of heat dissipation between the upper and lower parts of the concrete. After final setting of the concrete, the strain varies opposite to the temperature and peaks at −278 με. A few short cracks are observed on the end of the upper surface. Moreover, the numerical simulation results are in good agreement with the measured results. Increasing the molding temperature and surface wind speed increases the temperature difference between the core and surface. Conversely, increasing the thickness of the insulation layer is an effective way to curtail this difference. Thermal stress analysis is carried out and shows that lowering the molding temperature of SCC and increasing the thickness of insulation material can effectively reduce thermal stress.

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Section: Introductionmentioning

confidence: 99%

Heat of Hydration Analysis and Temperature Field Distribution Study for Super-Long Mass Concrete

Zhang,

Liu,

Liu

et al. 2024

Coatings

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“…It was found that the cooling-pipe system demonstrated a notable cooling effect, leading to a rapid and significant improvement in the bearing capacity of the pile foundation. Lu et al [24] embedded cooling pipes in the surface layer of the concrete structure and connected the cold and heat sources to achieve temperature control of the dam concrete. Wang et al [25] used numerical simulation analysis to determine the optimal pipe spacing of the cooling pipe system that was embedded in the concrete water tower, which controlled the temperature and thermal stress of the early-age water tower.…”

Section: Introductionmentioning

confidence: 99%

Study on Temperature Control and Cracking Risk of Mass Concrete Sidewalls with a Cooling-Pipe System

Chen,

Chen

2024

Buildings

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Hydration heat of early-age sidewalls can cause cracks owing to thermal stress, reducing the durability of underground space structures. The heat can be removed by the flowing water in the cooling pipe system. However, the cooling pipe may cause thermal stress due to the temperature gradient in the region adjacent to the cooling pipe, resulting in concrete cracking. To minimize the temperature peak of sidewalls and cracking risks in the region adjacent to the cooling pipe, the crack-distribution characteristics, temperature, and strain evolution of an early-age sidewall with a cooling pipe system are analyzed by concrete temperature and strain tests. Furthermore, a model that accounts for the early-age behavior of concrete and cooling-pipe effects is developed and solved. Finally, the effects of cooling-pipe parameters and ambient temperature on the sidewall’s temperature field and cracking risk are analyzed. The results indicate that the cracks emerge in the first two weeks after concrete pouring; most are vertical, and a few oblique cracks emerge in the wall corner. The tensile stress in the region adjacent to the cooling pipe gradually decreases along the flow direction. Reducing the water temperature and increasing the flow rate reduces the sidewall’s temperature peak and cooling rate. However, they increase the cracking risk in the region adjacent to the cooling pipe. When the flow rate exceeds 0.6 m3/h, further increasing the flow rate does not significantly affect the temperature field. Reducing the distance between cooling pipes reduces the temperature peak, cooling rate, and cracking risk in the region adjacent to the cooling pipe. In high-temperature environments, the cracking risk in the region adjacent to the cooling pipe increases significantly.

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“…Extensive research has been conducted on controlling the concrete temperature. On the basis of the heat balance equation, studies have been conducted on the selection of heat-tracing material specifications and the arrangement of structural measures, which are also used in winter concrete curing of floor slabs [13][14][15][16], grouting of prefabricated concrete connections in winter [17,18], concrete curing of subway stations in high-cold areas [19], and pouring and curing in mass concrete [20]. The studies have achieved good results in terms of temperature and concrete quality control.…”

Section: Introductionmentioning

confidence: 99%

Evolution and Parametric Analysis of Concrete Temperature Field Induced by Electric Heating Curing in Winter

Han,

Liu,

Zuo

et al. 2023

Sustainability

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Electric heat treatment is a widely used concrete curing method during the winter. Through direct and indirect heat exchange, the electric heating system tracks and controls the temperature of the heating medium based on a positive temperature coefficient (PTC) effect. In this study, to standardize the application of this treatment in the winter curing of concrete, the thermal energy conversion of an electric heating system and the heat-transfer characteristics of concrete have been studied. Based on the theoretical derivation, a calculation model of the relationship between the thermal energy of the electric heating system and the temperature of the concrete is established. The model is verified using the concrete heating and curing test results. The numerical analysis program COMSOL is used to analyze the effects of various factors on the concrete temperature field, including the electric heating power (e.g., the surface temperature of the electric heating system), concrete casting temperature, thermal conductivity, and heat release coefficient. The results show that decreasing the surface exothermic coefficient and increasing the heating temperature will significantly increase the peak temperature of the concrete. When the heat source temperature increases by 20 °C, the peak temperature could increase by approximately 13 °C. When the heating stops, the concrete volume increases temporarily, particularly in the region where the heating cable is buried. Consequently, an excessive heating power increase may cause cracks on the concrete surface. Compared with the factors of thermal conductivity and surface exothermic coefficient, the ambient temperature has the most significant effect on the concrete cooling rate when the heating stops. When the ambient temperature decreases by −20 °C, the cooling rate of concrete increases by 0.72 °C/h. The role of concrete insulation materials needs to be strengthened to reduce cooling rates during power outages and form removal. The findings from the study provide industry practitioners with a comprehensive guide regarding the specific applications of the electric heating system in early-age concrete curing.

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A new method for hydraulic mass concrete temperature control: Design and experiment

Cited by 17 publications

References 27 publications

Heat of Hydration Analysis and Temperature Field Distribution Study for Super-Long Mass Concrete

Heat of Hydration Analysis and Temperature Field Distribution Study for Super-Long Mass Concrete

Study on Temperature Control and Cracking Risk of Mass Concrete Sidewalls with a Cooling-Pipe System

Evolution and Parametric Analysis of Concrete Temperature Field Induced by Electric Heating Curing in Winter

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