Field test study on early strain development law of mass concrete in cold weather

Mei, Yuan; Zhao, Lei; Nong, Xingzhong; Yang, Tao; Zhang, Xinyue; Wang, Rong; Wang, Xueyan

doi:10.1016/j.cscm.2022.e01455

Cited by 6 publications

(5 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Referring to the treatment of strain data by Yeon et al [34], all strain readings were zeroed to this turning point. The subsequent strain changes are basically opposite to those with temperature changes, with the maximum compressive strain occurring when the peak temperature is reached, which is consistent with the conclusions of the field experiment by Mei et al [35]. The maximum compressive strains of C1 and C3 occur at C1-2 and C3-2, respectively, with strain values of −156 µε and −278 µε.…”

Section: Strain Field Distributionsupporting

confidence: 89%

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

Zhang,

Liu,

Liu

et al. 2024

Coatings

View full text Add to dashboard Cite

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.

show abstract

Section: Strain Field Distributionsupporting

confidence: 89%

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

Zhang,

Liu,

Liu

et al. 2024

Coatings

View full text Add to dashboard Cite

show abstract

“…Many infrastructure projects and large-scale industrial and civilian buildings take several years to complete, and winter construction has become a necessary construction method in order to speed up the construction process and turn the entire year into an effective construction period [7]. However, during the winter, concrete has its own special and complex properties [8,9]. When the curing temperature is low, the strength of freshly poured concrete will increase slowly.…”

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

View full text Add to dashboard Cite

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.

show abstract

“…Concrete is the most popular construction material in use and is essential in civil engineering applications, such as infrastructures, buildings, bridges, and highways [ 1 , 2 ]. However, as an energy consumption material, the amount of concrete being used is growing every year; thus, how to extend the service life and reduce CO 2 emissions during the full life cycle of concrete is a crucial problem that needs to be solved [ 3 , 4 ].…”

Section: Introductionmentioning

confidence: 99%

Finite Element Analysis of Bonding Property and Flexural Strength of WUHPC-NC Gradient Concrete

Tian,

Ma,

Sun

et al. 2023

Materials

View full text Add to dashboard Cite

Ultra-high-performance concrete (UHPC) has greater mechanical and durability performance than normal concrete (NC). Using a limited dosage of UHPC on the external surface of NC to form a gradient structure could significantly improve the strength and corrosion resistance of the concrete structure and avoid the problems caused by bulk UHPC. In this work, white ultra-high-performance concrete (WUHPC) was selected as an external protection layer for normal concrete to construct the gradient structure. WUHPC of different strengths were prepared, and 27 gradient WUHPC-NC specimens with different WUHPC strengths and interval times of 0, 10, and 20 h were tested using splitting tensile strength to reveal the bonding properties. Fifteen prism gradient specimens with the size of 100 × 100 × 400 mm and a WUHPC ratio of 1:1, 1:3, and 1:4 were tested using the four-pointed bending method to study the bending performance of the gradient concrete with different WUHPC thicknesses. Finite element models with different WUHPC thicknesses were also built to simulate the cracking behaviors. The results showed that the bonding properties of WUHPC-NC were stronger with less interval time and reached the maximum of 1.5 MPa when the interval was 0 h. Moreover, the bond strength first increased and then decreased with the decline in the strength gap between WUHPC and NC. When the thickness ratios of WUHPC to NC were 1:4, 1:3, and 1:1, the flexural strength of the gradient concrete improved by 89.82%, 78.80%, and 83.31%, respectively. The major cracks rapidly propagated from the 2 cm position to the bottom of the mid-span, and the thickness of 1:4 was the most efficient design. The results simulated by finite element analysis also proved that the elastic strain at the crack propagating point was the minimum and was easier to crack. The simulated results were in good accordance with the experimental phenomenon.

show abstract

Field test study on early strain development law of mass concrete in cold weather

Cited by 6 publications

References 19 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

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

Finite Element Analysis of Bonding Property and Flexural Strength of WUHPC-NC Gradient Concrete

Contact Info

Product

Resources

About