Temperature Field Variation Law of Low Exothermic Polymer Grouting Material in Repairing Void Damage of Frozen Soil Subgrade

Zhang, Bei; Wang, Baolin; Zhong, Yanhui; Wang, Shuangjie; Li, Xiaolong; Wang, Shilun

doi:10.1155/2021/6670515

Cited by 4 publications

(3 citation statements)

References 33 publications

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“…Of these reaction types, the gel reaction refers to the curing reaction of the -NCO groups of the polyisocyanate and the -OH groups of the polyol, and the resulting urethane groups have an important influence on the strength of the rigid polyurethane foam (The reaction principle is shown in Figure 1). Foaming reaction refers to the reaction of -NCO groups of polyisocyanate and H2O to form CO2 and urea, which has an important influence on the production of foam (The reaction principle is shown in Figure 2) [20].…”

Section: Heat Sourcementioning

confidence: 99%

Experimental Study on Reducing the Heat of Curing Reaction of Polyurethane Polymer Grouting Material

Zhang,

Wang,

Zhong

et al. 2022

Prime Archives in Polymer Technology

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Polyurethane polymer grouting material has been effectively applied and promoted in the repair of road damages in nonfrozen areas. However, this material undergoes an exothermic reaction in the curing stage, which can cause a thermal disturbance in the frozen soil subgrade. To minimize the influence of the thermal disturbance of the polyurethane polymer grouting material in the repair of the frozen soil subgrade, an experiment was conducted to reduce the heat of the curing reaction under the influence of different proportions of a www.videleaf.com foaming agent, high-boiling point solvent, catalyst, and prepolymer. According to these test results, a proportioning scheme for the low exothermic polymer grouting material was formulated. The results indicated that the curing reaction temperature threshold of the polyurethane polymer grouting material was negatively related to the proportion of physical foaming agent (HCFC-141b) and high-boiling point solvent, and positively related to the proportion of water weight. In the three stages of rapid temperature rise, slow temperature rise, and constant temperature, the rate of the temperature rise of the low exothermic polymer grouting material was lower than that of the common polymer, and the curing temperature threshold was 30.34% lower at a value of 101 °C. At a density of 80 kg/m 3 , the compressive strength and tensile strength of the low heat release polymer grouting material were lower than those of the common polymer grouting material, thereby ensuring the excellent performance of polyurethane foam and providing a theoretical reference for the rapid repair of frozen soil roadbed diseases.

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Section: Heat Sourcementioning

confidence: 99%

Experimental Study on Reducing the Heat of Curing Reaction of Polyurethane Polymer Grouting Material

Zhang,

Wang,

Zhong

et al. 2022

Prime Archives in Polymer Technology

View full text Add to dashboard Cite

show abstract

“…Of these reaction types, the gel reaction refers to the curing reaction of the -NCO groups of the polyisocyanate and the -OH groups of the polyol, and the resulting urethane groups have an important influence on the strength of the rigid polyurethane foam (the reaction principle is shown in Figure 1). Foaming reaction refers to the reaction of the -NCO groups of polyisocyanate and H 2 O to form CO 2 and urea, which has an important influence on the production of foam (the reaction principle is shown in Figure 2) [18].…”

Section: Heating Principle Of Polyurethane Polymermentioning

confidence: 99%

Experimental Study on Reducing the Heat of Curing Reaction of Polyurethane Polymer Grouting Material

Zhang

Wang

Zhong

et al. 2021

Advances in Polymer Technology

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Polyurethane polymer grouting material has been effectively applied and promoted in the repair of road damages in nonfrozen areas. However, this material undergoes an exothermic reaction in the curing stage, which can cause a thermal disturbance in the frozen soil subgrade. To minimize the influence of the thermal disturbance of the polyurethane polymer grouting material in the repair of the frozen soil subgrade, an experiment was conducted to reduce the heat of the curing reaction under the influence of different proportions of a foaming agent, high-boiling point solvent, catalyst, and prepolymer. According to these test results, a proportioning scheme for the low exothermic polymer grouting material was formulated. The results indicated that the curing reaction temperature threshold of the polyurethane polymer grouting material was negatively related to the proportion of physical foaming agent (HCFC-141b) and high-boiling point solvent and positively related to the proportion of water weight. In the three stages of rapid temperature rise, slow temperature rise, and constant temperature, the rate of the temperature rise of the low exothermic polymer grouting material was lower than that of the common polymer, and the curing temperature threshold was 30.34% lower at a value of 101°C. At a density of 80 kg/m3, the compressive strength and tensile strength of the low heat release polymer grouting material were lower than those of the common polymer grouting material, thereby ensuring the excellent performance of polyurethane foam and providing a theoretical reference for the rapid repair of frozen soil roadbed diseases.

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“…Figure 1 shows the representative applications of polymer grouting material (PU) in civil engineering. As shown in Figure 1 (a), in the trenchless repairing of underground pipes 2,8 or roadbeds 9,10 , the two raw materials of PU, polyols and isocyanate, are directly injected into the cavities from the ground surface. The subsequently hardened PU can fill the space originally occupied by water or air.…”

Section: Introductionmentioning

confidence: 99%

Study on the shearing mechanical behavior and damage model of the polymer grouting material-concrete contact surface

Zhao

Chen

et al. 2022

International Conference on Smart Transportation and City Engineering (STCE 2022)

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The polymer grouting material (PU) has been increasingly used in trenchless repair of concrete pipes and roadbeds. Investigating the mechanical behavior of the PU-concrete (P-C) contact surfaces provides a basis for further evaluating the stability of the reinforced concrete structures, which, however, has not been conducted yet. In this study, based on the shear testing results, the mechanical properties and cracking characteristics of the P-C contact surfaces were investigated, followed by establishing the damage model. Results show that the cohesion force of the P-C contact surface increases from 0.42 MPa to 1.44 MPa when the density of the PU materials increases, and there exists residual strength when normal stress is applied. The shear failure of the P-C contact surface is caused by the shearing zone, of which the thickness is about 9-10 mm. The theoretical shear stress-strain curves of the P-C contact surfaces are in good agreement with the experimental ones. The maximum relative difference between the theoretical and experimental shear strength is about 4.2%, implying that the damage model can reflect the stress-strain laws of the P-C contact surfaces under shear.

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Temperature Field Variation Law of Low Exothermic Polymer Grouting Material in Repairing Void Damage of Frozen Soil Subgrade

Cited by 4 publications

References 33 publications

Experimental Study on Reducing the Heat of Curing Reaction of Polyurethane Polymer Grouting Material

Experimental Study on Reducing the Heat of Curing Reaction of Polyurethane Polymer Grouting Material

Experimental Study on Reducing the Heat of Curing Reaction of Polyurethane Polymer Grouting Material

Study on the shearing mechanical behavior and damage model of the polymer grouting material-concrete contact surface

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