Preparation and Mechanical-Fatigue Properties of Elastic Polyurethane Concrete Composites

In view of the problems of traditional repair materials for anchorage concrete of expansion joints, such as ease of damage and long maintenance cycles, the design of polyurethane concrete was optimized in this article, which could be used for rapid repair of concrete in anchorage zone of expansion joints. A new type of carbon fiber grid–polyurethane concrete system was designed, which makes the carbon fiber grid have an excellent synergistic effect with the quick-hardening and high-strength polyurethane concrete, and improved the flexural bearing capacity of the polyurethane concrete. Through the four-point bending test, the influence of the parameters such as the number of grid layers, grid width, and grid density on the flexural bearing capacity of polyurethane concrete beams was tested. The optimum preparation process parameters of carbon fiber grid were obtained to improve the flexural performance of polyurethane concrete. Compared with the Normal specimen, C-80-1’s average flexural strength increased by 47.7%, the failure strain along the beam height increased by 431.1%, and the failure strain at the bottom of the beam increased by 68.9%. The best width of the carbon fiber grid was 80 mm, and the best number of reinforcement layers was one layer. The test results show that the carbon fiber grid could improve the flexural bearing capacity of polyurethane concrete. The carbon fiber grid–polyurethane concrete system provides a new idea for rapid repair of the anchorage zone of bridge expansion joints, and solves the problems such as ease of damage and long maintenance cycles of traditional repair materials, which can be widely used in the future.

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“…Aggregate gradation: AC-10 fine-grained concrete typical gradation [ 23 ] and the specific particle size and ratio are shown in Table 2 .…”

Section: Methodsmentioning

confidence: 99%

“…The technical parameters of reinforced materials are shown in Table 4. (3) Aggregate gradation: AC-10 fine-grained concrete typical gradation [23] and the specific particle size and ratio are shown in Table 2. [24].…”

Section: Preparation Of Experiments Materials 211 Test Substrate and Reinforced Materialsmentioning

confidence: 99%

Flexural Behavior of Polyurethane Concrete Reinforced by Carbon Fiber Grid

et al. 2021

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“…A method for predicting the fatigue life of polyurethane concrete was proposed, which can effectively describe the fatigue life and fatigue limit of polyurethane concrete. Jia et al [28] prepared fatigue-resistant elastic polyurethane concrete by adding rubber to polyurethane concrete.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Interfacial Bonding Properties of Polyurethane Concrete and Cement Concrete/Steel Reinforcement

Wang

Sun

Ding

et al. 2022

Advances in Materials Science and Engineering

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To solve the problem that the repair material of the bridge's expansion joint anchorage area is prone to debonding from the other bridge components, polyurethane concrete was designed and prepared, and the bonding performance of polyurethane concrete was tested by the bond splitting test, bond direct shear test, bond oblique shear test, and steel reinforcement pull-out test. The results show that the interfacial bond strength of polyurethane concrete and cement concrete can be improved by increasing the interfacial roughness. The bond splitting strength increases by up to 91.4%, the bond direct shear strength increases by up to 55.2%, and the bond oblique shear strength increases by up to 28.9%. The bond strength between polyurethane concrete and cement concrete are minimally influenced by temperature. An increase in the diameter of the reinforcement or the length of the bonded anchorage can increase the ultimate pull-out strength of the polyurethane concrete and the steel reinforcement. Polyurethane concrete is a novel composite material with excellent bonding performance with cement concrete and steel reinforcement, which can be widely used in practical projects, such as repairing bridge expansion joint anchorage areas in the future.

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“…A bottom-up approach based on the uses of recovered waste PUF: the technical properties required for polyurethane for specific applications were evaluated. Three promising solutions for the valorization of waste PUF were found: application as sorbent material for oil spills [ 10 , 11 , 12 ]; additive for construction materials as lightweight mortars or insulant materials [ 13 , 14 , 15 , 16 ]; application in filters for the adsorption of pollutants from wastewater [ 17 , 18 ].…”

Section: Introductionmentioning

confidence: 99%

Recovery of Waste Polyurethane from E-Waste—Part I: Investigation of the Oil Sorption Potential

Santucci

Fiore

2021

Materials

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The shredding of end-of-life refrigerators produces every year in Italy 15,000 tons of waste polyurethane foam (PUF), usually destined for energy recovery. This work presents the results of the investigation of the oil sorption potential of waste PUF according to ASTM F726–17 standard. Three oils (diesel fuel and two commercial motor oils) having different densities (respectively, 0.83, 0.87, and 0.88 kg/dm3) and viscosities (respectively, 3, 95, and 140 mm2/s at 40 °C) were considered. The waste PUF was sampled in an Italian e-waste treatment plant, and its characterization showed 16.5 wt% particles below 0.71 mm and 13 wt% impurities (paper, plastic, aluminum foil), mostly having dimensions (d) above 5 mm. Sieving at 0.071 mm was applied to the waste PUF to obtain a “coarse” (d > 0.71 mm) and a “fine” fraction (d < 0.71 mm). Second sieving at 5 mm allowed an “intermediate” fraction to be obtained, with dimensions between 0.71 and 5 mm. The oil sorption tests involved the three fractions of waste PUF, and their performances were compared with two commercial oil sorbents (sepiolite and OKO-PUR). The results of the tests showed that the “fine” PUF was able to retain 7.1–10.3 g oil/g, the “intermediate” PUF, 4.2–7.4 g oil/g, and the “coarse” PUF, 4.5–7.0 g oil/g, while sepiolite and OKO-PUR performed worse (respectively, 1.3–1.6 and 3.3–5.3 g oil/g). In conclusion, compared with the actual management of waste PUF (100 wt% sent to energy recovery), the amount destined directly to energy recovery could be limited to 13 wt% (i.e., the impurities). The remaining 87 wt% could be diverted to reuse for oil sorption, and afterward directed to energy recovery, considered as a secondary option.

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Preparation and Mechanical-Fatigue Properties of Elastic Polyurethane Concrete Composites

Cited by 19 publications

References 24 publications

Flexural Behavior of Polyurethane Concrete Reinforced by Carbon Fiber Grid

Flexural Behavior of Polyurethane Concrete Reinforced by Carbon Fiber Grid

Investigation of Interfacial Bonding Properties of Polyurethane Concrete and Cement Concrete/Steel Reinforcement

Recovery of Waste Polyurethane from E-Waste—Part I: Investigation of the Oil Sorption Potential

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