Preparation and photo-responsive behavior of reversible photochromic polyurethane cement composites

In order to solve issues related to bridge girders, expansion devices and road surfaces, as well as other structures that are prone to fatigue failure, a kind of fatigue-resistant elastic polyurethane concrete (EPUC) was obtained by adding waste rubber particles (40 mesh with 10% fine aggregate volume replacement rate) to conventional engineering polyurethane concrete (PUC). Based on the preparation and properties of EPUC, its constitutive relation was proposed through compression and tensile tests; then, a scanning electron microscope (SEM), an atomic force microscope (AFM) and a 3D non-contact surface profilometer were used to study the failure morphology and micromechanisms of EPUC. On this basis, four-point bending fatigue tests of EPUC were carried out at different temperature levels (−20 °C, 0 °C, 20 °C) and different strain levels (400 με~1200 με). These were used to analyze the stiffness modulus, hysteresis angle and dissipated energy of EPUC, and our results outline the fatigue life prediction models of EPUC at different temperatures. The results show that the addition of rubber particles fills the interior of EPUC with tiny elastic structures and effectively optimizes the interface bonding between aggregate and polyurethane. In addition, EPUC has good mechanical properties and excellent fatigue resistance; the fatigue life of EPUC at a room temperature of 600 με can grow by more than two million times, and it also has a longer service life and reduced disease frequency, as well as fewer maintenance requirements. This paper will provide a theoretical and design basis for the fatigue resistance design and engineering application of building materials. Meanwhile, the new EPUC material has broad application potential in terms of roads, bridges and green buildings.

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“…The preparation process of EPUC improved on the basis of previous studies, and it is shown in Figure 1 [19]. Figure 2 shows the content of EPUC.…”

Section: Preparation Of Reversible Photochromic Pucmentioning

confidence: 99%

Preparation and Mechanical-Fatigue Properties of Elastic Polyurethane Concrete Composites

Jia

Sun

et al. 2021

Materials

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“…Polyurethane is generally defined as the polymer compound containing repeated polyurethane bond structure units -[-NH-CO-O-]- on the polymer backbone [ 22 ]. The polyurethane structure is -[-CO-NH-R-CO-O-R-O-]n-, usually formed by the polymerization of a binary or polyisocyanate with two or more active hydroxide compounds through a stepwise polymerization.…”

Section: Methodsmentioning

confidence: 99%

Flexural Behavior of Polyurethane Concrete Reinforced by Carbon Fiber Grid

et al. 2021

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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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“…Due to the different types of microcapsules, the composite cement presents different colors and different discoloration temperatures, as shown in Figure . Jia used a simple drop-coating method to deposit photochromic sol–gel materials on the surface of polyurethane cement (PUC) to obtain smart coatings with photochromic and UV-resistant properties. The results show that the PM concentration has a significant effect on the photochromic performance.…”

Section: Applicationmentioning

confidence: 99%

Minireview on Application of Microencapsulated Phase Change Materials with Reversible Chromic Function: Advances and Perspectives

Zhai

Peng

2022

Energy Fuels

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Microencapsulated phase change materials (MEPCMs) have been widely used in the fields of slurry, buildings, and textiles, because of their excellent durability, impermeability, and high thermal conductivity. However, the microencapsulation also makes the phase change process difficult to observe. In recent years, many scholars have attempted to add chromic materials into microcapsules in order to realize the visualization of the phase change process. This paper gives a brief review of extant chromic MECPMs and their applications. Three main types of chromic materials were introduced: thermochromic, photochromic, solvatochromic. Their specific classification and chromic principle are shown. The commonly used preparation method of chromic MEPCMs was presented. The current advance in applications of chromic MEPCMs are briefly discussed. The discussion covers several frontier areas of focus, including thermal control fabric, energy-efficient buildings, wearable temperature sensors, and low-temperature energy storage. A detailed analysis about the application effect and potential of chromic MEPCMs in these areas was given. This Review may provide a guideline for the future study about preparation and application of chromic MEPCMs.

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Preparation and photo-responsive behavior of reversible photochromic polyurethane cement composites

Cited by 11 publications

References 28 publications

Preparation and Mechanical-Fatigue Properties of Elastic Polyurethane Concrete Composites

Preparation and Mechanical-Fatigue Properties of Elastic Polyurethane Concrete Composites

Flexural Behavior of Polyurethane Concrete Reinforced by Carbon Fiber Grid

Minireview on Application of Microencapsulated Phase Change Materials with Reversible Chromic Function: Advances and Perspectives

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