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Fiber reinforced polymer composites (FRPCs) have gained great progress in a wide range of applications from construction and building structures to automobile and vehicle systems. During the operational lifetime, some FRPCs are exposed to various environmental conditions such as thermal cycles and thermal shocks. Fluctuation of the ambient temperature in the forms of thermal shocks or thermal cycles is one of the most important factors that deteriorate the durability and performance of the FRPCs. Compared to ceramic composites, less attention has been paid to the effects of thermal shocks and thermal cycles on the physical/mechanical properties of FRPCs. A comprehensive insight for the future advancements in this field is essential to possibly reduce the failure risks of FRPCs under thermal shocks and thermal cycles. The present work provides a comprehensive review on the physical/mechanical behavior of FRPCs under thermal cycles and thermal shocks. This work also provides a broad review on several factors that determines mechanical behavior of FRPCs, such as polymeric matrix, fiber type, incorporated nanofillers and fiber/polymer interface. Recent studies denoting important aspects and possible problems in mechanical performance of FRPCs under thermal shocks are also summarized. [ABSTRACT FROM AUTHOR]

Thermal behavior such as heat transfer is an important parameter for construction composites. Three-dimensional textile reinforced concrete (TRC) is one of the construction composites which is recently being used in the building industry. Therefore, in this study, the thermal behavior of three different TRC samples was investigated by a heat transfer test using an infrared method. The cementitious matrix was reinforced by 3D fabric with three different spacer yarn orientation angles. The cementitious matrix was fabricated by cement and waste stone powder. The TRC sample was put on the hot plate of the heat transfer apparatus and the temperature variations of the top surface of the sample were obtained. According to the test results, increasing the orientation angle of spacer yarns leads to a decrease in the thermal conductivity of the TRC sample and reduces heat transfer. On the other hand, a theoretical model was used to calculate the thermal conductivity and resistance coefficients of sandwich samples. Furthermore, a 3D finite element model was used to predict the heat transfer of TRC specimens. A unit cell of the TRC model was created in Abaqus software and finite element (FE) analysis was carried on a created model. Thermal conductivity and thermal resistance of samples according to FE results were calculated and compared with experimental results. FE results showed good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

In this research study, tubular geotextiles in the form of a braided structure have been used as a new type of geosynthetic for soil reinforcement. A series of standard plate load tests was conducted on unreinforced sand beds and sand beds reinforced with soil-filled tubular braided geotextile elements and planar geotextile layers to investigate and compare the performance of soil-reinforcing systems. The effect of embedded depth of the first reinforcement layer, the vertical spacing between layers, the length of reinforcement and the diameter of tubular geotextile elements on the behaviour of reinforced sand bed were investigated. The results showed that the application of horizontal tubular geotextile elements filled with soil could improve the ultimate bearing capacity and stiffness of the sand bed, and it could reduce the settlement significantly. The performance of the tube-shape reinforcement was much better than the planar reinforcement layers with similar material, properties, texture and areal density. Using tubular braided geotextiles in comparison with the similar planar layers resulted in an increase of ultimate bearing capacity and sand bed stiffness, and caused a significant reduction in the footing settlement. Overall, the tube-shaped geotextile having a braided structure proposes a strong potential as a novel soil-reinforcement material. [ABSTRACT FROM AUTHOR]

This study introduces the tubular braided structure as a new geosynthetic material for sand reinforcement. The performance of a tubular braid under the influence of similar soil–reinforcement interaction mechanisms has been investigated to emphasize the effect of the reinforcement form on the performance of the reinforced soil composite. For this purpose, three series of interaction element tests including direct shear tests, pull-out tests, and soil stress control tests were conducted on the unreinforced and reinforced sand. Finally, the overall performance of the reinforced foundation bed with the planar and tubular reinforcing textile (with similar materials, properties, texture, and areal density) was evaluated through a series of standard plate load tests. The results indicated that the performance of the sand-braid composite was better compared to the similar typical planar reinforcement, except for the case of pull-out test. Tubular braid resulted in the enhanced shear strength of the reinforced soil composites, mobilization of the excess compressive stress in the enclosed soil inside the tubular braids, reduction in the vertical stress level of the footing model transferred down through the soil bed, the increase of the average bearing capacity of the footing model, and a significant reduction in the footing settlement. [ABSTRACT FROM AUTHOR]

In this study, the effect of curvature on the flexural behavior of 3D integrated woven fabric composites was initially investigated. After optimizing the effect of curvature, two strengthening methods (thickening upper skin and foam-filling) were applied on curved 3D integrated woven fabric composites separately and simultaneously. Normalized-weight flexural properties were used as an efficiency index to analyze and compare the efficiency of both methods. Results showed that as curvature increases from 0 to 0.007 and 0.014 cm−1, peak load increases about 29.8 and 36.7%, respectively. In addition, as upper skin thickness increases, most of flexural properties increase and then decrease. Moreover, flexural properties improved by injecting polyurethane foam into the empty core. Furthermore, applying both methods on curved 3D integrated woven fabric composite sample made an outstanding improvement in flexural properties. That is, the flexural peak load, stiffness, and total energy absorption increased 244.4, 142.7, and 496.4%, respectively, in comparison to the unreinforced 3D integrated woven fabric composite sample. Based on the normalized results, it could be concluded that applying thickening upper skin and foam-filling the core methods separately have no considerable improvement in specific flexural properties; however, applying both methods simultaneously improved specific peak load and specific total energy absorption 35.3 and 134.1%, respectively. [ABSTRACT FROM AUTHOR]

In this study, the influence of 3D fabric on the flexural behavior of cementitious composites has been investigated. Three 3D fabric samples were produced with different spacer yarn orientation angles of 65°, 55°, and 47°. The cementitious matrix was fabricated by cement and waste stone powder. After casting of all samples, flexural test was carried out on all specimens. Results showed that cementitious sample reinforced by 3D fabric with less spacer yarn orientation angle proposed the highest flexural strength among all samples (reinforced and unreinforced samples). Moreover, finite element method was used to predict the flexural behavior of textile reinforced concrete. Finite element method results showed good agreement with the experimental data. Consequently, the maximum spacer yarn stress derived by finite element analysis was used to calculate the efficiency reinforcement factor for all the textile reinforced concrete samples. [ABSTRACT FROM AUTHOR]