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The paper industry is one of the biggest sources of trash and stands out for its effects on both human health and ecological harmony. However, these waste could also help the building sector become more ecologically friendly. Beyond ecological considerations, modern construction often requires materials to make concrete durable, resisting heavy loads and less harmful environmental influences. This creates opportunities for waste management and practical application. This review provides a detail overview of eco-friendly construction ideas that deal with the practical use of materials that are often discarded (paper pulp ash). The impact they had on the characteristics of the construction material, the best mixture composition, and a discussion of the benefits and drawbacks of the “green” addition received the majority of the attention (paper pulp ash). The essential concrete properties such as consistency, setting time, flowability, compressive strength, flexural strength, tensile strength, and impact strength are reviewed. Furthermore, the cost benefits and environmental benefits of paper pulp ash as construction materials are also discussed. The study concludes by suggesting a line of inquiry for the creation of an environmentally friendly structural material for a sustainable future.

This study has been adopted to examine the effect of carbon fibre‐reinforced polymer (CFRP) sheet strengthening methods on the flexural behaviour of modified foamed concrete beams reinforced with different steel reinforcement ratios, and it deals with the enhancement in flexural behaviour of conventional nonstrengthened FC beams. Twelve modified foamed concrete beams were produced in three groups depending on the reinforcement ratio (under, balanced and over) and strengthened with externally bonded CFRP sheets applied in different methods (bottom layer, U jacket and hybrid). The examined flexural variables in four‐point bending were ultimate load, fracture mode, crack width, ductility, stiffness and deflection. The results showed an increase in the carrying capacity of foamed concrete beams strengthened with CFRP sheets by (2.5%–109%) compared to the reference nonstrengthened foamed concrete beams. The stiffness of the concrete samples reinforced with CFRP sheets were improved by 13%–306% compared to nonstrengthened foamed reference beams. For a given reinforcement ratio, it was found that the best CFRP sheets strengthening method was by applying the CFRP sheets in hybrid (wrap 0° + 90°). [ABSTRACT FROM AUTHOR]

Wood–plastic composites (WPCs) are materials that combine a polymeric phase with a filler, typically wood powder or fiber. This common practice significantly enhances certain mechanical properties of WPCs, such as tensile, compressive, and flexural strength, especially when coupling agents are added. Polyethylene terephthalate (PET) is a thermoplastic commonly used due to its high stiffness, mechanical strength, and chemical resistance. However, the increasing demand for PET has led to a rise in plastic waste accumulation, posing an environmental challenge. Therefore, recycling and promoting a circular economy are considered key strategies to reduce environmental impact and achieve sustainable development. The main challenge in WPC production lies in its formulation—specifically, determining the appropriate proportion of thermoplastic polymer, wood filler, and coupling agent. To optimize the mechanical properties of WPCs, it is necessary to vary these component proportions and understand how these changes affect the composite properties. This article describes a statistical approach for optimizing the mechanical properties of a WPC with PET as the polymer matrix. It is assumed that the mechanical properties of the WPC are a function of the proportions of the components that make up the mixture, so the optimization consists of determining these proportions in a way that maximizes the mechanical properties. With the experimental design, three models with inverse terms were fitted, which modeled the relationship between the component proportions and the flexural, compression, and tensile strength. The optimal formulation for maximizing flexural strength was found to be 58% PET, 39% wood, and 3% E‐GMA. The optimal formulation for maximizing compressive strength was found to be 58% PET, 40% wood, and 2% E‐GMA. The optimal formulation for maximizing tensile strength was found to be 86% PET, 11% wood, and 3% E‐GMA. The results are validated through analysis of variance of the mixture experimental design for mixtures. Finally, three response surface plots are presented for each mechanical property, which graphically describe the relationship between the different proportions of the mixture components and the mechanical properties. [ABSTRACT FROM AUTHOR]

The research work aimed at identifying the failure mode and energy evolution of damaged granite by uniaxial compression tests. The predamage specimens were prepared by cyclic loading with high confining pressure under constant upper and lower cyclic limit loading, which were collected from China. The test results showed that the cyclic loading with high confining pressure does damage to the rock to a certain degree. The macrocracks of predamage rock appear initially when the uniaxial compressive stress reaches 0.8 σmax. The failure mode is mainly mixed by shear failure and tensile failure. There is a critical state of the cyclic test that the predamage rock transforms the brittle deformation into a ductile one during the triaxial compression loading. Before the critical state, the average deformation energy of predamage rock is impacted by confining pressure (strongly, linear negative). The impact energy index and the residual energy of the predamage rock gradually decrease linearly with the increase of confining pressure. [ABSTRACT FROM AUTHOR]

In this research, the feasibility of strengthening and repairing two‐way reinforced concrete slabs and the effect of compressive strength on the properties of strengthened and repaired slabs using CFRP sheets were studied. The experimental program includes testing twelve samples. Four samples served as control panels, while four samples were strengthened using CFRP sheets to study the effect of carbon sheets on the ultimate load capacity. Also, the four pretested control panels were also taken and rerepaired using CFRP sheets and retested for the purpose of evaluating their properties after repair. The ultimate load capacity, energy dissipation capacity, initial stiffness, and failure pattern were explained by the experimental results obtained. The experimental results revealed that the use of CFRP strips led to an improvement in the average ultimate loading capacity by 16.2% and 6.45% for the strengthening and repairing system, respectively. Also, the utilization of the CFRP strips as a strengthening system significantly improved the stiffness and the cracking load of RC two‐way slabs. It was also noted that the ultimate loading capacity was proportionally related to the concrete strength for strengthened slabs with an increase of 23.3% for slabs with the highest concrete strength (C: 70). [ABSTRACT FROM AUTHOR]