Fiber-reinforced polymer (FRP) rods are advanced composite materials with high strength, light weight, non-corrosive properties, and superior durability properties. Under severe environmental conditions, for concrete structures, the use of glass-fiber-reinforced polymer (GFRP) rods is a cost-effective alternative to traditional steel reinforcement. This study compared the flexural behavior of an OPC concrete slab with a high-volume fly ash (HVFA) concrete slab reinforced with GFRP rods/steel rods. In the fly ash concrete slabs, 60% of the cement used for casting the slab elements was replaced with class F fly ash, which is emerging as an eco-friendly and inexpensive replacement for ordinary Portland cement (OPC). The data presented include the crack pattern, load–deflection behavior, load–strain behavior, moment–curvature behavior, and ductility of the slab specimens. Additionally, good agreement was obtained between the experimental and nonlinear finite element analysis results using ANSYS 2022-R1. The study also compared the experimental moment capacity with the most commonly used design standard ACI 440.1R-15. This investigation reveals that there is a huge potential for the utilization of GFRP rods as reinforcement in fly ash concrete slabs.

Concrete structures provided with steel bars may undergo deterioration due to fatigue and corrosion, which leads to an increase in repair and maintenance costs. An innovative approach to eliminating these drawbacks lies in the utilisation of glass-fibre-reinforced polymer (GFRP) sheets as reinforcement in concrete structures instead of steel bars. This article relates to the investigation of the flexural behaviour of ordinary portland cement (OPC) concrete slabs and high-volume fly ash (HVFA) concrete slabs reinforced with bi-directional GFRP sheets. Slab specimens were cast with 60% fly ash as a replacement for cement and provided with a 1 mm-thick GFRP sheet in 2, 3 and 4 layers. The flexural behaviour of slabs reinforced with GFRP sheets was compared with that of the slabs reinforced with steel bars. Experiment results such as cracking behaviour, failure modes and load–deflection, load–strain and moment–curvature relationships of the slab specimens are presented. Subsequently, the nonlinear finite-element method (NLFEM) using ANSYS Workbench 2022-R1 was carried out and compared with the experimental results. The results obtained from the numerical investigation correlated with the experimental results. The experimental investigation showed that the HVFA concrete slabs reinforced with GFRP sheet provided a better alternative compared to the steel reinforcement, which led to sustainable construction.

Glass-fiber-reinforced polymer (GFRP) is an advanced material that has superior corrosion resistance, a high strength-to-weight ratio, low thermal conductivity, high stiffness, high fatigue strength, and the ability to resist chemical and microbiological compounds. Despite their many advantages compared with traditional materials, GFRP sections exhibit brittle behavior when subjected to severe loading conditions such as earthquakes, which could be overcome by infilling the GFRP sections with concrete. This paper presents the results of an experimental investigation carried out on the cyclic response of a GFRP beam-column infilled with high-volume fly ash engineered cementitious composites (HVFA-ECC) consisting of 60%, 70%, and 80% fly ash as a replacement for cement. Finite element analysis was also conducted using robot structural analysis software, and the results were compared with the experimental results. The mechanical properties of GFRP sections presented are the compressive strength of ECC, the direct tensile strength of ECC determined using a dog-bone-shaped ECC specimen, the hysteresis behavior of the beam-column, and the energy dissipation characteristics. The lateral load-carrying capacity of beam-column GFRP infilled with HVFA-ECC consisting of 60%, 70%, and 80% fly ash was found to be, respectively, 43%, 31%, and 20% higher than the capacity of GFRP beam-columns without any infill. Hence the GFRP sections infilled with HVFA-ECC could be used as lightweight structural components in buildings to be constructed in earthquake-prone areas. Also in the structural components, as 70% of cement could be replaced with fly ash, it can potentially lead to sustainable construction.

The construction industry is on the lookout for cost-effective structural members that are also environmentally friendly. Built-up cold-formed steel (CFS) sections with minimal thickness can be used to make beams at a lower cost. Plate buckling in CFS beams with thin webs can be avoided by using thick webs, adding stiffeners, or strengthening the web with diagonal rebars. When CFS beams are designed to carry heavy loads, their depth logically increases, resulting in an increase in building floor height. The experimental and numerical investigation of CFS composite beams reinforced with diagonal web rebars is presented in this paper. A total of twelve built-up CFS beams were used for testing, with the first six designed without web encasement and the remaining six designed with web encasement. The first six were constructed with diagonal rebars in the shear and flexure zones, while the other two with diagonal rebars in the shear zone, and the last two without diagonal rebars. The next set of six beams was constructed in the same manner, but with a concrete encasement of the web, and all the beams were then tested. Fly ash, a pozzolanic waste byproduct of thermal power plants, was used as a 40% replacement for cement in making the test specimens. CFS beam failure characteristics, load–deflection behavior, ductility, load–strain relationship, moment–curvature relationship, and lateral stiffness were all investigated. The results of the experimental tests and the nonlinear finite element analysis performed in ANSYS software were found to be in good agreement. It was discovered that CFS beams with fly ash concrete encased webs have twice the moment resisting capacity of plain CFS beams, resulting in a reduction in building floor height. The results also confirmed that the composite CFS beams have high ductility, making them a reliable choice for earthquake-resistant structures.

Fatigue life and residual strength prediction of various engineering components and structures are of primary importance because of economy and safety point of view. This article presents the fatigue life and residual strength of Carbon Fiber Reinforced Polymer (CFRP) composites at constant amplitude condition. Experiments were conducted on CFRP composites at different strain rates to determine its ultimate tensile strength. The lowest tensile strength resulting from different strain rates has been used as the ultimate tensile strength for carrying out the fatigue life and residual strength tests. A two-parameter wear out model for predicting the residual strength and the fatigue life of CFRP composites is proposed explicitly by accounting the effect of stress amplitude when the structure undergoes continuous loading. A model was also proposed to predict the fatigue life of CFRP composites based on the endurance limit. The proposed models show good agreement with the experimental results and with the available models in the literature.

This paper presents the fatigue behavior of Glass Fiber Reinforced Polymer (GFRP) composites at constant amplitude tension-tension loading conditions. A two parameter residual strength and fatigue life model has been proposed by accounting the effect of stress ratio when the structure undergoes continuous loading. A model is also developed to predict the fatigue life of GFRP composites based on fatigue endurance limit. Experiments were conducted on GFRP composite specimens to predict fatigue life and residual strength at various stress levels. Tests were also conducted to gain an understanding of the tensile behavior of GFRP composite specimens under different quasistatic strain rates. The lowest tensile strength resulting from strain rate studies has been used ultimately for conducting fatigue life and residual strength tests. Reliability of the proposed models has been verified with experimental results and with the models seen in literature.