The rapid growth of Natural Fiber Laminate (NFL) innovation is a direct response to environmental challenges, positioning these materials as superior alternatives to synthetic fiber composites. This paper delved into the outcomes of an extensive experimental study investigating the influence of sisal fiber (SLF), banana fiber (BF), and glass fiber (GF) on the mechanical and microstructural characteristics of concrete. The water absorption curves were established for sisal fiber concrete (SLFC), banana fiber concrete (BFC), and glass fiber concrete (GFC). Furthermore, Scanning Electron Microscope (SEM) observations were conducted to perform microanalysis and failure analysis of the tested specimens. The results revealed significant improvements in the concrete containing fibers compared to its counterpart in fiber-free concrete. For mixtures with a water-to-binder (W/B) ratio of 0.3, the most optimal mix (GF-30-135) showed improvements in compressive strength, flexural strength, and splitting tensile strengths by 4.13%, 8.93%, and 10.10%, respectively. On the other hand, for W/B of 0.4, mix GF-30-135 showed improvements of 5.05%, 8.55%, and 11.60%, respectively. Furthermore, as the fiber content increased, microscopic analyses revealed a weakening of the bond between the fibers and the rest of the matrix, contributing to the deterioration of the mechanical properties.

Waste materials pollution has instigated a serious environmental problem for decades, therefore new initiatives have been taken around the world to recycle wastes into construction materials in recent years. This study applied the compressive strength as one of the key parameters to examine the characteristics of materials, it was conducted to investigate the efficiency of adding different waste materials to cement mortar mixture as partial replacement with sand. Crumbed rubber, expanded polystyrene (foam), shredded wastepaper, and shredded plastic bags were selected to examine the efficiency of adding them to cement mortar. These waste materials were mixed individually with cement, sand and water proportionally. The produced mixture of each waste materials was casted in standard cubes and cured in water for different ages 3, 7 and 28 days. The compressive strength of the cured cubes was tested, the results showed that over all tested ages, plastic-based mortar provided the lowest compressive strength variance values by -7.4, -6.7%, and -5.4% in comparison with tested reference mortar. Rubber-based mortar showed the highest variance by -58.5 % at 3 days, -58.3% after 7 days and -55.5 % after 28 days. Foam comes next to Plastic-based mortar then Paper-based mortar by -13.7 & -37 % after 3 days, -11.3 & -34 % after 7 days and -14 & -26 % after 28 days respectively. In comparison to ASTM C129, the results ranges supported the possibility of using cement mortar mixed with shredded plastic, foam and shredded wastepaper in producing non-loadbearing concrete masonry units.

This study investigated the impact of varying steel fiber ratios by volume on the performance of HSC slabs. Incorporating steel fibers into high-strength concrete (HSC) has been shown to significantly enhance its mechanical properties, particularly by improving its load-bearing capacity. Furthermore, the addition of steel fiber reduces the reliance on traditional reinforcement bars, leading to a more efficient use of materials. This not only simplifies the construction process but also contributes to a reduction in overall construction costs. This study investigated the behavior of HSC slab specimens under loading and elevated temperatures. Three groups of specimens were created based on their thickness (8 cm, 12 cm, and 16 cm) using a single high-strength concrete mixture and four varying steel fiber proportions (0, 37.5, 75, and 150 kg/m³). Two-point monotonic loading was applied to each slab specimen until failure. To determine the splitting tensile strength, 12 cylinders were cast. Additionally, 84 cubes were cast to assess the effects of elevated temperatures and different cooling techniques on compressive strength (fcu). The results revealed that incorporating steel fibers into high-strength concrete slabs has a negligible effect on the concrete's density and compressive strength. However, it notably enhanced the splitting tensile strength and modulus of rupture. These improvements significantly boosted the material's resistance to cracking, making it more durable and better suited for applications requiring superior tensile performance. This is particularly important in structures subjected to dynamic or cyclic loading, where the risk of cracking and failure is greater. Doi: 10.28991/CEJ-2025-011-01-013 Full Text: PDF

This study aims to develop a sustainable alternative to Ordinary Portland Cement (OPC) by investigating the mechanical and structural properties of Ferrock concrete, an iron carbonate-based binder composed largely of industrial by-products. An experimental program was conducted, testing over 114 concrete cubes, 18 cylinders, and 6 full-scale reinforced concrete beams with Ferrock replacing OPC at 5%, 10%, 15%, 20%, and 25% by weight. The results demonstrate that a 15% replacement ratio yields a 25% increase in 28-day compressive strength, while splitting tensile strength improves consistently with Ferrock content. Most notably, reinforced beams with 20% Ferrock exhibited up to a 33% increase in flexural capacity, with failure modes shifting toward more ductile behavior and experimental capacities exceeding predictions from ACI 318, CSA A23.3, and Eurocode 2 by up to 62%. This research confirms that Ferrock is not only a carbon-negative material but also a technically superior partial replacement for OPC, offering enhanced strength, ductility, and structural performance for green construction applications.

This study aims to evaluate the flexural performance of semi-precast reinforced concrete slabs incorporating steel lattice girders as internal reinforcement. The objective is to investigate the influence of geometric and material parameters such as precast slab thickness, lattice girder height, top chord diameter, concrete compressive strength, and the addition of steel or glass fibers on overall flexural capacity and deformation behavior. Thus, previous studies have shown that replacing conventional cast-in-situ slabs with semi-precast systems can reduce total construction costs by 43–70%. Thirteen semi-precast slabs and one control slab were tested under four-point bending, and a nonlinear finite element model was developed in ABAQUS to simulate the experimental response. The analysis focused on load–deflection behavior, strain distribution, and failure modes. Results indicated that increasing slab thickness and chord diameter enhanced stiffness and load-bearing capacity, while higher concrete strength and fiber reinforcement improved crack control and reduced deflection. The FEM model demonstrated strong agreement with experimental results, validating its reliability for predicting structural performance. This study extends previous research by integrating a broad experimental parameter range with a validated ABAQUS finite element model, providing new insights into the structural optimization and cost efficiency of semi-precast slab systems. The proposed semi-precast system exhibited ductile behavior and achieved savings in formwork and labor cost compared with conventional flat slabs, offering a practical and sustainable alternative for efficient concrete construction.