Search

Construction using eco-friendly materials reduces environmental impact and promotes sustainable practices. This research uses sawdust and steel fibers to design sustainable concrete. The main goal is to improve mechanical properties and reduce embodied carbon emissions. This study examines the mechanical properties of concrete with different sawdust and steel fiber combinations to fill a gap in the literature. In this research synergistic effect of saw dust and steel fiber on concrete characteristics have been studied. The research also examines these pairings’ environmental benefits. This study used a response surface methodology (RSM) to design an experimental program and assess the effects of input variables (sawdust and steel fiber percentages) on output responses like compressive strength (CS), split tensile strength (STS), flexural strength (FS), modulus of elasticity (MOE), embodied carbon (EC), and eco-strength efficiency (ESE). Established testing methodologies and RSM provided an optimum prediction model based on specimen mechanical properties. Sawdust and steel fibers enhances concrete’s mechanical properties. Varying proportions of both materials were added in mix; sawdust (0%–12%) and steel fiber (0%–2%). The experimental findings suggest that the optimized composition achieved the following mechanical properties: 13.85 MPa compressive strength, 1.4 MPa split tensile strength, 3.67 MPa flexural strength, 18.027 GPa modulus of elasticity, 211.272 kg CO2e/m3 embodied carbon, and 0.065487 eco-strength efficiency. This research showed that the aims of improving mechanical properties and reducing embodied carbon were achieved. As per multi-objective optimization, optimal percentages of saw dust and steel fibers in concrete are 11.81% and 0.063% respectively. The investigation yielded many suggestions. To test the optimal blend composition of ecologically friendly concrete in real-world building projects, start with realistic projects. Finally, life cycle evaluations and cost studies are needed to determine the environmental and economic impacts of eco-friendly concrete compared to standard options.

The use of rubber aggregates derived from discarded rubber tyres in concrete is a pioneering approach to replacing natural aggregate (NA) and promoting sustainable building practices. Recycled aggregate in concrete serves the dual purpose of alleviating the accumulation of discarded rubber tyres on the planet and providing a more sustainable alternative to decreasing natural aggregate. Due to fact that the crumb rubber (CR) decreases the strength when used in concrete, incorporating titanium dioxide (TiO2) as a nanomaterial to counteract the decrease in strength of crumb rubber concrete is a potential solution. Response Surface Methodology was developed to generate sixteen RUNs which contains different mix design by providing two input parameters like TiO2 at 1%, 1.5%, and 2% by cement weight and CR at 10%, 20%, and 30% as substitutions for volume of sand. These mixtures underwent testing for 28 days to evaluate their mechanical, deformation, and durability properties. Moreover, the compressive strength, tensile strength, flexural strength and elastic modulus were recorded by 51.40 MPa, 4.47 MPa, 5.91 MPa, and 40.15 GPa when 1.5% TiO2 and 10% CR were added in rubberised concrete after 28 days respectively. Furthermore, the incorporation of TiO2 led to reduced drying shrinkage and sorptivity in rubberized concrete, especially with increased TiO2 content. The study highlights that TiO2 inclusion refines pore size and densifies the interface between cement matrix and aggregate in hardened rubberized concrete. This transformative effect results in rubberized concrete demonstrating a commendable compressive strength comparable to normal concrete.

Concrete has a great capacity to withstand compressive strength, but it is rather weak at resisting tensile stresses, which ultimately result in the formation of cracks in concrete buildings. The development of cracks has a significant impact on the durability of concrete because they serve as direct pathways for corrosive substances that harm the concrete’s constituents. Consequently, the reinforced concrete may experience degradation, cracking, weakening, or progressive disintegration. To mitigate such problems, it is advisable to include discrete fibres uniformly throughout the concrete mixture. The fibers function by spanning the voids created by fractures, therefore decelerating the mechanism of fracture initiation and advancement. It is not practical to assess the beginning and spread of cracks when there are uncertainties in the components and geometrical factors through probabilistic methods. This research examines the behaviour of variation of steel fibers in Fiber Reinforced Concrete (FRC) via Finite Element Method (FEM) modeling. In this study also the fracture parameters such as fracture energy, and fracture toughness have been computed through FEM analysis. The FEM constitutive model developed was also validated with the experimental result. The compressive strength of the developed constitutive model was 28.50 MPa which is very close to the 28-day compressive strength obtained through the experiment, i.e., 28.79 MPa. Load carrying capacity obtained through FEM was 7.9 kN, 18 kN, and 24 kN for three FEM models developed for three varying percentages of steel fiber 0.25%, 0.5%, and 0.75% respectively. The study developed a FEM model which can be used for calculating the fracture parameters of Steel Fibre-Reinforced Concrete (SFRC).

With an embodied carbon content of 0.93 kg CO2/kg, cement is an essential component of concrete. As the global demand for concrete construction is rising, research is being conducted to replace cement with supplementary cementitious materials (SCMs). A variety of SCMs are identified as having positive impacts on the concrete's compressive strength and embodied carbon. Coir Fibre Ash (CFA) is well known in SCM from existing research, but its use in concrete has not been investigated from an embodied carbon perspective before. The paper adopts an experimental methodology involving CFA as SCM at 3%, 6%, 9%, 12%, 15%, and 18% of 576 kg cement for each m3 of concrete. CFA was therefore added. The study aimed to find out the impact of the addition of CFA in concrete on compressive strength (CS), flexural strength (FS), splitting tensile strength (STS), and modulus of elasticity (MOE). The determination of embodied carbon was made, and RSM was used to develop the model with maximum accuracy. Samples were prepared for 7, 14, and 28 days. CFA was found to be positively affecting CS, FS, STS, and MOE till 9%, after which, because of the dominance of silica dioxide in CFA, it did not show any improvement. Embodied carbon was found to be decreasing with the increasing addition of CFA. RSM results followed by optimization provided highly validated equations for predicting the CS, FS, STS, and MOE of concrete by just using the value of CFA as SCM.