Fiber-reinforced concrete (FRC) has become one of the most promising construction techniques and repairing materials in recent times for the construction industry. Generally, plain concrete has a very low tensile strength and limited resistance to cracking prior to the ultimate load, which can be mitigated by the incorporation of fiber. Natural fibers have emerged as an appealing sustainable option in the last few decades due to their lower cost, energy savings, and minimized greenhouse effects. Areca fiber is one of the natural fibers that can be sourced from the waste-producing areca nut industry. Hence, this study aims to assess the mechanical, rheological, and micro-structural properties of areca fiber-reinforced concrete (AFRC). For this purpose, areca fiber was used in the concrete mix as a weight percentage of cement. In this regard, 1%, 2%, 3%, and 4% by weight of cement substitutions were investigated. As key findings, 2% areca fiber enhanced the compressive strength of concrete by 2.89% compared to the control specimen (fiber-free concrete). On the other hand, splitting tensile strength increased by 18.16%. In addition, scanning electron microscopy (SEM) images revealed that the cement matrix and fibers are adequately connected at the interfacial level. Energy dispersive X-ray spectroscopy (EDX) test results showed more biodegradable carbon elements in the areca fiber-mixed concrete as well as an effective pozzolanic reaction. The study also exhibited that adding natural areca fiber lowered the fabrication cost by almost 1.5% and eCO₂ emissions by 3%. Overall, the findings of this study suggest that AFRC can be used as a possible building material from the standpoint of sustainable construction purposes.

This study investigates the utilization of waste iron slag (WIS) as a sustainable alternative in concrete production to reduce environmental impact and preserve natural resources. The experimental investigation of WIS-incorporated concrete focused on compressive and tensile strength with machine learning (ML) models for prediction. Among the tested ML algorithms, Decision Tree (DT) and XGBoost showed the highest accuracy (R² = 0.95135) in predicting concrete strength properties, while models like SVM and Symbolic Regression underperformed. Experimental results indicate that up to 20 % WIS replacement maintains adequate strength, whereas higher proportions reduce structural integrity. A ranking score index and cost analysis confirmed the technical and economic feasibility of using WIS in concrete. Cost analysis demonstrated substantial cost savings with 25 % WIS incorporation, confirming its economic feasibility. Integrating experimental data with ML predictions highlights WIS's potential for sustainable concrete applications, enabling optimized mix designs and reduced reliance on physical testing. Future work should address limitations, including dataset expansion and the exploration of additional durability and mechanical properties to validate WIS's practicality in construction further.

Managing disposable waste surgical face masks and plastic made from polyethylene (PE) resin is a real challenge. Thus, these are considered a great threat to the environment. Generally, surgical face masks are made of microplastic made of polypropylene materials. Both polypropylene and PE are not easily decomposable in the soil. Consequently, the presence of these waste materials can have detrimental effects on terrestrial and aquatic ecosystems, exacerbating the ongoing crisis faced by the animal kingdom and the broader biosphere. Hence, it is imperative to identify alternate and efficient methods for waste management. Given its significant economic importance, the construction industry holds a prominent position among many industries globally. Consequently, waste masks within the construction sector might assume a crucial role in mitigating plastic pollution. Concrete, one of the most widely used construction materials, is being adapted with various waste materials as the partial or complete substitutes for natural constituents, such as cement and aggregates. This study focused on using different percentages of used COVID-19 surgical masks in fiber form and PE as partial replacements of natural coarse aggregates in producing sustainable concrete. Mask fibers were used in concrete production at percentages of 0%, 0.5%, 1%, 1.5%, and 2% of the total volume of concrete. Similarly, PE aggregates replaced the coarse aggregates by volume at 0%, 5%, 10%, and 15% in concrete. The results showed that the strength of concrete reduced as the percentages of mask fiber and PE aggregates increased. However, the strength and crack-bridging capability of mask concrete are still acceptable for some structural and non-structural applications. The results obtained from this research could also help engineers to design sustainable concrete materials with mask fibers.

Admixtures are an integral part of modern cementitious materials, as they significantly enhance the rheological, mechanical, and durability properties of the material. Though manufactured admixtures are mainly used in concrete production, they are expensive. Therefore, this research investigated the effect of sugarcane juice (SCJ), as a natural admixture, on the properties of concrete. Various percentages of SCJs were used to investigate the initial and final setting time, workability, compressive strength, and splitting tensile strength of concrete. Furthermore, the effect of different cement-sand ratios (c/s) and water-cement ratios (w/c) on the setting time of different cement mortar mixes was studied. Experimental results have shown that the setting time measured by the Vicat’s apparatus reduces significantly, up to a certain percentage of SCJ in the mortar mixes. Setting time is also reduced as the c/s and w/c ratios are reduced in the mortar mix. From the results, it was found that, based on the c/s ratio, with the addition of 20% SCJ in the mix, the initial setting time of mortar can be reduced to 10% from 79%. In the case of mechanical strength, compared to the control mix (0% SCJ), more than 29% higher compressive strength in concrete was achieved by adding 10% SCJ to the mix. For the splitting strength, this increment was more than 4%. The ANOVA analysis also proved that the higher percentages of SCJ produced a compressive strength that was not statistically different from the control concrete mix. Finally, the research outcome showed that the dosages of SCJ can greatly alter the setting time and mechanical strength of cementitious materials.

In this article finite element model is prepared for reinforced concrete beam which is flexurally held together by means of carbon fiber reinforced polymer laminate. The 3D analysis is conducted using ABAQUS software and the results are investigated, where maximum load, deflection at mid span and strain characteristics of both reinforcement and concrete are analyzed numerically. Later these parameters are investigated experimentally in a similar way by keeping all the important conditions such as loading, reinforcement detailing, boundary condition etc. identical. This comparative assessment illustrates that, the using of CFRP has a significant advantage to improve flexure behavior of RC beams. Various types of failure mode such as deflection and stress for whole cross section and for only reinforcement are achieved from finite element analysis. In addition, typical deflection, stress and strain contours of a specified node are found for unstrengthen and CFRP strengthened beam. This article also represents both the reinforcement strain values and concrete strain values for strengthened and unstrengthen RC beams and found a precise similarity while comparing with finite element modelling results. Furthermore, in terms of ultimate load, the deviation in result is as narrow as 4% for flexurally strengthened reinforced concrete beam by CFRP laminate. IUBAT Review—A Multidisciplinary Academic Journal, 6 (1): 13-24