Dineshkumar Gopalakrishnan

Sustainable materials and effective strengthening methods can contribute to the significant improvement of the structural performance and durability of reinforced concrete (RC) beams. 40% cement-fly ash replacement offers better sustainability and workability, whereas fibre reinforcement and external fibre reinforced polymer (FRP) wrapping are able to offer better strength and ductility. This paper is an experimental study where thirteen RC beams were studied, one of them being a conventional control beam, basalt fibre reinforced beam (BFRB) fibre contents of 0.5%, 1%, 1.5%, 2% and beams strengthened by applying E-glass fibre reinforced polymer (EGFRP) wraps, and glass fibre reinforced polymer (GFRP) wraps at 50, 75, 100, and 150 mm. In all mixes of concrete, fly ash was used as a partial replacement of cement (12.5%). The beams were tested to assess the load–deflection response, stiffness, ductility, cracking and failure modes. The mid-span deflections were determined analytically and the deflection was determined by the double integration method, which was compared to the experimental results. Basalt fibre content was found to result in much higher load-carrying capacity, stiffness, ductility and crack control than in the control beam, and a 1.5% of basalt fibre gave the best balance between strength and deformation capacity. A higher fibre dosage of 2.0% resulted in reduced performance due to fibre agglomeration. External FRP wrapping further improved beam performance, with closer wrapping spacings (50 and 75 mm) offering superior confinement and crack-bridging effects. GFRP wrapping consistently outperformed EGFRP, and the GFRP-wrapped beam with 1.5% basalt fibre and 100 mm spacing achieved the highest load capacity and deflection. As a whole, the obtained results showed that the concrete beams can be reinforced with the observed load conditions by applying the combination of fly ash, basalt fibres and external FRP wrapping.

This study examines the performance of reinforced concrete T-beams strengthened with PVCC nano layering and basalt fiber fabric wrapping. TP3, a PVCC nano-layered specimen with 1.2% PVA fiber, and TB2, a basalt fiber fabric-wrapped beam, outperform the other specimens. TP3 has a first fracture load of 112 kN and a maximum ultimate load of 165 kN, with 1.66 times the ductility and 1.51 times the stiffness of the control beam (T0). TP3 also has 1.61 times more energy absorption and the highest energy index, 1.46 times that of T0. TB2 can withstand a maximum ultimate load of 185 kN and has higher ductility, stiffness, energy absorption, and energy index than T0. The experimental results are validated by finite element analysis, which provides useful insights into strengthening procedures in structural engineering applications.

This study explores the effects of metakaolin (MK), fly ash (FA), superplasticizer, and banana and basalt fibers on concrete’s mechanical properties through a comprehensive experimental analysis. The materials employed include ordinary Portland cement (OPC) 53 grade, M-sand, coarse aggregates, 12.5% MK and FA, and superplasticizer (Sika at 0.5%), blended with banana and basalt fibers in varying proportions of 0%, 0.5%, 1%, and 1.5%. A total of 13 beam specimens, each measuring 1000 mm × 100 mm × 150 mm, were cast, including a control specimen. The primary focus of the study is to evaluate the mechanical behavior of the concrete beams under single-point load testing. Key parameters such as deflection, ductility, stiffness, energy absorption, and energy dissipation were examined. Among the various mixes, the combination with 1.5% basalt fiber and 12.5% MK (BSFM3) exhibited superior performance in terms of strength, stiffness, and overall mechanical properties. The study conducts a detailed microstructural analysis to understand the concrete mixes and performance. Comparative analysis with experimental results and existing literature underscored the enhanced performance of this mix and analyse the microstructural properties. These findings provide valuable insights for optimizing concrete mix designs, enabling engineers, architects, and construction professionals to create durable, sustainable structures.

This study evaluates the performance of PVCC (Polyvinyl Alcohol Cementitious Composite) layered beams (BP1 to BP5), basalt fiber fabric-wrapped beams (BB1 and BB2), and a control beam (B0). Results show that specimen BP3, with 1.2% PVA fiber in PVCC layered beam, and BB2, with basalt fiber fabric wrapped at the bottom up to the neutral axis, exhibit superior performance. BP3 delays first crack initiation, increases the ultimate load-carrying capacity by 19.87%, and achieves a remarkable 54.57% increase in maximum ductility compared to B0. BP3 also demonstrates 54.54% higher stiffness and notable energy absorption. Similarly, BB2 outperforms BB1 and B0 in first crack load, ultimate load carrying capacity, ductility, stiffness, energy absorption, and energy index. BB2 exhibits 2.10 times increase in ductility compared to B0. Incorporating PVA fiber in PVCC layered beams and basalt fiber fabric wrapping offers better improvements in crack resistance, load capacity, ductility, stiffness, and energy absorption, contributing to innovative and sustainable beam design in construction.

Fibres are added to concrete mixtures to enhance its performance. The introduction of fibres to concrete reduces brittleness while ensuring acceptable ductility

The use of calcined clay and coconut shell as a partial substitution for cement and coarse aggregate in concrete has been studied. The clay material is heated a

Maintenance Methodologies Embraced for Railroad Systems: A Review: Congestion on land, hike in fuel costs, and critical need to cut down environmental emissions have generated the urge to shift from conventional rail transit systems to metro rail and high-speed rail for a mass mode of transportation. The conventional railway network especially in India stages an effective space in the means of mass transit systems. Subsequently, periodic inspection of the state of railway tracks is vital for ensuring rail safety, as tracks are critical components of train transportation networks. Tracks are designed to withstand zero critical incidents, and with the advent of new high-speed train services, there is a greater need to focus on track performance. Track maintenance methods are customized to suit local conditions for enhancing safety and reducing disruptions while guaranteeing the resilience and sustainability of any rail system. In recent years, various aspects of the TMSs (track maintenance systems) have been introduced within the railway industry for both ballasted and ballastless track systems. This study reviewed various approaches to track maintenance measures using traditional methods, statistical methods, and geometry-based methods based on track deterioration. Among all the reviewed methods, track maintenance based on the geometry is said to cater to the needs of the maintainers. The outcomes of this study are expected to support and assist in track maintenance decisions in the railway industry.

Treatment of Tanning Effluent Using Seaweeds and Reduction of Environmental Contamination: One of the main sources of dangerous chemicals that are dumped untreated into land and water bodies and have a negative influence on the ecosystem are industrial effluents. Seaweeds are currently used for treating industrial effluent effectively. The technology is at a maturing stage. This paper reviews the characterization and cultivation of seaweeds for wastewater treatment. In this present study, different extracts of four seaweeds such as Gracilaria edulis, Sargassum wightii, Turbinaria ornata, and Kappaphycus alvarezii, from the Mandapam coastal regions were analyzed. The seaweeds are used to treat the leather industry effluents collected from EKM leather processing company, Erode, Tamil Nadu, India. Among all, extracts of Gracilaria edulis survived at different concentrations of TDS: 15,000, 25000, and 35000mg/l. Out of these different ranges, TDS of about 25000mg/l seaweed named Gracilaria edulis reduced more amounts of chemicals present in the effluent like TDS (93.90), phosphates (72.71), nitrate (75.08), nitrite (76.92), and turbidity (99.01) content. Additionally, we produce the quality and strength of agar gel from the cultivation of Gracilaria edulis by the Nikansui method. Finally, we got the extraction procedure to obtain a higher yield of about 10.26 and a maximum gel strength of 92.06gcm⁻² while maintaining the melting point at 78C.

To create cost-effective structures, the modern construction industry has sought to reduce the dead load of buildings. Lightweight concrete is a quick way to reduce dead load. The current study is primarily concerned with identifying modern substitutes for coarse aggregate likely to aid in waste management and offer potential alternatives to the most exploited natural resources. According to ACI C 39-M, this study developed a novel lightweight hybrid fiber-reinforced concrete (LWHFRC) with a density of less than 1825 kg/m³ and compressive strength of 50 to 75 MPa. Ordinary Portland cement (53 Grade) was mixed with fly ash, silica fume, and GGBS. Sintered fly ash aggregate (SFA) and palm oil shell aggregate (POS) were used as coarse aggregates. Hooked steel fibers and polyvinyl alcohol fibers were combined in a hybrid form to improve crack propagation properties at the initial and subsequent stages. The water-to-binder ratio was kept constant at 0.30 to 0.35 with a 1% superplasticizer. Four volume fractions of hybrid fibers (both steel and PVA with Vf = 0%, 1%, 1.5%, and 2%) were added. In addition, XRD, SEM, EDS, and EDS mapping tests were performed to finalize the material’s chemical composition and crystalline structure. Furthermore, beams and cylinders were tested to determine the modulus of rupture, which was determined to be between 9.5 and 14 MPa by ACI code C 1609-M, and indirect tensile strength, achieved as 10 to 14 MPa by ACI code C 496-M. The researcher altered the modulus of elasticity (Ec) formula for lightweight concrete and discovered a relationship between fc’ and fcb, fc’ and fspt, and fcb and fspt. Finally, ANOVA and regression tests were run to check the significance of the experiment. The cost analysis revealed that the cost of LWHFRC increased by approximately 16.46%, while the strength increased by 55.98% compared to regular concrete.

Nanotechnology is an emerging technology for the treatment of waste water. Nanoparticles have its own advantages as the higher surface area to volume ratio compared to the bulk material. In this study, zinc oxide‐based nanoparticles were synthesized. Synthesized nanoparticles are characterized by UV‐visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X‐ray spectroscopy (EDX). The antibacterial study was carried out using the synthesized nanoparticle. The photocatalytic degradation for methyl blue, methyl red, and Orange G is also done in this study using the synthesized nanoparticles. The shape and size of the nanoparticles obtained are rounding spherical with 80 to 110 nm. The optimum result obtained from the dye degradation study is 94% for methyl blue.