Bridging 3D-Printed and Cast Concrete: A Review of Mechanical Bond Behavior, Composite Action, and Sustainable Protective Structures

New possibilities in digital construction are made possible by the combination of 3D printed concrete with traditional cast concrete, which allows for the quick fabrication of hybrid structures that blend structural efficiency, customization, and geometric intricacy. The mechanical bond behavior and composite action at the interface between cast concrete and 3D printed concrete, however, continue to be significant obstacles influencing the overall performance, longevity, and structural integrity of such hybrid systems. In order to clarify the interfacial mechanisms driving load transmission, failure modes, and bond strength development, this thorough study examines current developments in experimental techniques and numerical modelling approaches. Additionally, the research examines how printing parameters, interface preparation methods, and reinforcing tactics can improve composite activity. At the same time, the assessment assesses the application and design of 3D printed concrete for protective constructions, such as—including blast-resistant barriers, disaster shelters, and impact-absorbing walls—highlighting their performance under extreme loading conditions. Through a comparative analysis of existing findings, we identify research gaps, standardization needs, and future directions for optimizing mechanical synergy in hybrid 3D printing systems. Visual summaries including comparative tables, bond stress–slip relationship charts, and schematic illustrations of interface mechanisms are provided to facilitate deeper understanding. This review contributes to the foundation for the next generation of high-performance, sustainable, and rapidly deployable concrete structures

Study of Silica Fume as a Mineral Admixture for High-Performance Concrete

Silica fume, a byproduct of silicon and ferrosilicon alloy production, has emerged as a key mineral admixture in the concrete industry due to its ability to enhance mechanical and durability properties . This study investigates the influence of silica fume on M20 grade concrete, replacing cement at 5%, 10%, and 15% levels. Compressive strength and workability tests were conducted on cube specimens, with results analyzed at curing periods of 7, 14, and 28 days. Given the ultrafine nature of silica fume, a superplasticizer was utilized to maintain workability. The experimental findings indicate a substantial improvement in compressive strength, with 10% replacement yielding the most favourable results as it is highlighting the suitability of silica fume in high-performance concrete applications

Advanced Pile Foundation Design for Disaster Resilience Using Best Worst Method and Computational Modeling

The load transfer behavior at the pile-soil interface is essential for ensuring the stability and resilience of pile foundations, particularly in disaster-prone regions. The allowable load a pile can bear depends on factors such as soil type, pile dimensions, and the in-teraction between the pile and surrounding soil, all of which are critical in maintaining structural integrity during seismic events, floods, and other natural disasters. This study investigates these complexities, proposing innovative approaches to accurately calculate load transfer and optimize disaster resilience strategies. An extensive review of three decades of literature identified six foundational studies on load transfer equations. Load-settlement curves were generated using Octave software, accommodating various soil types and pile dimensions commonly encountered in disaster scenarios. To refine calculations, codes were developed to compute allowable bearing loads using formulas from the Indian Standard code. A decision tree model implemented in Python further predicted the optimal calculation methods for specific conditions under disaster stress scenarios.Additionally, the research explored six distinct methods for evaluating allowable loads: Point by Point Curve, Cubic Root, Hiramaya Curve, Hyperbolic Curve, Krasinski Curve, and Root Curve. Among these, the Hiramaya Curve emerged as the most con-servative and reliable, offering a higher factor of safety due to its lower allowable load estimates. To enhance accuracy, weightages for each method were evaluated using the Best Worst Method, offering a systematic framework for prioritizing the methods based on their reliability and effectiveness. The findings revealed significant variations in load-bearing capacities across soil types and pile dimensions, emphasizing the necessity of site-specific designs. A novel code was also developed to streamline optimal load calculation methods, improving the efficiency, reliability, and disaster resilience of pile foundation designs. This comprehensive framework equips geotechnical engineers with adaptable tools and robust methodologies to design safer, more resilient structures across diverse geotechnical conditions

Design and Development of 3KGF Thrust Stand

This paper presents the design and development of a cost-effective, modular thrust stand capable of measuring up to 3 kgf of static thrust, tailored for testing electric propulsion systems in UAVs and drones. Utilizing accessible components like a 3 kg load cell, HX711 amplifier, 30A Hall effect sensor, and ESP8266 microcontroller, the system enables real-time wireless data acquisition for thrust, current, and power metrics. Ideal for academic and small-scale aerospace setups, the stand supports live monitoring, is easily modifiable, and lays the groundwork for advanced future testing such as torque, temperature, and multi-axis force analysis

Building Green Cities: Harnessing AI for Sustainable Urban Futures

The rapid pace of urbanization has intensified pressure on natural and built environments, necessitating sustainable solutions. Artificial Intelligence (AI) offers a promising approach for fostering eco-friendly urban growth. By integrating AI into urban planning and operations, cities can enhance energy efficiency, improve waste management, monitor environmental quality, and promote sustainable transportation. Drawing from data provided by sensors, IoT devices, and satellite imagery, AI generates insights that optimize city systems. In energy management, AI forecasts consumption, supports renewable integration, and reduces losses through smart grids. In waste management, it automates sorting, predicts waste volumes, and enhances recycling efficiency. Transportation also benefits, with AI enabling intelligent traffic systems that reduce congestion and emissions, while also improving public transit reliability. Additionally, AI supports the adoption of electric and autonomous vehicles and shared mobility services, decreasing urban transport’s carbon footprint. Environmental monitoring is another critical area, where AI analyzes real-time data to detect pollution and predict ecological risks, enabling proactive intervention. Urban planning also gains from AI’s ability to simulate development impacts, assess land use, and support policy decisions that preserve green spaces. However, challenges remain, including concerns about transparency, data security, access disparities, and implementation costs. Addressing these issues requires robust governance, equitable access to technology, and investment in skills development. In summary, AI has the potential to transform urban environments into greener, more efficient, and livable spaces. Realizing this potential will depend on sustained collaboration across sectors, ongoing research, and thoughtful policymaking

Design and Fabrication of Convertible Rods for Chair

Ergonomics is the study of how humans interrelate with their environment in which they do their physical work. Ergonomics is a very less discussed topic. Chairs is one of the major parts of the field of ergonomics. In this article, numerous papers were re- viewed and tried to explain the evolution of chairs. It has been found that new and innovative inventions in the field of chairs for providing maximum comfort to humans and detecting their wrong postures using various types of sensors and different types of fabrics were effective. It also proposed an idea of making chairs convertible, more efficient and taking less space

Thin-Walled Structures in Structural Engineering: A Comprehensive Review of Design Innovations, Stability Challenges, and Sustainable Frontiers

Due to their high strength-to-weight ratios and efficiency in material usage, thin-walled structures are a key part of modern structural engineering. Here we present a review of important developments in design innovations, stability issues, and sustainability. Finite element analysis, topology optimization, and AI techniques have revolutionized structural performance enhancement by optimizing load paths and re-distributing geometry for better structural stability. However, these advances do not render thin-walled structures immune to buckling, such as local, global and distortional failure. Complex failure mechanisms resulting from geometric imperfections and material properties require accurate predictive models and experimental validation. Diseased patients are excluded from multi-scale simulations, and their integration with aromatic heuristics to check robustness up to disease progresses are under current research. Sustainability is another crucial frontier, with emphasis on recycled materials, lightweight design, and energy-efficient manufacturing. Life-cycle assessment studies highlight the environmental benefits of these strategies, demonstrating reduced carbon footprints and resource consumption. These approaches not only improve sustainability but also enhance structural durability and cost efficiency. In future works, real-time design optimization using AI, hybrid fabrication processes through integration of additive manufacturing with traditional approaches, as well as smart materials with self-healing properties can be established further. This will be crucial to furthering the next generation of environmentally responsible, thin-walled structures that optimize structural performance. In summary, this review highlights the evolution of synergy between design, stability and sustainable development of thin-walled structures. The results offer some valuable guideposts to researchers and engineers, guiding the development of resilient, efficient, and eco-friendly structural systems

Research Article Mathematical Modelling and Bending Analysis of Beams

In this communication finite element formulation of Euler-Bernoulli beam is done considering Hermites shape functions and illustrated the calculation of stiffness matrix, mass matrix and force vector in detail. Here, considered the various cross-section of beams such as trapezoidal, rectangular, circular, triangular, etc under various loading and boundary conditions to investigate the effect of transverse deflection, shear force and bending moment with change in cross-section of beams by using finite element method based commercial software ANSYS 18.1. Here, present numerical results are validated with analytical results of beams with different cross-sections, loading and boundary conations

Performance of Concrete Materials Containing Recycled Aggregate from Construction and Demolition Waste in India

The recycling and reuse of waste concrete in India have gained significant momentum as sustainable construction practices are increasingly prioritized. This abstract provides a concise overview of the current state of recycling and reuse of waste concrete in India, with a focus on the relevant provisions of the Indian Standard (IS) codes. In-dia produces a substantial amount of construction and demolition waste, including concrete. The IS codes, such as IS 2386 Part 1:1963, IS 2386 Part 3:1963, and IS 456:2000, play a crucial role in guiding the testing, evaluation, and usage of recycled concrete materials. IS 2386 Part 1:1963 outlines testing procedures for aggregates, including recycled aggregates derived from waste concrete. These tests assess properties like particle size distribution, specific gravity, water absorption, and crushing strength to ensure the quality and suitability of recycled aggregates. IS 2386 Part 3:1963 provides methods for testing the compressive strength of concrete cubes made with recycled aggregates. This allows for evaluating the structural performance of recycled concrete. IS 456:2000, the Code of Practice for Plain and Reinforced Concrete, includes provisions for using recycled aggregates in concrete. It establishes maximum limits for replacing natural aggregates with recycled aggregates, ensuring the durability and strength of the resulting concrete. While the IS codes provide essential guidance, challenges remain, including awareness among stakeholders, standardized testing procedures, and the development of appropriate recycling infra-structure. In conclusion, adherence to IS codal provisions supports the recycling and reuse of waste concrete in India, promoting sustainable practices and contributing to a greener construction industry

Drinking Water and Gastrointestinal Diseases: A Systematic Review

Biological activity of human health depends on clean water. Obtain safe water and maintain sanitation are important in reducing disease transmission for public. Amongst Urban and Rural Water availability and poor hygienic practices are key concern as they play remarkable roles in the spread of water-based diseases. Environmental practice such as unhygienic water, poor sewage management and lack of sanitation encourages the breeding of mosquitoes and other forms of vectors within residential areas contribute to the increasing prevalence of waterborne diseases. This paper review well defines on waterborne diseases, its classification and the various practices apply in the bacteriological analysis of water