Scientific Steps Group

A Review of Enhancing Performance and Sustainability of RC Shear Walls

September 24, 2023

Reinforced Concrete Shear walls are vertical components within a structure that are specifically engineered to counteract horizontal forces, such as those generated by wind or seismic activity. Their primary purpose is to enhance the stability and resilience of the building by redirecting these lateral forces to the foundation. This redirection effectively minimizes the building’s lateral movement during events like earthquakes or strong winds. Nowadays, building owners highly value the ability to ensure maintenance without incurring additional costs even in the face of major earthquakes. To achieve this, it’s crucial to reduce damage and maintain the reparability of structural elements. Multiple shear walls often bear heavy gravitational loads and remain susceptible to brittle breakdown due to shearing forces during lateral seismic loading. This susceptibility substantially increases the risk of a complete collapse of the entire shear wall system. The aim of this research paper is to comprehensively study and analyze various research endeavors concerning retrofitting methods employed to enhance the seismic resistance of new or pre-existing reinforced concrete (RC) shear. This analysis will include real-world case studies of examined structures. Moreover, this paper highlights the future potential and provides recommendations for effective retrofitting practices.

The Effect of Using Different Cross-Sectional Shapes of Steel on the Flexural Performance of Composite Reinforced Concrete Beams

September 2, 2023

Various types of structures can be constructed using reinforced concrete, including slabs, walls, beams, columns, foundations, frames, and more. The incorporation of structural steel and reinforcements in concrete enhances the strength and durability of structural elements while compensating for the tensile weaknesses in the concrete material. This study aimed to investigate the behavior of reinforced concrete beams utilizing structural steel of different shapes. Four types of concrete beams were prepared: a standard beam with normal reinforcement, and three composite beams, each featuring structural steel with different sectional shapes – T-section, I-section, and channel section. The consistent parameters included the cross-sectional area of the specimens, each measuring 100x150x450 mm, a steel reinforcement percentage of 2% of the total volume, and the compressive strength of the concrete. The conducted tests involved applying a concentrated load at the mid-span of each beam to examine the specimens’ behavior in terms of strength, flexural load capacity, deflection, crack patterns, and failure mode. The results of this study reveal that, given the same steel ratio, the load capacity of beams reinforced with structural steel of a channel shape has surpassed that of the other beams. Additionally, specimens with structural steel plates exhibited higher maximum deflections before failure compared to the beams with conventional reinforcement.

Bio-Concrete and Beyond Advancements in Self-Healing Techniques for Durable Infrastructure

August 16, 2023

Concrete is widely used in construction due to its durability and strength. However, structures made of concrete may weaken over time due to a variety of reasons, such as cracks, chemical attack, and environmental factors. This necessitates the development of new techniques to improve the lifespan and sustainability of concrete structures. Bio-concrete and self-healing techniques have emerged as viable approaches to address the challenges of concrete degradation. This literature review aims to provide a comprehensive overview of the advancements made in bio-concrete and self-healing technologies for concrete. The review begins by discussing the fundamental principles of bio-concrete, which is defined as the incorporation of bacteria or other microorganisms into the concrete matrix. These bacteria are capable of producing calcite precipitation, thereby sealing cracks and enhancing the concrete’s self-healing properties. Moreover, the review explores the mechanical and chemical characterization techniques used to assess the performance of bio-concrete as a self-healing concrete. It analyzes the results of various experimental studies and field applications that offer insights into the performance and effectiveness of these technologies under diverse environmental conditions. Overall, this literature review aims to consolidate the current knowledge and advancements in bio-concrete and self-healing technologies. The findings from this review can serve as a valuable resource for researchers, engineers, and practitioners involved in the design, construction, and maintenance of concrete infrastructure. This contribution ultimately promotes the development of more sustainable and durable concrete materials.

Sustainable Restoration Techniques for Historic Buildings in Tyre City

July 23, 2023

The intervention of historic buildings is a complex and evolving phenomenon; all aspects of sustainability must be considered. The possibility of these restored buildings collapsing can cause significant damage to the economy, social life, environment, and cultural heritage due to inappropriate interventions and decisions. Therefore, an integrated approach to managing these historic buildings is needed to achieve a sustainable level of restoration. The responsibility to transmit cultural heritage to future generations makes sustainable construction even more important. In this article, common types of interventions are analyzed to create a guide for an integrated approach to sustainability and structural behavior according to international standards and methods. As a case study, the city of Tyre (Sour) was analyzed, and several cases have been studied to highlight the necessary aspects for sustaining historic buildings. By considering all structurally or pathologically important aspects explained below in two sections—macro and micro approaches—this article presents the main sustainability methods and techniques.

An Experimental and Numerical Evaluation of the Structural Performance of Concrete Beams Containing Bamboo Shear Reinforcement

June 19, 2023

Alternatives to steel reinforcement in concrete are being actively investigated for environmental, economic, and durability concerns. Several studies suggest that bamboo is a potential substitute for steel reinforcement. In this study, the shear behavior of five reinforced concrete beams incorporating bamboo strips as shear reinforcement at different spaces and configurations were assessed. Structural concrete having a compressive strength of 25 MPa was used for this purpose. The experimental program involved applying four point bending test to the beams to determine their load deflection curves, crack pattern, and strain distribution. In addition, a numerical analysis was conducted for validation and prediction purposes. It was observed that including bamboo strips as shear reinforcement influenced a more brittle behavior with marginal differences when changing their spacing. On the contrary, the spacing was decisive for the load carrying capacity, as smaller spacing caused higher capacity. Strain distribution results followed a similar pattern to that of the deflection. All the curves exhibited a brittle shear failure evidenced by the crack propagation process. Further, the numerical study performed produced accurate results in comparison with the results obtained experimentally, in terms of both the load deflection curves and the crack pattern.