INVESTIGATION OF THE EXPERIMENTAL AND NUMERICAL FLEXURAL BEHAVIOR OF INNOVATIVE TOTALLY ENCASED COMPOSITE BEAMS

Composite steel-concrete beams have been widely used in long span construction and high rise buildings due to their favorable behavior in terms of high strength, stiffness, and ductility. In this research, the flexural behavior of an innovative steel-concrete composite section is investigated experimentally and verified numerically using ABAQUS software. The studied section is composed of steel tubular specimen or steel hollow pipe totally encased in concrete in the absence of any flexural or shear reinforcement. Instead, steel mesh wraps are used around the tubular steel specimen to provide sufficient steel-concrete bond. All of the studied beams have the same 3m length and T-section dimensions to provide adequate comparison of results. The influence of using different percentages of steel mesh wraps around the steel specimen and the structural steel shape effect on the failure mode and ultimate flexural capacity were investigated. It was found that the ABAQUS model has provided excellent simulation of the flexural response of the studied beams with acceptable difference in results as compared to those obtained from experimental testing. Besides, the presence of steel mesh wraps at highly compressive damaged locations have prevented concrete spalling and crushing in these zones by ensuring sufficient steel-concrete bond

FLEXURAL TESTING OF VARIOUS COMPOSITE-BEAMSUNDER QUASI-STATIC LOADS

The successful interaction between concrete and steel has inspired researchers to develop composite structural systems. Steel and concrete are utilized in various configurations to reduce construction costs and assure optimal load-response behavior. Since the response spectrum of the composite system varies from one system to another, adequate understanding of the composite system behavior is essential to guarantee a desired response. Several parameters affect the flexural capacity and failure mode of a composite section, such as geometry, material properties and bond. In practice, advanced material mechanics and numerical modeling can be utilized for simulating section response, however, variability in the material response hinders accurate prediction. To serve as a benchmark and facilitate optimal composite section design, this paper presents a thorough experimental investigation of four types of composite beams under flexural loading. The first type represents reinforced concrete T-shaped beams confined by structural steel members. The second system comprises steel tubes filled with concrete. The third type consists of an open web steel joist encased in reinforced concrete. The fourth system represents rectangular shaped RC beams strengthened by steel plates. The results confirm the diversity of behavior of composite sections and reveal significant enhancement in the failure mode and flexural behavior as compared to control non-composite sections

BEHAVIOR OF CONCRETE MIXES USING RECYCLED AGGREGATE CONFINED WITH STEEL SECTIONS

Recycled Concrete Aggregate (RAC) is a form of recycled concrete that has been studied for green building for the past 50 years. It can be used to create strong structures, such as seismic retrofitting of earthquake-prone structures. Studies have attempted to experimentally study the effect of using recycled aggregate in concrete, but the literature lacks the use of recycled concrete aggregate rapped with steel rings. This study examines the behavior of circular concrete columns with different percentages of recycled aggregate. It examines the behavior of a column with different percentages of recycled aggregate, one without jacketing, one with partial jacketing, and one with full jacketing. The suggested approach is stimulated, and the samples are modeled using ABAQUS software to demonstrate a comparison between experimental and numerical analysis. The study on Behavior of Concrete Mixes Using Recycled Aggregate Confined with Steel Sections is pivotal for sustainable construction, conserving resources, and lowering carbon emissions. It also aligns with circular economy principles and compliance with sustainability regulations, fostering eco-friendly, cost-effective practices. Furthermore, the incorporation of jacketing and steel sections not only supports sustainability but also strengthens communities by enhancing earthquake and heavy load resistance, ensuring both environmental responsibility and the safety of structures in vulnerable regions. These results have to be adopted for their clear sustainability benefits, including resource conservation and waste reduction. Furthermore, the cost savings associated with using recycled aggregates make it economically attractive. Lastly, the enhanced mechanical properties of concrete contribute to more durable and resilient construction materials, aligning with both environmental, safety, and economic objectives

An overview of pavement maintenance management strategies in Malaysia

Pavement damages are always associated with its optimum function and considered among the main contributing factors to fatal accident. With significance growth of vehicular road traffic and of accompanying problems of overloading vehicles in Malaysia will indirectly contributed to worsen the condition. Unceasingly, road pavement will experience failures more rapidly than expected hence lead to negative socioeconomic effects. A proper and timely maintenance by road authorities must be made in order to sustain and maintain the roadway condition to keep them serviceable so that it will benefit not only safety but also improve economic growth and social development. Hence, this study was carried out to explore current practise of pavement maintenance strategies in Malaysia. To achieve that objective, a qualitative data of questionnaires distribution to industry practitioners that are involved in managing roads are analyzed to indicate the viability and practicability of pavement maintenance strategies in Malaysia. Other than that, specifics issue pertinent to pavement management also identified. The findings of this study are valuable in developing the realistic performance criteria for seamless road pavement maintenance strategies

Occupational safety and health assessment in metal industry within small and medium enterprise

According to annual report from the Social Security Organization (SOCSO) between years 2009 and 2011, metal industry has the highest reported number of accidents compared to the other manufacturing industry in small and medium enterprises (SMEs). Therefore, the aim of this study is to investigate the actual causes of problems that lead to the accidents involving metal industries within SMEs. In this study, checklist through site visits has been used to collect the data. The overall result reveals that the main causes of accident are due to organization failure, human factor, machine failure and surrounding environment

Current status of industrial accident learning in Malaysia

The accident rate in Malaysia is decreasing; however, statistically it is still high if compared with other developing nations. One of the reasons why accidents keep on happening is due to poor learning from accidents. This paper discusses the level of accident learning from accident reports submitted to the Department of Occupational Safety and Health (DOSH) Malaysia and the Society Security Organization (SOCSO) Malaysia involving 1,291 accident cases. Based on the quality and completeness of accident reports, their levels of learning were classified into five accident causation levels which are no, limited, fair, good and excellent learning

Statistical analysis of metalworking accidents within small and medium enterprises (SMEs) in Malaysia

Small and Medium Enterprises (SMEs) are known to be one of the major contributors to the national economy. However, in terms of occupational safety and health (OSH) implementation and performance, these SMEs, especially in the metalworking sector have yet to meet the necessary standard. This paper discusses the statistical analysis of accidents in metalworking industry by using accident reports submitted to the Department of Safety and Health (DOSH) and Social Security Organization (SOCSO) which involved 1635 accident cases. The main objective is to identify the real causes of accidents and recommend an appropriate action plan for accidents prevention at the workplace

Characterization of greater middle eastern genetic variation for enhanced disease gene discovery

The Greater Middle East (GME) has been a central hub of human migration and population admixture. The tradition of consanguinity, variably practiced in the Persian Gulf region, North Africa, and Central Asia1-3, has resulted in an elevated burden of recessive disease4. Here we generated a whole-exome GME variome from 1,111 unrelated subjects. We detected substantial diversity and admixture in continental and subregional populations, corresponding to several ancient founder populations with little evidence of bottlenecks. Measured consanguinity rates were an order of magnitude above those in other sampled populations, and the GME population exhibited an increased burden of runs of homozygosity (ROHs) but showed no evidence for reduced burden of deleterious variation due to classically theorized ‘genetic purging’. Applying this database to unsolved recessive conditions in the GME population reduced the number of potential disease-causing variants by four- to sevenfold. These results show variegated genetic architecture in GME populations and support future human genetic discoveries in Mendelian and population genetics