جامعة بلاد الرافدين - Bilad Alrafidain University - م.م محمد جلال عبدالله

م.م محمد جلال عبدالله

Asst. Lect. Mohammed Jalal Abdullah

تدريسي : قسم الهندسة المدنية

Teaching : DEPARTMENT OF CIVIL ENGINEERING

دكتوراه في الهندسة

PhD. in engineering

mohammedjalal@bauc14.edu.iq

Eng.mj96@hotmail.com

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المقالات داخل المجلة

البحوث

	2024	Buildings
Pultruded glass fiber-reinforced polymer (GFRP) materials are increasingly recognized in civil engineering for their exceptional properties, including a high strength-to-weight ratio, corrosion resistance, and ease of fabrication, making them ideal for composite structural applications. The use of concrete infill enhances the structural integrity of thin-walled GFRP sections and compensates for the low elastic modulus of hollow profiles. Despite the widespread adoption of concrete-filled pultruded GFRP tubes in composite beams, critical gaps remain in understanding their flexural behavior and failure mechanisms, particularly concerning design optimization and manufacturing strategies to mitigate failure modes. This paper provides a comprehensive review of experimental and numerical studies that investigate the impact of key parameters, such as concrete infill types, reinforcement strategies, bonding levels, and GFRP tube geometries, on the flexural performance and failure behavior of concrete-filled pultruded GFRP tubular members in composite beam applications. The analysis includes full-scale GFRP beam studies, offering a thorough comparison of documented flexural responses, failure modes, and structural performance outcomes. The findings are synthesized to highlight current trends, identify research gaps, and propose strategies to advance the understanding and application of these composite systems. The paper concludes with actionable recommendations for future research, emphasizing the development of innovative material combinations, optimization of structural designs, and refinement of numerical modeling techniques.

	2024	Results in Engineering
This study investigates the effect of continuous rectangular spiral shear reinforcement on reinforced concrete slabs under low-velocity conditions, crucial for scenarios such as landslides or vehicular collisions. By combining experimental and finite element analyses using ABAQUS, this research assesses the effectiveness of this reinforcement method. The experimental setup involves subjecting slabs to impact loading with consistent energy levels using a drop weight system. Various parameters, including acceleration time, strain-time in steel and concrete, and failure mode, are carefully monitored throughout the study. Results demonstrate a notable 216.13% improvement in energy absorption and a 43.70% increase in impact ductility compared to control specimens, reflecting higher rigidity and stiffness in spiral-reinforced specimens, as evidenced by elevated maximum acceleration values. Specimens with continuously rectangular spirals exhibit less severe surface damage upon complete failure, emphasizing their enhanced impact resistance. Diagonally arranged spiral reinforcements notably reduce damage, displacement, and stress. These findings highlight the significant potential of continuously rectangular spirals in improving the low-velocity behavior of reinforced concrete slabs, offering valuable insights for structural design and reinforcing systems. Additionally, using ABAQUS finite element analysis validates experimental findings, providing efficient insights into structural behavior under dynamic conditions.

	2023	PERTANIKA JOURNAL OF SCIENCE AND TECHNOLOGY
Concrete is the most widely used construction material in the world. It is now possible to construct structures out of concrete because this durable compound that consists of water, aggregate, and Portland cement not only gives us many scopes of design but also has a very high compressive strength at a low cost. This paper deals with alternative materials for the most common construction material, cement-based concrete and polymer concrete (PC), containing waste tin fibres. The study covers the fabrication of polymer concrete and the execution of three tests: compressive strength, flexural tensile, and splitting tensile. Tests were conducted to determine the mechanical properties of the PC, and the results were analysed and evaluated on several PC specimens with different ratios of waste tin fibre. The results showed that using waste tin as fibre reinforcement in PC would substantially enhance the overall mechanical performance. Specifically, the optimum amount of waste tin as reinforcement in PC was 0.16% for compressive and splitting tensile strengths, while 0.20% was the optimum fibre loading for the flexural tensile strength. In this case, a positive outcome was found at a constant resin-to-filler ratio of 40:60 by volume and a matrix-to-aggregate ratio of 1:1.35 by weight.

	2022	Construction and Building Materials
Bottom ash (BA) is a hazardous waste material from power plant. The well-graded BA can be a good sand replacement material in concrete. This study presents strength and thermal properties of concrete containing high calcium and water absorptive fine aggregate from well-graded BA as partial sand replacement (control mix (CM) 0%, BM5: 5%, BM10: 10%, BM15: 15%, and BM20: 20%). The workability of fresh concrete mixes was tested via slump test. The strength of the hardened concrete was assessed based on compressive strength, split tensile strength, and flexural strength. The thermal property was evaluated based on thermal conductivity test. The optimization of these model parameters was conducted via I-Optimal design. The workability of concrete mixes was reduced with an increase of well-graded BA due to high water absorption effect. The compressive strengths of all mixes reached more than 50% on 28th curing days with maximum strength by BM15 (49.0 MPa). The split tensile strengths showed one quadratic curve combining all mixes with maximum strength reached by BM10 (2.7 MPa). The flexural strength has slow growth exponential pattern with maximum strength by BM20 (6.0 MPA). The thermal conductivity values were steadily increased up to BM15 (2.44 W/mK) and reduced at BM20 (2.15 W/mK). The well-graded BA proportions (5 to 20%) were not showing any significant effect on the thermal properties. The optimised model of compressive strength has the highest accuracy with percentage errors below 5% compared to other parameters. The optimal well-graded BA as sand replacement material was BM10 giving 47 MPa compressive strength, 2.7 MPa split tensile strength, 5.3 MPa flexural strength, and 2.1152 W/mK thermal conductivity. The highest positive correlation coefficients were obtained between compressive strength and thermal conductivity (R2: 0.921). Thus, the well-graded BA improved the strength properties providing a sustainable supply in concrete technology.

	2023	Composite science
Concrete is brittle; hence, it is incredibly likely that concrete buildings may fail in both local and global ways under dynamic and impulsive stresses. An extensive review investigation was carried out to examine reinforced concrete (RC) slab behavior under low-velocity impact loading. Significant past research studies that dealt with experimental and numerical simulations and analytical modeling of the RC slabs under impact loading have been presented in this work. As a result, numerous attempts to define failure behavior and to assess concrete structures’ vulnerability to lateral impact loads have been made in the literature. Based on analytical, numerical, and experimental studies carried out in previous research, this article thoroughly reviewed the current state of the art regarding the responses and failure behaviors of various types of concrete structures and members subjected to low-velocity impact loading. The effects of different structural and load-related factors were examined regarding the impact strength and failure behavior of reinforced concrete slabs reinforced with various types of strengthening procedures and exposed to low-velocity impact loads. The reviews suggested that advanced composite materials, shear reinforcement, and hybrid techniques are promising for effectively strengthening concrete structures

	2023	Results in Engineering
"Reinforced concrete flat solid slabs may experience explosive and impact loads. Reinforced concrete flat solid slabs have been studied under static and dynamic loads. Researchers have widely explored numerous reinforcing strategies to strengthen RC slabs exposed to impact loads, yet gaps remain. Internal anchorage stirrups (W-stirrups shear reinforcement) is still rarely used to strengthen slabs against impact loading. Consequently, this study emphasized the influence of W-stirrups shear reinforcement on the dynamic response and failure modes of RC slabs subjected to impact loads. The first part examined the impact behavior of fully fixed RC flat solid slabs reinforced with W-stirrups shear reinforcement experimentally. Slabs were impacted using portable drop-weight testing equipment. Six 800-x-800-x-90-mm RC slabs were made. Three samples were reinforced with a W-stirrups orthogonally oriented in two directions, whereas three controls were without any type of strengthening. The eccentric vertical displacement of slabs, strain at four points on the W-stirrups, two on main steel, and two on concrete, and acceleration at one point over a slab were measured; also, failure modes were monitored. In the second section, ABAQUS software was used to generate finite element models of slab study samples. Numerical model results matched experimental results. Thus, the suggested finite element model may assess reinforced RC slabs under low-velocity impact loads. Finally, a parametric study was conducted in the third part to address the issue of over-reinforced design in slabs with W-stirrups. The parametric study aimed to determine the optimal steel ratio of flexural and shear reinforcement and its influence on the behavior of RC flat solid slabs reinforced with W-stirrups shear reinforcement."

	2024	Arabian Journal for Science and Engineering
Reinforced concrete slabs can be exposed to explosive and impact loads, prompting extensive research into their behavior under various static and dynamic loading conditions. Researchers have explored numerous techniques to enhance the structural integrity of these slabs when subjected to impact loads, but certain knowledge gaps persist. Particularly, the application of shear reinforcement, such as conventional stirrup shear reinforcement, to strengthen slabs against impact remains relatively uncommon. This study aimed to investigate the impact of conventional stirrup shear reinforcement on the dynamic response and failure modes of reinforced concrete slabs when subjected to low-velocity impact loading. The first phase involved experimental evaluation, focusing on the influence of vertical conventional stirrups as shear reinforcement in two-way, fully fixed RC slabs. Portable drop weight testing equipment was used to subject six (800 × 800 × 90 mm) RC slabs, to impact testing. Three slabs were strengthened with stirrups in two directions orthogonally configuration, while three control slabs received no additional reinforcement. Various parameters, including vertical displacement, strain at multiple points on the stirrups, main steel, and concrete, as well as acceleration at a specific point on the slab, were measured. Additionally, the failure modes were closely monitored. In the second phase, finite element models of the slab study samples were created using ABAQUS software. The numerical model results aligned with the experimental findings, indicating that the proposed finite element model can effectively assess the structural behavior of reinforced concrete slabs subjected to low-velocity impact loads. The third part of the research involved a parametric study to investigate the effects of bar diameter and drop position on the structural response of the slabs. The outcomes of this study highlight the significant positive impact of shear reinforcement, particularly in the form of conventional stirrups, on the load-bearing capacity of reinforced concrete slabs. Slabs with stirrups exhibited noteworthy improvements in strength, stiffness, and ductility compared to control specimens without shear reinforcement. Specifically, the presence of conventional vertical stirrup shear reinforcement increased the slab's capacity by 29.5% under the total impact energy until complete failure.

	2023	PERTANIKA JOURNAL OF SOCIAL SCIENCES AND HUMANITIES
"The use of cement is expected to increase over the years as the infrastructure continues to develop, and the needs to repair or rehabilitate an old and deteriorated building are necessary. However, many investigations have been conducted to establish promising polymer concrete applications in the last few decades. Meanwhile, using concrete in the construction industry has led to environmental issues. It is because relying on cement production in concrete will contribute to about 7% of the world’s carbon dioxide emissions. Therefore, polymer concrete was introduced in this study to minimise the use of cement in the industry. This research investigated the influence of different amounts of polypropylene (PP) fibre content on polymer concrete (PC) properties by determining the compressive strength, flexural strength and indirect tensile strength. Furthermore, the results of PC failure characteristics have been discussed. The polymer concrete specimens in this study have been cast into cylinders and prismatic specimens using PVC pipe and plywood formwork to determine the compressive strength, splitting tensile strength and flexural strength. By reinforcing PP fibre in the polymer concrete with a specific percentage of fibre reinforced, the overall strength of the polymer concrete"

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