Amr Ghoniem

Expanded Polystyrene (EPS) offers a viable pathway for balancing the fresh and hardened properties of infrastructure with environmental sustainability. This study evaluated six concrete mixes with varying EPS Styrofoam aggregate ratios and three water-to-binder (w/b) ratios, all of which incorporated silica fume and a superplasticizer. Eight machine learning (ML) algorithms (SVMs, GPR, ANNs, etc.) and a deep-learning LSTM model were utilized to preliminarily predict trends in EPS concrete properties. The experimental results indicated that the fine aggregate replacement outperformed the coarse aggregate replacement, retaining approximately 76% of the density of the control mixture, along with other property reductions. The fine aggregate replacement resulted in a compressive strength reduction of up to 46.4%, with losses in tensile strength of 20.9% and an improvement in workability of 3.4%. Finally, various Artificial intelligence (AI) models identified trends in the predictions of EPS properties based on the mixing ratio within a limited experimental dataset. In addition, explainable AI with SHAP analysis, quantifying feature contributions, ensured that the coarse aggregate replacement exerted a more significant negative impact on the mechanical properties and density than the fine aggregate replacement. Although these mixtures offer significant weight reduction, their use in structural applications requires further verification, as the reduction of nearly half of the compressive strength is significant. These findings provide strategies and a framework to facilitate the precise practical application of EPS concrete in nonstructural or lightly loaded applications.

Expanded Polystyrene (EPS) offers a viable pathway for balancing the fresh and hardened properties of infrastructure with environmental sustainability. This study evaluated six concrete mixes with varying EPS Styrofoam aggregate ratios and three water-to-binder (w/b) ratios, all of which incorporated silica fume and a superplasticizer. Eight ML algorithms (SVM, GPR, ANN, etc.) and a deep-learning LSTM model were utilized to preliminarily predict trends in EPS concrete properties, with SHAP analysis quantifying feature contributions. The experimental results indicated that the fine aggregate replacement outperformed the coarse aggregate replacement, retaining approximately 76% of the density of the control mixture, along with other property reductions. The fine aggregate replacement resulted in a compressive strength reduction of up to 46.4%, with losses in tensile strength of 20.9% and an improvement in workability of 3.4%. Finally, various AI models identified trends in the predictions of EPS properties based on the mixing ratio within a limited experimental dataset. In addition, SHAP analysis revealed that the coarse aggregate replacement exerted a more significant negative impact on the mechanical properties and density than the fine aggregate replacement. Although these mixtures offer significant weight reduction, their use in structural applications requires further verification, as the reduction of nearly half of the compressive strength is significant. These findings provide strategies and a framework to facilitate the precise practical application of EPS concrete in nonstructural or lightly loaded applications.

This study aims to quantify settlement uncertainty of strip footings on stabilized soft clay under multi-parametric variations to improve geotechnical foundation design. A three-dimensional numerical model was developed using ADINA to simulate full-scale strip footings resting on treated soft clay. Finite Element Analysis was conducted by systematically varying four governing parameters: footing width, treated soil thickness, treated extension width, and footing embedment depth. Parametric analyses were performed using normalized design ratios to evaluate settlement sensitivity and soil–structure interaction behavior. The results indicate that increasing the ratios of treated thickness to footing width, treated extension width to footing width, and embedment depth significantly reduces total settlement and enhances stress redistribution within the improved zone. Sensitivity assessment reveals that treated thickness and extension width are the most influential parameters in controlling settlement performance. The novelty of this research lies in quantifying settlement sensitivity through dimensionless design ratios within a unified numerical framework, providing a practical basis for optimizing treated zone dimensions. The findings contribute to a more efficient and sustainable foundation design by minimizing excessive material use while maintaining structural performance, offering economic and environmental benefits.

This paper presents an experimental study on how crumb rubber particles from waste tires and corrugated round steel fibers affect the mechanical behavior of concrete. In addition to the standard plain mix and five combinations of mixes composed of 0.5%, 1.0%, and 1.5% ratios, three steel fiber and crumb rubber mixes, 0.5%, 1.0%, and 2.0% weight of sand, coarse aggregate, cement, and silica fume were evaluated. The percentage of silica fume that replaced the weight of the cement in this study was 8%. The fresh properties of the 12 mixtures in terms of slump and density were studied. After 28 days of curing 36 cubes, 36 cylinders, and 12 prisms, the hardened properties were determined by evaluating the mean compressive, split, and flexural strengths. The results indicate that a synergetic effect is observed for the combination of crumb rubber and corrugated round steel fibers to improve the fresh and hardened properties of concrete. Adding fiber reinforcement to concrete can mitigate the negative impacts of rubber, and vice versa. According to the combination content, increases in compressive strength, tensile strength, and flexural strength of up to 49.04%, 38.60%, and 75.76%, respectively, were achieved compared with the control combination. This validates the applicability of the proposed mathematical prediction formulation to evaluate the compressive strength, split tensile strength, and modulus of rupture of rubberized fibrous concrete in terms of fiber and rubber ratios. Based on these results, a promising solution for tire disposal is to recycle waste rubber for fibrous concrete applications.

Concrete developed from light expanded clay aggregate (LECA) and glass fiber has good performance, durability, and sustainability. Towards this, the experimental investigation was designed to study cubes, cylinders, and simply supported beams. Four mixtures had LECA volume of 0%, 75%, 85%, and 95% as coarse aggregate replacement and glass fiber content volume of 2% (N, L75, L85, and L95), and the other two mixtures had 75% LECA and glass fiber content of 1% and 1.5% (L75-F1 and L75-F1.5). Results compared to normal concrete showed the weight reduction of samples while adding more glass fiber caused slump reduction in contrast to LECA. Increasing glass fiber volume in the mixture had a negative influence on tensile strength while causing compressive strength enhancement. Moment resistance and energy absorption capacity of L85 were enhanced by 7.5% and 10.3%, respectively. For L75-F1 specimens, the beam stiffness and ductility were enhanced by 14.8% and 14.3%, respectively.

The paper is motivated by real problems concerning the evaluation of the academic performance, satisfaction, critical thinking skills, and creativity in the learning process of engineering students exposed to a mixture of lecture‐based learning with competence‐based learning. The study randomized 450 students, enrolled in a reinforced concrete structures course, into three equal groups. One group was assigned to problem‐based learning, while project‐ and technology‐based learning was conducted for the other two groups. The practices of these three groups were compared based on two methods: monitoring of both generic and technical skills and a questionnaire analysis that indicated student satisfaction, critical thinking skills, and creativity. On the basis of the findings, the students who passed the project‐ and technology‐based assignments held the highest achievement marks and reported higher satisfaction, critical thinking skills, and creativity. The obtained results revealed the necessity of technology to embrace new learning strategies that mimic real‐world problems.

High-strength concrete incorporating macro-fiber combines high compressive strength of the matrix, strain-hardening, and multiple crack characteristics. Also, calcite sediment remediation bacterial techniques can enhance the mechanical properties, reduce concrete deterioration, and prevent corrosion of steel reinforcement in both the short-term and long-term. In this paper, The Bacillus subtilis bacteria at an optimum dosage of 105 cells/ml of mixing water was incorporated into M60 and M80 concrete strengthened with 0.5% macro synthetic-fiber content. The performance of 32 simply supported reinforced concrete beams with rectangular-section were evaluated numerically using ANSYS. In this study, the properties of matrix components are considered for different geometric sizes as slender and short beams with different longitudinal reinforcement ratios. The results showed that the bacterial participation in fibrous concrete beams had more significant enhancement in the initial cracking load, ultimate load, moment capacity ratio, ductility ratio, and flexural toughness compared to associated conventional concrete.

Fibers and bacterial additives in concrete have achieved significant success as a construction material. This paper presents the field of concrete self-repairing by introducing both Bacillus subtilis bacteria and polyethylene fiber as a dual-components. The main research goal is to reveal the principles of concrete self-repairing. At first, the research investigates the fiber-reinforced-concrete behavior, the concrete self-repairing process with the Bacillus subtilis bacteria for forming bacterial-concrete. And then, the study highlights the damage-repairing numerical simulation of fiber-reinforced-bacterial-concrete. The research shows the bacterial-concrete benefits to durability and mechanical properties besides to the polyethylene fiber assistance to enhance post-cracking tensile resistance and the pre-peak elastic modulus of concrete. The novelty of the fiber-reinforced-bacterial-concrete is the matrix combined improvement of both basic material properties and the post-cracking deflection capacity.