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.

No abstract

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.

The developed Strut-and-Tie Model (STM) has no unique shape for each load case of a given structural problem as long as the selected idealized internal load-resisting truss is in equilibrium with boundary forces, and also stresses in its components "struts, ties, and nodes" are within acceptable limits. However, the optimal shapes are the well-designed with best ordinal weight number of conditional factors as the rebar amount, the load factor, and the structural concrete ductility. The current study investigates numerically based on FE method stress flow contours and micro truss techniques many alternatives with different shapes of struts and ties that transfer the flow of forces from top of the deep beam with opening to both right and left supports. Then, these alternatives with different concrete characteristics are analyzed by strut-and-tie computational tools using different code provisions for verifying its results accuracy with the numerical nonlinear finite element analysis results for studying the structure performance under applied service loads and over loading till failure. The chosen alternative produce load factor to reach capacity greater than 1, therefore the strut-and-tie method always give demand collapse load lower than the true capacity collapse load. This implies that the solution obtained from STM usually lies on the safe side with conservative sense for concrete structures subjected to service loads. That's why the STM is emerging as an increasingly popular code-worthy methodology for the design and detailing of concrete structures D-Regions.