Yahia A. Abdel-Jawad

• Ph.D
• Head of Faculty at Jordan University of Science and Technology

The feasibility of using locally available natural pozzolanic materials as complete replacement of cement binder to produce sustainable geopolymer concrete was investigated. Compressive strength, flowability, and microstructure of geopolymer mortar were measured and compared to highlight the effect of various parameters such as sand/pozzolan ratio,...

This paper presents a framework and methodology that facilitates implementing quality assurance principals at the field of Engineering Education. The focus is on delivering a “Semester Course Report” for all courses offered at the engineering school. The objective is to improve the quality of education, and to ensure sustainability of improvement a...

This paper presents the results of an experimental study to investigate the behaviour of structurally damaged full-scale reinforced concrete beams retrofitted with CFRP laminates in shear or in flexure. The main variables considered were the internal reinforcement ratio, position of retrofitting and the length of CFRP. The experimental results, gen...

The pore structure (i.e. total pore volume, surface area and pore-size distribution curves) was measured using mercury porosimetry and nitrogen sorption. Hydrated portland cement (type I) of water-cement (w/c) ratios 0.3, 0.4 and 0.6 by weight was analyzed at three degrees of hydration (i.e., 30%, 50% and 80%; 70% for the 0.3 w/c system) correspond...

Two modifications have been proposed for the Nurse–Saul maturity function to get better estimates of compressive strength of concrete cured at different temperatures. The modifications account for the effect of w/c ratio on the temperature dependence of strength development and the effect of curing temperature on the long-term strength. The effect...

The maturity concept has been widely used for decades as a proper approach for estimating the in situ strength of concrete at different ages and at different curing temperatures. Various maturity models and equations have been developed and proposed in the last three decades to be used in estimating the strength of concrete cured at different tempe...

Tests on steel tubular columns of square, rectangular and circular section filled with normal and lightweight aggregate concrete were conducted to investigate the failure modes of such composite columns. Thirty-six full scale columns filled with lightweight and normal weight aggregate concrete, eighteen specimens for each, were tested under axial l...

One of the major concreting problems in the Developing countries is the compaction of concrete. Several incorrect compaction procedures are followed during construction. These procedures often create problems in both fresh and hardened concrete. In its first part, the paper summarizes the author's site experience in the compaction of concrete. The...

An aggregate grading that yields maximum solid density and maximum particle interlock is highly desirable for both bound mixtures, such as asphalt concrete and plain and reinforced concrete, and for unbound mixtures such as those used in base courses. Maximum particle interlock leads to high strength. Whereas minimum voids in a certain material com...

An experimental investigation has been carried out to evaluate the effect of curing condition on the corrosion activity of the reinforcing steel in concrete. It has been shown that as long as the concrete is kept immersed in water, the passive film will not form. This may be due to the lack of oxygen at the interface of the steel and concrete. The...

The failure of laminated fibrous composite materials is predicted using six failure criteria: Abu-Farsakh and Abdel-Jawad criterion (AF-AJ), Tasi-Hill criterion (TS-H), Maximum Stress criterion (M-SS), Maximum strain criterion (M-SN), Petit-Waddoups (P-W), and Sandhu (SAN) criterion. Stresses and strains at failure for two fibrous composite laminat...

A micromechanical model is proposed to predict the tensile strength of unidirectional composite materials that have a fiber breakage. It is assumed that the load carried by the broken fiber is transferred eccentrically to the adjacent ones, which leads to a stress increase that would cause a reduction in the overall composite material tensile stren...

A rational model has been developed to determine the reference (neutral) surface positions for cross-ply fibrous composite materials having different behaviour in tension and compression. In this model, the actual bimodulus cross-ply (90°/0°) laminate is transformed into an equivalent material of single behaviour, tension or compression. Unlike oth...

The use of non-destructive tests to determine concrete properties such as compressive strength , modulus of elasticity and existence of cracks or other deterioration symptoms is quite popular. The concept of using the velocity of ultrasonic pulses through concrete as an indication of us quality has been one of the more attractive methods. An experi...

A simplified model to predict the ultimate drying shrinkage of concrete is introduced. The model is based on the theory of elasticity. Utilizing the mathematical formulation proposed by Almudaiheem, a computer program was written to provide values for the ratio of the shrinkage of concrete to the shrinkage of paste Rcp. A multiple regression analys...

An energy-based failure criterion has been recently developed by the authors. At any stress level, the model deals with the actual composite material as an equivalent linear elastic material. The total strain energy density of the system is considered to be composed of two parts, elastic and plastic. In this paper, the model has been used to identi...

An experimental program was performed on the combined effect of water and temperature on the compressive strength of sulfur concrete. Sulfur concrete samples were prepared, using three different types of aggregate, and immersed in water maintained at constant temperature of 20°, 40°, and 60° C for a period of one day up to 28 days. The compressive...

A new failure criterion based on the total strain energy density approach is introduced for an equivalent linear elastic material. The total strain energy is composed of the elastic strain energy and the plastic strain energy. The proposed criterion can be used to predict failure of fibrous composite materials subject to uniaxial, biaxial, or multi...

A novel analytical method developed by Mansour and Hussein has been used for the evaluation of critical thermal conditions for a non-linear inverse temperature distribution model of an explosive. The analytical results presented in this work have been compared with previously published numerical results and shown to be accurate. The advantage of th...