Mohammed Salem Alansari

• Doctor of Philosophy
• Associate Pofessor at Qatar University

This paper presents an analytical method for generating the interaction diagrams of uniaxially reinforced concrete (RC) columns that are subjected to four-face heating. Twenty-one (21) specimens obtained from previous case studies that were subjected to four-face heating (with different fire test times ranging from 63 to 356 fire minutes) are used...

This study reports the statistical significance of using Graphene Oxides (GOs), Graphene Nanoplatelets (GNPs) and Carbon Nanotubes (CNTs) on the mechanical properties of cement paste. Samples containing several nanoparticles' weight fractions were prepared and tested for flexure and compression. The testing results were then statistically analysed...

This study reports the statistical significance of using Graphene Oxides (GOs), Graphene Nanoplatelets (GNPs) and Carbon Nanotubes (CNTs) on the mechanical properties of cement paste. Samples containing several nanoparticles' weight fractions were prepared and tested for flexure and compression. The testing results were then statistically analysed...

This paper is a continuation of a previously published paper on this issue that studied the microencapsulation of calcium nitrate in urea-formaldehyde shell using Aerosol OT (AOT) in hexane solution. The aim of this paper is to determine the quantity of AOT that optimizes microcapsule distribution, diameter, and shell thickness. Different quantitie...

This study investigated the potential utilization of the TBM muck obtained from the Gold Line of the Doha Metro Project as a partial replacement of coarse aggregates in concrete mixes. First, the TBM muck particles were screened to coarse aggregate standard sizes. Then, concrete mixes were prepared using 0%, 25%, 50%, and 75% TBM muck replacement o...

This paper investigates the potential utilization of the Tunnel Boring Machine (TBM) muck generated from Doha’s Metro Gold Line in different construction applications. The properties of the raw TBM muck were studied, and the results were compared to the specifications of Qatari Construction Standards (QCS 2014) of concrete aggregates, fill material...

This paper presents a mathematical model for the analysis of reinforced concrete (RC) uniaxial and biaxial columns. This proposed model is a quick and faster approach for the analysis and design of reinforced concrete rectangular columns without going through the interaction charts procedure as well as other iterative methods for the computation of...

This article presents a simplified analytical model for designing irregular shaped reinforced concrete (RC) footings supporting square column and subjected to eccentric loading, that is, axial load P and biaxial moments, Mx in (x-x) axis and My in (y-y) axis, respectively. In this study, four design variations of footing sections are considered, na...

This paper presents a novel analytical method to generate interaction diagrams useful for the design of reinforced concrete (RC) biaxial columns. Due to the introduction of new classes in concrete compressive strength (fc') with somewhat different parameters for the steel grades (fy), it has become necessary to develop new interaction diagrams. The...

Recently, remarkable types of carbon nanofilaments called carbon nanotubes (CNTs) have raised the interest of many concrete and cementitious composite researchers due to their significant mechanical, electrical, thermal, kinetic, and chemical properties. These nanofilaments are considered promising applicants to use in producing high-performance ce...

This paper presents simple method to estimate the strength design of reinforced concrete beam sections based on structural safety and reliability. Irregular beam shaped sections are commonly used nowadays in the construction industry. This study reveals the simplified method to analyze and design the different irregular shaped beam sections. In thi...

This paper presents analytical method for generating the interaction diagrams for design of reinforced concrete (RC) columns. Due to the introduction of new classes in concrete compressive strength (𝒇𝒄′ )with somewhat different parameters for the steel grades (𝑓𝑦), it has become necessary to develop new interaction diagrams. These proposed interact...

Equivalent square method is a simplified method to overcome the difficulty of analyzing irregular column sections, which has been a constant concern for a structural engineer, to design a safe and economical structure in modern buildings and bridge piers. Irregular column section with its equivalent square column section were both analyzed by finit...

This paper presents a simplified method for the calculation of thin-plate deflections for the regular and irregular plates. The method, which deals with the uniform and concentrated loaded plates, uses the stiffness method to obtain plate deflection equations for specified boundary conditions. A case study was presented to demonstrate the use of th...

Mathcad is a sophisticated computation and presentation tool, which is versatile, easy to use, and accessible. It holds strong potential as a learning aid for education and training. This paper demonstrates the use of Mathcad to supplement and enhance traditional teaching and learning methods both inside and outside the classroom. The paper focuses...

The response of a structural frame to earthquake ground motion is predicted using the structural mixture theory (SMT). This research presents four different case studies to evaluate the performance of the structure mixture theory in the earthquake response analysis of buildings. In the first case study, the actual earthquake responses of the two-st...

This study investigates the compressive and flexural strengths, flexural modulus and air permeability of concrete samples containing 0·75% by cement weight of modified calcium nitrate self-healing microcapsules. The compressive and flexural strengths of concrete mixes with microcapsules were determined before healing and compared with those of the...

This paper investigated the splitting tensile and shear strengths and the modulus of rupture of Self Compacting Concrete (SCC) elements with fly ash, micro silica and polycarboxylate ether superplasticizer for various grades and water-to-binder ratios. The immediate and long term deflections of SCC beams were also studied. Finally, the experimental...

This study investigates the strength reduction associated with incorporating calcium nitrate microcap-sules in concrete. It also proposes modifications to the calcium nitrate micro encapsulation procedure to minimize the concrete strength reduction. These modifications consist of altering the continuous phase composition and keeping that of the aqu...

Self-healing concrete with microencapsulated calcium nitrate was investigated. The compressive strength of concrete admixed with microcapsules (as a percentage of the weight of the cement) was tested and compared with that of control specimens of the same mix design without microcapsules. Surface resistivity tests were conducted to quantify the sur...

The use of encapsulating healing agents that allow the self-healing of concrete has emerged as a potential solution to the current decay and costly maintenance of concrete infrastructure; however, many healing agents are expensive. The objectives of this study were to develop a procedure for the production of urea–formaldehyde microcapsules of calc...

The paper studied the behavior of reinforced concrete triangular and T-beams. Three reinforced concrete beams were tested experimentally and analyzed analytically using the finite element method. Their reliability was also assessed using the reliability index approach. The results showed that the finite element vertical displacements compared well...

The objective of this study is to evaluate a new generation of self-healing materials that hold promise for better durability and performance. The in situ polymerization method was used to develop double-walled microcapsules. The microcapsules were prepared in a single batch process containing sodium silicate as the healing agent encapsulated in do...

Self-compacting concrete (SCC) is a special type of concrete that does not require compaction and vibration for placement. This paper studies the structural behavior of elements made of SCC and compare it to that of elements casted using normally vibrated concrete (NVC). In particular, this research could be considered as a "pilot study" for develo...

The paper develops a reliability index approach to assess the reliability of tall buildings subjected to earthquake loading. The reliability index β model measures the level of reliability of tall buildings in earthquake zones based on their response to earthquake loading and according to their design code. The reliability index model is flexible a...

This paper presents a Drift Design Structural Model (DDSM) for the design optimization of high-rise buildings in seismic zones. The model is formulated as a Generalized Single Degree of Freedom System subjected to equivalent static seismic loadings. The model objectives are: (a) the minimization of the structure weight; (b) the minimization of the...

This paper presents a genetic algorithm model for the cost optimization of composite beams based on the load and resistance factor design (LRFD) specifications of the AISC. The model formulation includes the cost of concrete, steel beam, and shear studs. Two design examples taken from the literature were analyzed in order to validate the proposed m...

This paper presents two case studies to evaluate the performance of the structure mixture theory in the earthquake response analysis of buildings. In the first case study, the actual earthquake responses of the two-story reinforced concrete building, which was tested at the University of California at Berkeley, were compared to those obtained using...

Owing to their nature, numerous and complex equations are commonly used in the design of reinforced concrete structures. This is because of the nature of reinforced concrete design. Mathcad, which possesses efficient computation and presentation capabilities, holds strong potential as a teaching tool and learning aid for education and training. Thi...

This paper presents a design optimization method for all-wood concrete wall forms. This procedure was formulated to provide for a safe wall form design with minimum cost. The proposed method considers in its design process the cost of each wall form components (sheathing, stud, wale, and steel ties) as well as all available combinations of wall for...

A structural mixture theory is developed for use in predicting the response of a structural frame to earthquake ground motion. The frame is considered to be a mixture of columns and beams and is modeled as two interacting subsystems. The dynamic response of each subsystem is described by its own linear differential operator. The two responses are t...

This paper presents a design optimization method for concrete slab forms. This procedure was formulated to provide a safe slab form design with minimum cost. The proposed method considers in its design process the cost of each slab form component (sheathing, joist, stringer, and steel shore) as well as all available combinations of slab form compon...

A simplified method for the design of paraboloid shell footing base on the displacement of the shell's crown where the column axial load is transferred to the footing has been developed. A case study was presented to demonstrate the use of the proposed method and to illustrate its capabilities. The results of the proposed method confirm the ability...

This paper presents two case studies to evaluate the performance of the structure mixture theory in the earthquake response analysis of buildings. In the first case study, the actual earthquake responses of the two-story reinforced concrete building, which was tested at the University of California at Berkeley, were compared to those obtained using...

This paper presents a simplified method for the calculation of thin-plate deflections. The method, which deals with uniformly loaded plates, uses the stiffness method to obtain plate deflection equations for specified boundary conditions. A case study was presented in order to demonstrate the use of the proposed method and to illustrate its capabil...