Ahmad B. Malkawi
@bau.edu.jo
Civil Engineering Department/ Faculty of Engineering Technology
Al-Balqa Applied University
Ph.D. in civil engineering, having about 13 years of experience in the field of education and 3 years in construction industries. Consistent and outstanding academic records. Thorough understanding of the underlying principles of the subject and its relevance to others. Highly gifted in research and teaching aptitude. Knowledge of various techniques and approaches applied to research projects. Knowledge about the internal administrative tasks and practices that are performed within educational institutions. Highly innovative in depicting the subject matter to the students/audience, using traditional methods as well as modern aids.
EDUCATION
PhD of Civil Engineering
RESEARCH INTERESTS
Construction materials, Structural engineering, Non-destructive testing and evaluation, Numerical modelling and optimization
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Ali A. Mahameid, Amjad A. Yasin, and Ahmad B. Malkawi
Horizon Research Publishing Co., Ltd.
Amjad A. Yasin, Ahmad B. Malkawi, Muhmmad I. M. Rjoub, Hani Qadan, Faroq Maraqa, and Jamal Aladwan
Horizon Research Publishing Co., Ltd.
Hashem Al-Mattarneh, Musab Abuaddous, Rabah Ismail, Ahmad B. Malkawi, Yaser Jaradat, Hamsa Nimer, and Mohanad Khodier
American Institute of Mathematical Sciences (AIMS)
<p>This study evaluates the utilization of biomass olive oil waste ash (OA) as a concrete paving material. Concrete pavement was produced by replacing a portion of Portland cement with OA at different percentages up to 15%. An additional set of concrete pavement was prepared by incorporating OA with nano-silica (NS) at various contents up to 1.5%. The optimal replacement contents of OA or OA and NS were investigated in terms of workability, compressive strength, strength development rate, and durability. The results showed that the optimal replacement level of OA content was 7.5%. The incorporation of NS with OA increased the optimal replacement level to 15%. The incorporation of NS with OA improved the strength, durability, and workability of all mixes. The utilization of OA with NS at optimal levels can produce concrete pavements. Using NS and OA, approximately 10 % cost savings could be achieved, together with a sustainable, environmentally friendly disposal method of olive oil waste.</p>
Hashem Al–Mattarneh, Ahmad B. Malkawi, Rabah Ismail, Faris Matalkah, Yaser Jaradat, and Issam Trrad
IEEE
Concrete structures exhibit improved damage resistance and performance with the inclusion of steel fibers. The performance of fiber-reinforced concrete (FRC) is significantly influenced by fiber content, distribution, and orientation. However, there is currently no widely accepted technique for efficiently evaluating these factors, especially on-site. This paper explores the viability of employing a surface electromagnetic sensor (rectangular waveguide) as a non-destructive microwave testing apparatus to assess the concentration, dispersion, and orientation of steel fibers in concrete. The testing requires access to only one side of the FRC material and necessitates direct contact with the surface to measure the microwave electromagnetic characteristics at various points. Additionally, the sensor's ability to rotate allows for the assessment of fiber orientation by polarizing the electric field at different angles. The study reveals that the measured reflection properties exhibit a rise in mean value with increasing fiber content and improved fiber distribution. Furthermore, the findings indicate that the microwave reflection characteristics are minimized when the fibers are oriented perpendicular to the electric field and maximized when aligned parallel to it. Regression analysis was conducted to establish the relation between the measured microwave electromagnetic characteristics and fiber content and flexural strength. The proposed models can estimate the fiber content and the flexural strength based on the measured wave reflection with determination coefficients of 0.98 and 0.945, respectively at the 10 GHz frequency range.
Hashem Al-Mattarneh, Adnan Rawashdeh, Rabah Ismail, Faris Matalkah, Nour Alhussien, and Ahmad Malkawi
IEEE
Geopolymer concrete is a complex composite material and its properties such as workability and strength are incredibly unpredictable. A current unresolved issue is the lack of finding a standardized method for predicting the properties of geopolymer binders based on the ratios of mixing. Also, employing traditional testing techniques is expensive and time-consuming. Consequently, the objective herein is to resolve such issue. This paper describes the establishment of user-friendly software system that uses response surface methodology and central composite design to predict the workability and strength of geopolymer concrete. The software has an easy-to-use interface and was created in the MATLAB environment. Data about the mix proportion of geopolymer concrete blend and its properties, like workability and strength, could be imported into the software from an Excel file. The software developed linear and nonlinear empirical regression models to relate the constituents of the geopolymer concrete using response surface methodology. In addition, the system uses residual, mean square error, F-test, significant, and square correlation coefficient as quality fit parameters to identify the optimal model. Furthermore, the system offers the user a module for forecasting the performance of a specified mixed proportion. Thirty-one geopolymer mixes were prepared and used to calibrate the software. Another four mixes were used to validate the computation of the system. The principles of graphical user interface (GUI) design have been applied herein to produce a user-friendly software. These principles include balanced layout, grouping of related data, alignment, justification, highlighting as appropriate, and navigation control.
Rabah Ismail, Hashem Al-Mattarneh, Ahmad B. Malkawi, Musab Abuaddous, Marwa Aljamal, and Issam Trrad
IEEE
Wood is a natural sustainable orthogonal material. It is a renewable construction material but measuring its strength properties is costly, time-consuming, may provide significant variations. Standard methods for measuring wood strength and moisture characteristics are destructive in nature. Therefore, the necessity to establish innovative nondestructive methods for wood application is critical. This paper presents the development and use of Free Space Microwave Transmission Line Nondestructive Testing (FSMTL-NDT) to evaluate moisture and strength properties of wood. The measured complex permittivity of wood using the proposed FSMTL-NDT was related to the moisture and strength properties of wood. Seventeenth Malaysian wood spices were collected and tested to determine its physical, mechanical and dielectric properties. Wood samples also tested at various moisture content and at different rain angles. The results indicate that wood moisture content and compressive strength could be predicted using the permittivity of wood. The results also show that, in the longitudinal direction, the dielectric constant and loss factor are observed to be higher compared to those in the radial and tangential directions. However, there isn't a substantial distinction between the dielectric properties in the radial and tangential directions. It's noted that dielectric constants decrease as the angle between the electric field direction and the timber grain direction increases. Leveraging the measured dielectric constants via microwave methods enables the determination of the angle between the electric field and timber grain direction.
Marsail Al Salaheen, Wesam Salah Alaloul, Khalid Mhmoud Alzubi, Ahmad bahaa Aldin Malkawi, and Muhammad Ali Musarat
Elsevier BV
Amjad A. Yasin, Mohammad T. Awwad, Ahmad B. Malkawi, Faroq R. Maraqa, and Jamal A. Alomari
Ital Publication
Tuff stones are volcanic sedimentary rocks formed by the consolidation of volcanic ash. They possess unique geological properties that make them attractive for a variety of construction and architectural applications. Considerable amounts and various types of Tuff stones exist in the eastern part of Jordan. However, the use of Tuff stones often requires experimental investigations that can significantly impact the accuracy of their physical and mechanical characteristics. To ensure consistent and predictable properties in their mix design, it is essential to minimize the effects of these experimental procedures. Artificial neural networks (ANNs) have emerged as a promising tool to address such challenges, leveraging their ability to analyze complex data and optimize concrete mix design. In this research, ANNs have been used to predict the optimum content of Tuff fine aggregate to produce structural lightweight concrete with a wide range (20 to 50 MPa) of compressive strength. Three different types of Tuff aggregates, namely gray, brown, and yellow Tuff, were experimentally investigated. A set of 68 mixes was produced by varying the fine-tuff aggregate content from 0 to 50%. Concrete cubes were cast and tested for their compressive strength. These samples were then used to form the input dataset and targets for ANN. ANN was created by incorporating the recent advancements in deep learning algorithms, and then it was trained, validated using data collected from the literature, and tested. Both experimental and ANN results showed that the optimum content of the various types of used Tuff fine aggregate ranges between 20 to 25%. The results revealed that there is a clear agreement between the predicted values using ANN and the experimental ones. The use of ANNs may help to cut costs, save time, and expand the applications of Tuff aggregate in lightweight concrete production. Doi: 10.28991/CEJ-2023-09-11-013 Full Text: PDF
Khalid Mhmoud Alzubi, Wesam Salah Alaloul, Ahmad B. Malkawi, Marsail Al Salaheen, Abdul Hannan Qureshi, and Muhammad Ali Musarat
Elsevier BV
Ahmad B. Malkawi
MDPI AG
The influence of geopolymer binder characteristics on the performance of geopolymer concrete has been extensively investigated. Yet, the influence of aggregate properties has not been thoroughly studied, and it is usually assumed that their effect is the same as in cement concrete. This study investigates the effect of aggregate on the performance of fly-ash-based geopolymer concrete. A systematic experimental study was undertaken to investigate the effect of aggregate parameters, including volume fractions (AVFs), coarse aggregate to the total aggregate ratio (CAR), maximum coarse aggregate size (MAS), and fineness modulus of fine aggregate (FFM) on the compressive strength, slump, apparent volume of permeable pores (AVPPs), and the air content of geopolymer concrete. Response surface methodology (RSM) using the central composite design approach was utilized to design the experiments and analyze the results statistically. The analysis shows that all of the investigated aggregate parameters have significant first-order effects on the measured properties. No significant interaction between any of the investigated parameters was found. The aggregate may alter the geopolymerization processes, whereby SEM-EDS analysis revealed statistically significant variations in the elemental concentrations of the produced paste as the aggregate parameters changed. Quantitative weights were assigned to the effect of the investigated aggregate parameters on the measured properties. Multi-objective optimization was carried out to obtain the best combinations of the investigated parameters. Additionally, the developed contour graphs may provide an effective tool that can be used as a guide in establishing the first trial mixtures. A wide range of consistencies (10–210 mm slump) and compressive strengths (15–55 MPa) can be obtained by controlling the aggregate grading and proportions.
Marsail Al Salaheen, Wesam Salah Alaloul, Ahmad B. Malkawi, Jorge de Brito, Khalid Mhmoud Alzubi, Abdulnaser M. Al-Sabaeei, and Mohamad Sahban Alnarabiji
Materials MDPI AG
Fly oil shale ash (FOSA) is a waste material known for its pozzolanic activity. This study intends to investigate the optimum thermal treatment conditions to use FOSA efficiently as a cement replacement material. FOSA samples were burned in an electric oven for 2, 4, and 6 h at temperatures ranging from 550 °C to 1000 °C with 150 °C intervals. A total of 333 specimens out of 37 different mixes were prepared and tested with cement replacement ratios between 10% and 30%. The investigated properties included the mineralogical characteristics, chemical elemental analysis, compressive strength, and strength activity index for mortar samples. The findings show that the content of SiO2 + Al2O3 + Fe2O3 was less than 70% in all samples. The strength activity index of the raw FOSA at 56 days exceeded 75%. Among all specimens, the calcined samples for 2 h demonstrated the highest pozzolanic activity and compressive strength with a 75% strength activity index. The model developed by RSM is suitable for the interpretation of FOSA in the cementitious matrix with high degrees of correlation above 85%. The optimal compressive strength was achieved at a 30% replacement level, a temperature of 700 °C for 2 h, and after 56 days of curing.
Wesam Salah Alaloul, Khalid M. Alzubi, Ahmad B. Malkawi, Marsail Al Salaheen, and Muhammad Ali Musarat
Emerald
PurposeThe unique nature of the construction sector makes it fall behind other sectors in terms of productivity. Monitoring construction productivity is crucial for the construction project's success. Current practices for construction productivity monitoring are time-consuming, manned and error prone. Although previous studies have been implemented toward reducing these limitations, a gap still exists in the automated monitoring of construction productivity.Design/methodology/approachThis study aims to investigate and assess the different techniques used for monitoring productivity in building construction projects. Therefore, a mixed review methodology (bibliometric analysis and systematic review) was adopted. All the related publications were collected from different databases, which were further screened to get the most relevant based on the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) criteria.FindingsA detailed review was performed, and it was found that traditional methods, computer vision-based and photogrammetry are the most adopted data acquisition for productivity monitoring of building projects, respectively. Machine learning algorithms (ANN, SVM) and BIM were integrated with monitoring tools and technologies to enhance the automated monitoring performance in construction productivity. Also, it was observed that current studies did not cover all the complex construction job sites and they were applied based on a small sample of construction workers and machines separately.Originality/valueThis review paper contributes to the literature on construction management by providing insight into different productivity monitoring techniques.
Hani Qadan, Amjad A. Yasin, Ahmad B. Malkawi, and Muhmmad I. M Rjoub
Ital Publication
Failure of flat slabs usually occurs by punching shear mode. Current structural codes provide an experience-based design provision for punching shear strength which is often associated with high bias and variance. This paper investigates the effect of adding a horizontal reinforcement mesh at the top of the slab-column connection zone on punching the shear strength of flat slabs. A new equation considering the effect of adding this mesh was proposed to determine the punching shear strength. The proposed equation is based on the Critical Shear Crack Theory combined with the analysis of results extracted from previous experimental and theoretical studies. Moreover, the equation of load-rotation curves for different steel ratios together with the failure criterion curves were evaluated to get the design points. The investigated parameters were the slab thicknesses and dimensions, concrete strengths, size of the supporting column, and steel ratios. The model was validated using a new set of specimens and the results were also compared with the predictions of different international design codes (ACI318, BS8110, AS3600, and Eurocode 2). Statistical analysis provides that the proposed equation can predict the punching shear strength with a level of high accuracy (Mean Square Error =2.5%, Standard Deviation =0.104, Mean=1.0) and over a wide range of reinforcement ratios and compressive strengths of concrete. Most of the predictions were conservative with an underestimation rate of 12%. Doi: 10.28991/CEJ-2022-08-01-013 Full Text: PDF
Wesam Salah Alaloul, Marsail Al Salaheen, Ahmad B. Malkawi, Khalid Alzubi, Abdulnaser M. Al-Sabaeei, and Muhammad Ali Musarat
Elsevier BV
Ahmed Adel Emhemed Elzokra, Ausamah Al Houri, Ahed Habib, Maan Habib, and Ahmad Malkawi
Ital Publication
Concrete is indeed one of the most consumed construction materials all over the world. In spite of that, its behavior towards absolute volume change is still faced with uncertainties in terms of chemical and physical reactions at different stages of its life span, starting from the early time of hydration process, which depends on various factors including water/cement ratio, concrete proportioning and surrounding environmental conditions. This interest in understanding and defining the different types of shrinkage and the factors impacting each one is driven by the importance of these volumetric variations in determining the concrete permeability, which ultimately controls its durability. Many studies have shown that the total prevention of concrete from undergoing shrinkage is impractical. However, different practices have been used to control various types of shrinkage in concrete and limit its magnitude. This paper provides a detailed review of the major and latest findings regarding concrete shrinkage types, influencing parameters, and their impacts on concrete properties. Also, it discusses the efficiency of the available chemical and mineral admixtures in controlling the shrinkage of concrete.
Ahmad B. Malkawi, Maan Habib, Jamal Aladwan, and Yazan Alzubi
Informa UK Limited
ABSTRACT This paper reports the findings of an experimental programme to investigate the development of a structural lightweight concrete mixture using geopolymer binder and palm oil biowastes. Several concrete mixes were prepared using fly ash-based geopolymer binder, crushed palm oil clinker as asource for lightweight aggregate (POCA), and oil palm trunk fibre (OPTF)as a natural fibre reinforcement. POCA was added at 25%, 50%, 75%, and 100% as volume percentages from total aggregate. OPTF was added at 1%, 2%, and 3% as volume percentages of the mixture. The produced concrete mixtures were evaluated in terms of fresh and harden properties and structural efficiency. The results revealed that OPTF can be used at full replacement level to produce structural lightweight concrete having a compressive strength of more than 30 MPa. In terms of structural efficiency, the optimum POCA content was found at 75% replacement. The optimum OPTF content was found at 1%. Incorporation of POCA and OPTF at any percentage reduced the durability of the concrete produced against acid attack. Yet, the produced mixtures provided good resistance superior to that of conventional concrete. The use of a geopolymer binder boosted the workability, mechanical properties, and durability of the mixtures produced.
Maan Habib, Yazan Alzubi, Ahmad Malkawi, and Mohammad Awwad
Walter de Gruyter GmbH
Abstract There is no doubt that the tremendous development of information technology was one of the driving factors behind the great growth of surveying and geodesy science. This has spawned modern geospatial techniques for data capturing, acquisition, and visualization tools. Digital elevation model (DEM) is the 3D depiction of continuous elevation data over the Earth’s surface that is produced through many procedures such as remote sensing, photogrammetry, and land surveying. DEMs are essential for various surveying and civil engineering applications to generate topographic maps for construction projects at a scale that varies from 1:500 to 1:2,000. GIS offers a powerful tool to create a DEM with high resolution from accurate land survey measurements using interpolation methods. The aim of this research is to investigate the impact of estimation techniques on generating a reliable and accurate DEM suitable for large-scale mapping. As a part of this study, the deterministic interpolation algorithms such as ANUDEM (Topo to Raster), inverse distance weighted (IDW), and triangulated irregular network (TIN) were tested using the ArcGIS desktop for elevation data obtained from real total station readings, with different landforms to show the effect of terrain roughness, data density, and interpolation process on DEM accuracy. Furthermore, comparison and validation of each interpolator were carried out through the cross-validation method and numerous graphical representations of the DEM. Finally, the results of the investigations showed that ANUDEM and TIN models are similar and significantly better than those attained from IDW.
Ahmad B. Malkawi
International Journal of Geomate
The palm oil industry generates a significant amount of wastes which their managing has been a major environmental concern in producing countries. The utilization of these wastes as an aggregate source for concrete production will help to sanitize the environment and provides a cheaper and renewable aggregates source for construction industries. This paper presents the results of the experimental program conducted on fly-ash based geopolymer concrete containing Palm Oil Clinker Aggregate (POCA). Several geopolymer concrete mixes were prepared in which POC was used as a replacement to both fine and coarse aggregates at different percentages starting from 25% to 100%. Mix proportioning was done in accordance with ACI 211.1-91. Geopolymer concrete specimens were cast, cured at ambient conditions and tested for the slump, density, water absorption and compressive, shear and flexural strengths. Overall, the use of fly ashbased geopolymer binder and POCA can enhance the sustainability aspects in concrete production as well as produce a high strength concrete. A concrete mixture containing 100% POCA can produce a structural lightweight concrete having a compressive strength of more than 30 MPa and a density of 1821 kg/m3. The use of a geopolymer binder promotes the workability and strength of POCA concrete and reduces its water absorbability. Incorporation of POCA up to 75% did not much change the structural efficiency of the produced concrete, while it was reduced by 32% when the POCA fully replaced the natural aggregate. Nevertheless, the benefits in terms of cost, energy, and environmental savings cannot be overlooked.
Yazan Alzubi*, , Ahmad B. Malkawi, Maan Habib, , and
Blue Eyes Intelligence Engineering and Sciences Engineering and Sciences Publication - BEIESP
This study aimed to analyzethe mediating impact of competence adequacy on organizational health and technology disruption. Leading construction firms in Jordan participated in this quantitative study and he results revealed significant positive effects of competence adequacy, on organisational health. These findingsprove to be an important contribution and implications to both practitioners and policy makers. Moreover, advantageous insights on how CA, TD can enhance the overall organizational health is also provided by this study. Findings and contributions of the study are as follows. Firstly, Jordanian construction firms will get more insight on the importance of institutionalizing competence building in their establishments by increasing awareness in managers. Additionally, anticipating environmental changes like technology disruption are also highlighted by the findings which guide organisations to achieve a sustainable edge over competitors at the marketplace and for future survival.
Ahmad B. Malkawi, Hashem Al-Mattarneh, Bitrus Emmanuel Achara, Bashar S. Mohammed, and Muhd Fadhil Nuruddin
Elsevier BV
Mohd Fadhil Nuruddin, Amir Fauzi, Mohamed Mubarak Abdul Wahab, Nasir Shafiq, and Ahmad B. Malkawi
Trans Tech Publications, Ltd.
Industrial waste products can be considered as renewable resources. Steel industry wastes have a severe impact on the environment whereas this industry involves a myriad of operations which create vast volumes of air emissions, liquid effluents, and solid wastes. This study presents the feasibility of using Electric Arc Furnace Dust (EAFD) as a cement replacement material (CRM) in comparison with silica fume (SF) and fly ash (FA). The EAFD is a complex byproduct material of steel produced by electrical - arc furnace and consisting mostly of metal oxides. The results showed that the workability of the EAFD mixes is comparable to the control mix even when the percentage of the EAFD was increased. On the other hand, as the replacement percentage was increased, the use of FA, SF resulted in higher, lower workability, respectively. Furthermore, the EAFD significantly affected the setting time, where 3% of the EAFD replacement resulted in prolonging setting time reached more than 24 hours, while the use of SF and FA has insignificantly affected the setting time. The 3% of EAFD is found to be the optimum replacement in terms of compressive strength and it has a similar effect to a replacement level of 5% of SF and 15% of FA.
Ahmad B. Malkawi, Mohd Fadhil Nuruddin, Amir Fauzi, Hashem Al-Mattarneh, and Bashar S. Mohammed
Trans Tech Publications, Ltd.
In this study, different types of plasticizers were used to investigate their effects on the fresh and hardened properties of high calcium fly ash geopolymers (HCFA). Modified polycarboxylate polymers (G3) and lignin-based polymers (G1) were used as plasticizing admixtures and the results were compared to the effect of tap water addition. The results showed that all the admixtures used are effective in increasing the workability of the HCFA geopolymers mixtures and the workability increased by 25-48% compared to the control mixtures. However, the use of G3 has adversely affected the strength by a reduction of 20%. While the use of G1 reduced the final setting time by 7% which is critical in the case of HCFA geopolymers where the final setting time occurs within 70 minutes. Water can be considered as the best admixture in terms of cost, setting time, and effect on compressive strength and it can be used where medium workability enhancement is required.
Amir Fauzi, Mohd Fadhil Nuruddin, Ahmad B. Malkawi, Mohd Mustafa Al Bakri Abdullah, and Bashar S. Mohammed
Trans Tech Publications, Ltd.
Geopolymer system is new binding materials in concrete industry that is produced by the alkaline solution and materials rich in aluminosilicate such as fly ash. The effect of the alkaline solution to fly ash ratios of 0.3, 0.4 and 0.5 on mortar geopolymer properties was an issue in this study. The results showed that the higher alkaline solution to fly ash ratio improves the workability and brings a longer setting time, whereas the lower alkaline solution to fly ash ratio gains the significant compressive strength. It was a similar pattern with conventional mortar used ordinary Portland cement, which the compressive strength at 7 days was 85%-90% for 28 days compressive strength, whereas conventional mortar is only 65%-75%. This was due to the higher reactivity in geopolymer system that was faster than the pozzolanic reaction.
Nabil M. Al-Akhras, M. Jamal Shannag, and Ahmad B. Malkawi
Informa UK Limited
A series of twenty-two shear-deficient lightweight reinforced concrete (LWRC) beams were casted and tested under four-point flexural loading to investigate the structural behaviour of shear-deficient LWRC beams retrofitted with adhesively bonded carbon fibre reinforced polymers (CFRP) sheets. The variables investigated in the study include as follows: shear-span to effective-depth ratio and different retrofitting schemes. The overall response of the LWRC beams, the onset of cracking, crack development and ductility were investigated. The experimental results indicated that the contribution of the CFRP to restore the shear capacity of the shear-deficient LWRC beams was significant. The ultimate shear strength of the retrofitted LWRC beams increased significantly (23–96%) depending on the technique used. The use of the CFRP transformed the mode of failure of some LWRC beams into a more ductile flexural one. The most effective technique for enhancing the shear capacity of the LWRC beams was the CFRP jacketing, followed by the U-strips, inclined strips, and side strips, respectively. The dominant failure mode for the retrofitted LWRC beams was the CFRP debonding from the beams surface by shearing of the concrete skin. An analytical model was developed and showed good correlation with the test results of this investigation.