Al Merghab University

Al Khums, Libya

Al Merghab University

Al Khums, Libya
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Benisa M.,Al Merghab University | Babic B.R.,University of Belgrade | Grbovic A.,University of Belgrade | Stefanovic Z.,University of Belgrade
FME Transactions | Year: 2014

To produce a new component there are a trial and error stage to obtain a part without defects, which strongly depends on operator's experience. At this stage, the experience of designer and manufacturers should give an important aid to reduce trials to realize the minimization of response time and cost with maximization of the product equality. Rubber pad forming highly improves the formability of the blank because the contact surfaces between the rigid die and the rubber pad is flexible. This method enables to produce sheet metal components with complex contour by relatively low cost because only one rigid die is required. However, in aerospace field, parts are produced in small sheet metal bending and small number of components. It means that it is not worthy for large investments in tools and process design. For these reasons, it is necessary to use FE simulation of manufacturing process during the conceptual design. © Faculty of Mechanical Engineering, Belgrade.


Johari M.A.M.,Universiti Sains Malaysia | Altwair N.M.,Universiti Sains Malaysia | Altwair N.M.,Al Merghab University | Hashim S.F.S.,Universiti Sains Malaysia
Advances in Cement Research | Year: 2013

The fracture and tensile characteristics of engineered cementitious composites (ECCs) containing palm oil fuel ash (POFA) have been investigated. POFA obtained from a palm oil mill was treated first by grinding and then by heat treatment. The treated POFA was then utilised to produce ECCs in combination with polyvinyl alcohol fibres with proportions of POFA ranging from 0 to 1.2 from the mass of cement. The performance of the POFA-ECCs was evaluated by means of matrix fracture and direct tensile tests. The experimental results indicate that the ECC mix containing POFA exhibits lower fracture toughness and fracture energy values than a mix without POFA. Nonetheless, the addition of POFA contributes to a greater pseudo-strain hardening index, in particular at higher POFA content. This reveals that the use of POFA should be helpful for achieving strain hardening behaviour. In addition, an increase in POFA content increases the tensile strain capacity of the ECC. Furthermore, the crack width of the ECC decreases significantly with an increase of POFA content. Thus, the overall findings exhibit that the POFA used brings about promising positive effects on the fracture and tensile characteristics of ECCs.


Altwair N.M.,Universiti Sains Malaysia | Altwair N.M.,Al Merghab University | Megat Johari M.A.,Universiti Sains Malaysia | Saiyid Hashim S.F.,Universiti Sains Malaysia
Construction and Building Materials | Year: 2012

The flexural performance of green engineered cementitious composites (ECCs) containing high volume of palm oil fuel ash (POFA) has been investigated. Three sets of ECC mixtures with water-binder ratios of 0.33, 0.36, and 0.38 were prepared, and for each set, the ECC mixtures were proportioned to have varying POFA contents of 0, 0.4, 0.8, and 1.2 from the mass of cement. The flexural performance was assessed after 3, 28, and 90 days of curing using the four-point bending test. The results suggest that there is a corresponding reduction in the first cracking strength and flexural strength of the ECC beams with the increase of water-binder ratios and POFA content. Nonetheless, higher water-binder ratio and higher POFA content was found to concomitantly improve the flexural deflection capacity, which indicates a superior deflection hardening behaviour. Furthermore, number of cracks was increased and crack width of the ECC was significantly reduced with an increase of POFA content. In addition, there are good correlations between flexural deflection capacity from the four-point bending test and tensile strain capacity from the uniaxial tensile test. © 2012 Elsevier Ltd. All rights reserved.


Altwair N.M.,Universiti Sains Malaysia | Altwair N.M.,Al Merghab University | Megat Johari M.A.,Universiti Sains Malaysia | Saiyid Hashim S.F.,Universiti Sains Malaysia | And 2 more authors.
Advanced Materials Research | Year: 2013

Palm oil fuel ash (POFA) was used to produce engineered cementitious composite (ECC) in this research where ECC mixtures containing different volume of POFA (up to 55% by weight) of cement, were prepared. Mechanical properties of the resulting ECC mixtures were assessed using the compression, flexural and uniaxial tensile tests. The findings of the study show that the use of POFA improves the mechanical properties of the ECCs. The ECC mix with 1.2 POFA/cement ratio achieved a compressive strength of 30 MPa at 28 days, which is within the normal range of concrete strength for many applications. Moreover, the results portray that the use of POFA should be helpful for achieving strain-hardening behaviour. The increase in the POFA content concomitantly increased the flexural deflection and tensile strain capacities of the POFA-ECC. Furthermore, crack width of the ECC was significantly decreased with an increase of POFA content. In addition, the resulting POFA-ECC is expected to enhance the material greenness and durability. © (2013) Trans Tech Publications, Switzerland.


Zeyad A.M.,Universiti Sains Malaysia | Zeyad A.M.,Yemen University of Science and Technology | MEGAT JOHARI M.A.,Universiti Sains Malaysia | MUHAMAD BUNNORI N.,Universiti Sains Malaysia | And 3 more authors.
Advanced Materials Research | Year: 2013

Palm oil fuel ash obtained from palm oil mill was treated via screening, grinding and heating to improve its pozzolanic reactivity. The characteristics of the palm oil fuel ash before and after treatment were monitored to assess the changes in the properties of the palm oil fuel ash. The resulting ultrafine palm oil fuel ash was then utilized to produce high strength concrete by replacing the ordinary Portland cement at 0, 20, 40 and 60% on mass-for-mass basis. The results show that the treatment process undertaken reduces the particle size, diminishes the unburned carbon content, while at the same time increases the glassy phases. The utilization of the ultrafine palm oil fuel ash in high strength concrete was observed to improve workability especially at higher ultrafine palm oil fuel ash content. In addition, the long-term compressive strength of the high strength concrete was significantly increased with the ultrafine palm oil fuel ash inclusion. Further, the long-term rapid chloride permeability was significant reduced especially at higher ultrafine palm oil fuel ash content of 60%, which could be translated into superior durability performance. © (2013) Trans Tech Publications, Switzerland.


Altwair N.M.,Universiti Sains Malaysia | Altwair N.M.,Al Merghab University | Johari M.A.M.,Universiti Sains Malaysia | Hashim S.F.S.,Universiti Sains Malaysia
Advanced Materials Research | Year: 2013

The present paper is a part of an extensive study on green palm oil fuel ash engineered cementitious composites conducted at Universiti Sains Malaysia. It specifically investigates the effects of water-binder ratio (w/b) and palm oil fuel ash (POFA) on the drying shrinkage of engineered cementitious composites (ECCs). W/b values of 0.33, 0.36, and 0.38 were selected. ECC mixes were proportioned to have various ratios of POFA ranging from 0 to 1.2 from the mass of cement. The drying shrinkage measurements were taken at 4, 11, 18, 25, 57, and 90 days. The experimental results show that w/b has a significant effect on the drying shrinkage of the ECC mixtures. Drying shrinkage is remarkably reduced with a decrease in the w/b. The results also showed that drying shrinkage of the composites is considerably reduced when POFA is used in the matrix. The measured drying shrinkage strain at 90 days is only 920×10-6 με to 1216×10-6 με for ECC mixtures with high POFA content. The shrinkage strain of the ECC mixtures without POFA at 90 days is nearly 1597×10-6 με to 1910×10-6 με. © (2013) Trans Tech Publications, Switzerland.


Mijarsh M.J.A.,Universiti Sains Malaysia | Mijarsh M.J.A.,Al Merghab University | Megat Johari M.A.,Universiti Sains Malaysia | Ahmad Z.A.,Universiti Sains Malaysia
Construction and Building Materials | Year: 2015

The aim of this study was to investigate the main factors affecting the compressive strength (σf) development of geopolymer mortar synthesized from treated palm oil fuel ash (TPOFA), with curing period of up to 120 days. The geopolymer mortar was prepared using mixtures of solid material and an alkaline activator. The solid materials used were TPOFA (source material) and mineral additives (Ca(OH)2, Al(OH)3, and silica fume). The alkaline activator was prepared from NaOH and Na2SiO3. The two main factors considered are delay time (i.e., 1 and 24 h) and variation of Na2SiO3 concentrations (i.e., high, medium, and low). The changes in the σf development were examined using X-ray diffraction, and confirmed by FTIR analyses. The results for σf were in agreement with the phase changes and quantitative X-ray diffraction (QXRD) analysis, and also matched the FTIR analysis. It was found that mixtures with 24 h delay time and having high Na2SiO3 concentration produced the highest development of σf at 120 days (78.0% with respect to 28 days). It was evident that the concomitantly developed C-S-H and N-A-S-H binding gels observed at 28 days transformed to a more stable C-A-S-H type gel at prolonged curing period. © 2015 Elsevier Ltd.


Mijarsh M.J.A.,Universiti Sains Malaysia | Mijarsh M.J.A.,Al Merghab University | Megat Johari M.A.,Universiti Sains Malaysia | Ahmad Z.A.,Universiti Sains Malaysia
Construction and Building Materials | Year: 2014

The aim of this study was to synthesize geopolymers using a large amount of treated palm oil fuel ash (TPOFA). The efficiency of the TPOFA (as the source material) in producing geopolymer products was enhanced via six factors which were optimized using the Taguchi method L25. The six factors were divided into two different components: (i) additive materials i.e. Ca(OH)2, silica fume (SF), Al2(OH)3, and (ii) alkaline activators; i.e. NaOH concentration (moles), Na-silicate: NaOH ratio, and alkali-activator:solid- material ratio. Each of these factors was examined on five levels in order to obtain the optimum mixture. A total of 25 mixtures were prepared in accordance to the L25 array proposed by the method. The performance of the specimens was evaluated by compressive strength tests. The results show that the optimum mixture consisted of 65 wt.% TPOFA and 35 wt.% additive materials which achieved a compressive strength of 47.27 ± 5.0 MPa after 7 days of curing. The properties of the optimized mixture were further analyzed via X-ray diffractography (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses. The results show that the main binding phases consist of aluminosilicate type gel "N-A-S-H" (Na2O-Al 2O3-SiO2-H2O) and calcium silicate hydrate (C-S-H) gels, formed simultaneously, within the TPOFA-based geopolymer mortar.©2013 Elsevier Ltd. All rights reserved.


Altwair N.M.,Universiti Sains Malaysia | Altwair N.M.,Al Merghab University | Megat Johari M.A.,Universiti Sains Malaysia | Zeyad A.M.,Universiti Sains Malaysia | And 2 more authors.
Advances in Civil Engineering and Building Materials - Selected Peer Reviewed Papers from 2012 2nd International Conference on Civil Engineering and Building Materials, CEBM 2012 | Year: 2012

This work presents the results of the processing of palm oil waste ash (POWA) under controlled burning conditions in order to obtain materials with good pozzolanic properties. Palm oil waste samples were burnt in an aired electric furnace at 800°C and 1000°C for 6 and 2 h, respectively. Furthermore, treatment of palm oil fuel ash is also discussed. Ground palm oil fuel ash (GPOFA) was treated by heating at 450°C for 90 min. Both of the ashes were characterized by means of chemical analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM) and strength activity index (SAI). Results obtained confirm that POWA burned at 800°C and 1000°C have properties indicative of very high pozzolanic activity. Moreover, no influence of heat treatment was observed on the pozzolanic properties of the treated POFA. © 2013 Taylor & Francis Group, London.

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