Mohd Firdaus Omar
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Preferred name
Mohd Firdaus Omar
Official Name
Mohd Firdaus, Omar
Alternative Name
Omar, Mohd Firdaus
Mohd, Firdaus Omar
Omar, M. F.
Omar, Mohdfirdaus
Omar, Mohd F.
Main Affiliation
Scopus Author ID
36149536300
Researcher ID
U-8459-2019

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Partially Replacement of Cement by Sawdust and Fly Ash in Lightweight Foam Concrete

2020-03-18 , Mohd Firdaus Omar , Muhd Afiq Hizami Abdullah , Rashid N.A. , Abdul Latif Abdul Rani

The rapid growth of population has led to increased demand for fast, affordable and quality housing development. Today, the construction industry in Malaysia has shifted from conventional methods to Industrial Building Systems (IBS). The most commonly used IBS component is precasat concrete with lightweight foam concrete. This study focuses on the main component of foam lighweight concrete, which is a partially replacement of cement by sawdust and fly ash. Among the features of lightweight concrete is density below 1800 kg/m3. Therefore, the objectives of this study is to determine the effects of sawdust and fly ash as part of cement replacement in terms of mechanical properties (compressive strenght) and physical properties (water absorption). In addition, this study also determine the optimum percentage of cement replacement by sawdust and fly ash in building material. The percentage of saw dust and fly ash used in this study as a partial replacement cement are 5%, 10%, 15% and 20%. The results show that increasing the percentage of mix propotion will increase the water absorption rate as well as decrease the compressive strenght of strength. Also, the density and compressive strength of lightweight foam concrete will decrease as the percentage of partial replacement cement increases. According to JKR Standard Specification for Building Works that referred in Malaysia, the minimum compression strength of lightweight foam concrete allowed for hollow blocks is 2.8 N/mm2. The results obtained from this study show lightweight concrete blocks using saw dust and fly ash as part of the cement replacement meet the standards and can be commercialized in the industrial building system development.

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Mechanical and dielectric properties of hybrid carbon nanotubes-woven glass fibre reinforced epoxy laminated composites via the electrospray deposition method

2022-01-01 , Muhammad Razlan Zakaria , Nur Aishahatul Syafiqa Khairuddin , Mohd Firdaus Omar , Akil H.M. , Othman M.B.H. , Mohd. Mustafa Al Bakri Abdullah , Shayfull Zamree Abd. Rahim , Sam Sung Ting , Azida Azmi

Herein, the effects of multi-walled carbon nanotubes (CNTs) on the mechanical and dielectric performance of hybrid carbon nanotube-woven glass fiber (GF) reinforced epoxy laminated composited are investigated. CNTs are deposited on woven GF surface using an electrospray deposition method which is rarely reported in the past. The woven GF deposited with CNT and without deposited with CNT are used to produce epoxy laminated composites using a vacuum assisted resin transfer moulding. The tensile, flexural, dielectric constant and dielectric loss properties of the epoxy laminated composites were then characterized. The results confirm that the mechanical and dielectric properties of the woven glass fiber reinforced epoxy laminated composited increases with the addition of CNTs. Field emission scanning electron microscope is used to examine the post damage analysis for all tested specimens. Based on this finding, it can be prominently identified some new and significant information of interest to researchers and industrialists working on GF based products.

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Enhancement of tensile properties of glass fibre epoxy laminated composites reinforced with carbon nanotubes interlayer using electrospray deposition

2022-01-01 , Muhammad Razlan Zakaria , Mohd Firdaus Omar , Hazizan Md Akil , Muhammad Bisyrul Hafi Othman , Mohd. Mustafa Al Bakri Abdullah

The introduction of carbon nanotubes (CNTs) onto glass fibre (GF) to create a hierarchical structure of epoxy laminated composites has attracted considerable interest due to their merits in improving performance and multifunctionality. Field emission scanning electron microscopy (FESEM) was used to analyze the woven hybrid GF-CNT. The results demonstrated that CNT was successfully deposited on the woven GF surface. Woven hybrid GF-CNT epoxy laminated composites were then prepared and compared with woven GF epoxy laminated composites in terms of their tensile properties. The results indicated that the tensile strength and tensile modulus of the woven hybrid GF-CNT epoxy laminated composites were improved by up to 9% and 8%, respectively compared to the woven hybrid GF epoxy laminated composites.

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New High Strength Water Retaining Interlocking Pavers Block for High Mechanical Performing Pavement and Reducing Runoff

2020-03-18 , Muhd Afiq Hizami Abdullah , Rashid N.A. , Abdul Latif Abdul Rani , Mohd Firdaus Omar

Interlocking paver blocks are used widely at low speed traffics road especially surrounding building complexes. Interlocking paver blocks are easy to install and provide aesthetic finishing to the landscape. However, usage of interlocking blocks in large areas reduce ground permeability that lead to higher runoff. New interlocking paver blocks were investigated to reduce runoff and the effect on its mechanical performance. Two types of paver block produced which is paver block with permeable concrete and paver block with void in the center. The results show that the compressive strength for paver block with permeable concrete is averagely higher than paver block with void by 31.5% while the flexural strength of all samples were between 1.0 to 1.7 MPa. Paver block with void recorded highest reduction of runoff compared to paver block with permeable concrete which is 25.5%. This is in line with water infiltration test result. It was concluded that the water retaining performance of paver block increase with increment of void volume and increase in void volume caused reduction on compressive strength of interlocking blocks.

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Potential of soil stabilization using Ground Granulated Blast Furnace Slag (GGBFS) and Fly Ash via Geopolymerization method: A Review

2022-01-01 , Syafiadi Rizki Abdila , Mohd. Mustafa Al Bakri Abdullah , Romisuhani Ahmad , Nergis D.D.B. , Shayfull Zamree Abd. Rahim , Mohd Firdaus Omar , Sandu A.V. , Vizureanu P. , Syafwandi

Geopolymers, or also known as alkali-activated binders, have recently emerged as a viable alternative to conventional binders (cement) for soil stabilization. Geopolymers employ alkaline activation of industrial waste to create cementitious products inside treated soils, increasing the clayey soils’ mechanical and physical qualities. This paper aims to review the utilization of fly ash and ground granulated blast furnace slag (GGBFS)-based geopolymers for soil stabilization by enhancing strength. Previous research only used one type of precursor: fly ash or GGBFS, but the strength value obtained did not meet the ASTM D 4609 (<0.8 Mpa) standard required for soil-stabilizing criteria of road construction applications. This current research focused on the combination of two types of precursors, which are fly ash and GGBFS. The findings of an unconfined compressive strength (UCS) test on stabilized soil samples were discussed. Finally, the paper concludes that GGBFS and fly-ash-based geo-polymers for soil stabilization techniques can be successfully used as a binder for soil stabilization. However, additional research is required to meet the requirement of ASTM D 4609 standard in road construction applications, particularly in subgrade layers.

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The Application of Coconut Fiber as Insulation Ceiling Board in Building Construction

2020-07-09 , Mohd Firdaus Omar , Muhd Afiq Hizami Abdullah , Rashid N.A. , Abdul Latif Abdul Rani , Illias N.A.

This study considers the applications of natural fiber composites in affordable housing projects located in Malaysia with the goal of addressing issues of the thermal comfort. Roof thermal insulation is one of the effective methods that can save cooling energy in places with an equatorial climate especially in Malaysia. The use of recycled products or industrial waste materials is now a potential trend in the industry. Therefore, natural fiber was chosen as a material for the ceiling board in this study. During the day, heat can enter the room from the roof so that insulation material is needed to reduce heat flux by maintaining the temperature of the building. The problems faced by consumers are cost increases due to the use of large amounts of electricity. Besides, asbestos use becoming less frequent because the government has banned its use as a ceiling, side panels, roofing material, asbestos cement-pipes, many types of fireproof and insulation material. The objectives of this study was to determine the mechanical and physical properties of coconut fiber with fire retardant paint as a thermal comfort for ceiling board. The next objective is to study the percentage difference in sodium hydroxide and sodium chloride during the treatment of coconut fiber. The data result is that the fiber is ideal as an insulating material for the house ceiling board because it has a low temperature quality of 0.225W. The water absorption value was as high as 11.20% which is slightly lower than previous studies. Finally, the density test has a value of 74.23 kg / m3 where the fibers are lighter than the other fibers even after immersion with different sodium hydroxide and sodium chloride. In addition, this study achieved a house ceiling that could help reduce the heat entering the house by 0.225W which used only a thickness of 10mm. The use of these fibers does not need the thickness between 20 mm or 40 mm. Therefore, it successfully lowered home electricity consumption in hot weather. It was found that the difference in temperature drop between 0 % and 3 % was 0.4W.

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