Mohd Firdaus Omar
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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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  • Publication
    Effect of Glass Reinforced Epoxy (GRE) pipe filled with geopolymer materials for piping application: compression properties
    ( 2016)
    Mohammad Firdaus Abu Hashim
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Che Mohd Ruzaidi Ghazali
    ;
    Kamarudin Hussin
    ;
    Mohammed Binhussain
    ;
    Mohd Firdaus Omar
    The aim of this paper is to achieve the highest compressive strength of glass reinforced epoxy pipe with the geopolymer filler content of weight percentage that were used in glass reinforced epoxy pipe. The samples were prepared by using the filament winding method. The effect of weight percentage of geopolymer materials in epoxy hardener was studied under mechanical testing, which is using the compression test. A series of glass reinforced epoxy pipe and glass reinforced epoxy pipe filled with 10 – 40 weight percentage geopolymer filler which is white clay were prepared. The compression strength of the glass reinforced epoxy pipe filled geopolymer materials is determined using Instron Universal Testing under compression mode. It was found that compressive strength for samples with white clay geopolymer filler are much higher compare to glass reinforced epoxy pipe without geopolymer filler. Moreover, the compressive strength of glass reinforced epoxy pipe filled with white clay geopolymer filler was increased from 10 wt% to 30 wt% of geopolymer content. However, the compressive strength of glass reinforced epoxy pipe with white clay geopolymer filler suddenly decreased when added to 40 wt%. The results indicated that the blending of geopolymer materials in epoxy system can be obtained in this study.
  • Publication
    Potential of soil stabilization using Ground Granulated Blast Furnace Slag (GGBFS) and fly ash via geopolymerization method: a review
    ( 2022)
    Syafiadi Rizki Abdila
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Romisuhani Ahmad
    ;
    Dumitru Doru Burduhos Nergis
    ;
    Shayfull Zamree Abd. Rahim
    ;
    Mohd Firdaus Omar
    ;
    Andrei Victor Sandu
    ;
    Petrica Vizureanu
    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.
  • Publication
    Mechanical and dielectric properties of hybrid carbon nanotubes-woven glass fibre reinforced epoxy laminated composites via the electrospray deposition method
    ( 2021)
    Muhammad Razlan Zakaria
    ;
    Nur Aishahatul Syafiqa Mohammad Khairuddin
    ;
    Mohd Firdaus Omar
    ;
    Hazizan Md Akil
    ;
    Muhammad Bisyrul Hafi Othman
    ;
    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
  • Publication
    Enhancement of tensile properties of glass fibre epoxy laminated composites reinforced with carbon nanotubes interlayer using electrospray deposition
    ( 2021)
    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.
  • Publication
    Improving flexural and dielectric properties of carbon fiber epoxy composite laminates reinforced with carbon nanotubes interlayer using electrospray deposition
    ( 2020)
    Muhammad Razlan Zakaria
    ;
    Hazizan Md Akil
    ;
    Mohd Firdaus Omar
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Aslina Anjang Ab Rahman
    ;
    Muhammad Bisyrul Hafi Othman
    The electrospray deposition method was used to deposit carbon nanotubes (CNT) onto the surfaces of woven carbon fiber (CF) to produce woven hybrid carbon fiber–carbon nanotubes (CF–CNT). Extreme high-resolution field emission scanning electron microscopy (XHR-FESEM), X-ray diffraction (XRD), Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR) were used to analyze the woven hybrid CF–CNT. The results demonstrated that CNT was successfully and homogenously distributed on the woven CF surface. Woven hybrid CF–CNT epoxy composite laminates were then prepared and compared with woven CF epoxy composite laminates in terms of their flexural and dielectric properties. The results indicated that the flexural strength, flexural modulus and dielectric constant of the woven hybrid CF–CNT epoxy composite laminates were improved up to 19, 27 and 25%, respectively, compared with the woven CF epoxy composite laminates.
  • Publication
    Nonisothermal kinetic degradation of Hybrid CNT/Alumina Epoxy Nanocomposites
    ( 2021)
    Muhammad Helmi Abdul Kudus
    ;
    Muhammad Razlan Zakaria
    ;
    Mohd Firdaus Omar
    ;
    Muhammad Bisyrul Hafi Othman
    ;
    Hazizan Md. Akil
    ;
    Marcin Nabiałek
    ;
    Bartłomiej Jeż
    ;
    Mohd. Mustafa Al Bakri Abdullah
    Due to the synergistic effect that occurs between CNTs and alumina, CNT/alumina hybrid-filled epoxy nanocomposites show significant enhancements in tensile properties, flexural properties, and thermal conductivity. This study is an extension of previously reported investigations into CNT/alumina epoxy nanocomposites. A series of epoxy composites with different CNT/alumina loadings were investigated with regard to their thermal-degradation kinetics and lifetime prediction. The thermal-degradation parameters were acquired via thermogravimetric analysis (TGA) in a nitrogen atmosphere. The degradation activation energy was determined using the Flynn–Wall–Ozawa (F-W-O) method for the chosen apparent activation energy. The Ea showed significant differences at α > 0.6, which indicate the role played by the CNT/alumina hybrid filler loading in the degradation behavior. From the calculations, the lifetime prediction at 5% mass loss decreased with an increase in the temperature service of nitrogen. The increase in the CNT/alumina hybrid loading revealed its contribution towards thermal degradation and stability. On average, a higher Ea was attributed to greater loadings of the CNT/alumina hybrid in the composites.
  • Publication
    Evaluation on physical and chemical properties of treated industrial wastewater sludge containing latex and heavy metals using ordinary Portland cement via stabilization / solidification technique
    ( 2020-07-09)
    Abdul Latif Abdul Rani
    ;
    Rashid N.A.
    ;
    Muhd Afiq Hizami Abdullah
    ;
    Mohd Firdaus Omar
    Industrial wastewater sludge containing latex collected from rubber industry wastewater treatment plant has classified the waste as scheduled waste due to high concentration of selected heavy metals within it. Laboratory scale of special treatment via solidification/stabilization (S/S) technique has been performed to the waste by using ordinary Portland cement. The objective of this research is to evaluate the chemical properties of the raw waste using X-Ray Fluorescence (XRF) and physical properties related to unconfined compressive strength (UCS) performance of stabilised/solidified (s/s) cube specimens. Other factors took into consideration include the curing condition using air and water immersion curing technique, waste addition percentage, specimen age and density. The fresh mix prepared were cast in plastic moulds internal dimension of 50 mm3 producing cubical shape specimens and cured approximately 24 to 48 hours. The prepared specimen batches are A1 (90% OPC + 10% waste), A2 (70% OPC + 30% waste), A3 (50% OPC + 50% waste). Chemical analyses using XRF indicates that raw sludge contains approximately several heavy metals such as Aluminium (30%), Phosphorus, P (17.5%) and Zinc, Zn (11.7%). UCS testing were conducted on 7 and 28 days of specimen age. Positive average compressive strength results of 7 day air cured specimens reach 5.25 MPa, 5.28 MPa, and 2.16 MPa for A1, A2 and A3. Next, 28 days air cured specimens results are 9.59 MPa, 8.01 MPa, and 1.46 MPa for A1, A2, and A3 respectively. As for water immersion, the compressive strengths are 8.19 MPa, 4.93 MPa, and 1.90 MPa for 7 days, and 7.75 MPa, 10.10 MPa, and 2.11 MPa for 28 days at respective A1, A2 and A3 sequence. Based on the UCS performance, the tested specimens surpassed the minimum requirement for secured landfill disposal which is at 1 MPa.
  • Publication
    Effect of Using Soap Nut as Natural Foaming Agent on Mechanical Properties and Pore Distribution of High Strength Aerated Concrete
    ( 2020-07-09)
    Muhd Afiq Hizami Abdullah
    ;
    Rashid N.A.
    ;
    Abdul Rani A.L.
    ;
    Mohd Firdaus Omar
    ;
    Tan Chan Sin
    Aerated concrete is a type of concrete that contains pore in its matrix structure. This pores could provide spaces for water absorption which makes aerated concrete more durable toward freeze-thaw cycle. Many methods have been studied in forming an aerated concrete and using soap nut as aerating agent is more sustainable than other chemically formulated agent. Forming of pore inside concrete not only improve freeze-thaw cycle durability but also as places to store healing agent in concrete. This is important in developing a self-healing concrete especially a microbial induced healing. This paper aims to study the effect of using soap nut in high strength concrete. Four types of high strength concrete samples were prepared which are Control sample, AE2 with 2% of aerated soap nut, AE4 with 4% of aerated soap nut and AE6 with 6% of aerated soap nut. Total of 3nos. of 100mm cubes and 3nos. of 50mm cubes from each type of samples were prepared. Cubes samples of 100mm dimension were tested for water absorption and compressive strength while cube samples of 50mm dimension were split and analysed for pore distribution. The results showed that increase in addition of soap nut in concrete mixture resulted in decrease of compressive strength but minimal effect on its water absorption rate. Pore formation and dispersion were optimum in concrete with 4% and 6% inclusion of soap nut. In conclusion, 4% of aerated soap nut in high strength concrete present the optimum characteristic in producing well-dispersed pores of high strength aerated concrete.
  • Publication
    Investigation of Biosand Filter (BSF) on the Treatment Performance of Industrial Latex Wastewater
    ( 2024-01-01)
    Najihah Abdul Rashid
    ;
    Abdul Latif Abdul Rani
    ;
    Mohd Firdaus Omar
    ;
    Zainol N.A.
    ;
    Salwa Mohd Zaini Makhtar
    ;
    A B Wahab M.
    ;
    Nabilah Aminah Lutpi
    ;
    Farrah Aini Dahalan
    Biosand Filters (BSF) has great potential to improve the water quality. BSF is used extensively in the treatment of drinking water in rural areas because it is affordable, simple to use, and has a high removal efficiency. This study used actual latex effluent to examine the effectiveness of SBR. The growth of the biolayer in the BSF is also observed. This study analyzes consistent and stable results for COD, DO and NH4-N+. With removal performance ranging from 87 % to 99 %. DO value for BSF varied from lowest value of 1.5 mg/L to 8mg/L. Overall, the BSF was capable of producing treated water for water reclamation.
  • Publication
    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.