UniMAP RIS :: Browsing Journal Articles by Issue Date

Publication

Adsorption and toxicity of heavy metals on activated sludge

( 2010)

Ong Soon An

;

Eiichi Toorisaka

;

Makoto Hirata

;

Tadashi Hano

The adsorption of Cu, Cd, Ni, Zn, and Cr from synthetic solutions on powdered activated carbon (PAC), activated sludge, and dried sludge were investigated under laboratory conditions to assess its ability to remove heavy metals. The adsorption efficiency increased rapidly within the first 30 min and then slowed down as it approached a steady state after 5 h of contact time. The results showed that activated sludge and PAC had a higher adsorption capacity than dried sludge. However, PAC showed a better adsorption capacity for Cu, Zn, and Ni than activated sludge. The maximum adsorption capacity, as quantified by the Langmuir parameter Q for activated sludge was 44, 30, 24, 23, and 18 mg/g for Cu, Ni, Cd, Cr, and Zn, respectively. In the case of dried sludge, the respective values of Q were 20, 13, 11, 3, and 10 mg/g. The acute toxicity of these five heavy metals to the activated sludge microorganisms was determined on the basis of the reduction in the specific oxygen uptake rate (SOUR). The results obtained from the SOUR measurements indicated a decreasing toxicity scale, Cu > Cd > Ni ' Cr > Zn on activated sludge microorganisms.

1 12

Publication

Fly ash-based geopolymer lightweight concrete using foaming agent

( 2012)

Mohd. Mustafa Al Bakri Abdullah

;

Kamarudin Hussin

;

Mohamed Bnhussain

;

Khairul Nizar Ismail

;

Zarina Yahya

;

Rafiza Abdul Razak

In this paper, we report the results of our investigation on the possibility of producing foam concrete by using a geopolymer system. Class C fly ash was mixed with an alkaline activator solution (a mixture of sodium silicate and NaOH), and foam was added to the geopolymeric mixture to produce lightweight concrete. The NaOH solution was prepared by dilute NaOH pellets with distilled water. The reactives were mixed to produce a homogeneous mixture, which was placed into a 50 mm mold and cured at two different curing temperatures (60 °C and room temperature), for 24 hours. After the curing process, the strengths of the samples were tested on days 1, 7, and 28. The water absorption, porosity, chemical composition, microstructure, XRD and FTIR analyses were studied. The results showed that the sample which was cured at 60 °C (LW2) produced the maximum compressive strength for all tests, (11.03 MPa, 17.59 MPa, and 18.19 MPa) for days 1, 7, and 28, respectively. Also, the water absorption and porosity of LW2 were reduced by 6.78% and 1.22% after 28 days, respectively. The SEM showed that the LW2 sample had a denser matrix than LW1. This was because LW2 was heat cured, which caused the geopolymerization rate to increase, producing a denser matrix. However for LW1, microcracks were present on the surface, which reduced the compressive strength and increased water absorption and porosity.

2 16

Publication

The role of sodium surface species on electrochemical promotion of catalysis in a Pt/YSZ system: The case of ethylene oxidation

( 2013-04-23)

Naimah Ibrahim

;

Danai Poulidi

;

Ian S. Metcalfe

The role of sodium addition as foreign (impurity) species on the electrochemical promotion of ethylene oxidation in a Pt/YSZ system was investigated. It was found that the presence of sodium surface species on the catalyst surface can significantly affect its catalytic and electrocatalytic properties, but there is no clear evidence at this stage that such species are necessary for the observation of EPOC. Under negative polarisation, low coverage sodium was found to have a pronounced effect on the electrochemical promotion of ethylene oxidation as an electronic promoter. The reaction changed behaviour from electrophilic at low sodium coverage (0.11%) and low to intermediate oxygen partial pressure (pO2 ⩽ 3.0 kPa) to electrophobic at high sodium coverage (65%) and under high oxygen partial pressures (pO2 = 8.0 kPa). In between the two sets of conditions, the reaction showed volcano-type behaviour depending on the coverage of sodium and gas-phase oxygen partial pressure.

14 2

Publication

Analysis of short time period of operation of horizontal ground heat exchangers

( 2015)

Salsuwanda Selamat

;

Akio Miyara

;

Keishi Kariya

Ground source heat pump (GSHP) systems have been proven to have higher efficiency compared to conventional air source heat pump systems for space heating and cooling applications. While vertical ground heat exchangers (GHE) are favorable in GSHP installation, this type of configuration requires higher capital costs as opposed to horizontal configuration. Numerical simulation has been used to accurately predict the thermal performance of GHE. In this paper, numerical analysis of thermal performance for slinky horizontal GHE loops in different orientations and operation modes is discussed. It was found that the loop orientation is not so important due to the little effect it has on thermal performance. While the mean heat exchange rate of copper loop increases 48% compared to HDPE loop, the analysis supports the common claim that heat exchange rate is predominantly limited by the thermal conductivity of the ground. With the same amount of circulation work, the mean heat exchange rate increases by 83%–162% when operated in parallel loops operations. The performance in these operations can be further optimized to 10%–14% increase when spacing between adjacent loops was provided. The spacing helps to minimize interference of heat flow that would penalize the overall thermal performance.

6 6

Publication

Optimization of NaOH molarity, LUSI mud/alkaline activator, and Na₂SiO₃/NaOH ratio to produce lightweight aggregate-based geopolymer

( 2015)

Rafiza Abd Razak

;

Mohd. Mustafa Al Bakri Abdullah

;

Djwantoro Hardjito

;

Kamarudin Hussin

;

Khairul Azwan Ismail

;

Zarina Yahya

This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na₂SiO₃/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced.

1 12

Publication

A proposed aerobic granules size development scheme for aerobic granulation process

( 2015-04)

Farrah Aini Dahalan

;

Norhayati Abdullah

;

Ali Yuzir

;

Gustaf Olsson

;

Myzairah Salmiati

;

Mohd Fadhil Mohd Hamdzah

;

Siti Aqlima Din

;

Khalilah Abdul Ahmad

;

Aznah Nor Khalil

;

Zainura Zainon Anuar

;

Zaini Noor

Aerobic granulation is increasingly used in wastewater treatment due to its unique physical properties and microbial functionalities. Granule size defines the physical properties of granules based on biomass accumulation. This study aims to determine the profile of size development under two physicochemical conditions. Two identical bioreactors namely Rnp and Rp were operated under non-phototrophic and phototrophic conditions, respectively. An illustrative scheme was developed to comprehend the mechanism of size development that delineates the granular size throughout the granulation. Observations on granules’ size variation have shown that activated sludge revolutionised into the form of aerobic granules through the increase of biomass concentration in bioreactors which also determined the changes of granule size. Both reactors demonstrated that size transformed in a similar trend when tested with and without illumination. Thus, different types of aerobic granules may increase in size in the same way as recommended in the aerobic granule size development scheme.

Publication

Characterisation and evaluation of trimesic acid derivatives as disulphide cross-linked polymers for potential colon targeted drug delivery

( 2017)

Siti Nur Aishah Mat Yusuf

;

Ng, Yoke Mooi

;

Ayub, Asila Dinie

;

Ngalim, Siti Hawa

;

Vuanghao Lim

Discovery and use of biocompatible polymers offers great promise in the pharmaceutical field, particularly in drug delivery systems. Disulphide bonds, which commonly occur in peptides and proteins and have been used as drug-glutathione conjugates, are reductively cleaved in the colon. The intrinsic stability of a disulphide relative to thiol groups is determined by the redox potential of the environment. The objective of this study was to synthesise a trimesic acid-based disulphide cross-linked polymer that could potentially be used for targeted delivery to the colon. The monomer was synthesised by an amide coupling reaction between trimesic acid and (triphenylmethyl) thioethylamine using a two-step synthesis method. The s-trityl group was removed using a cocktail of trifluoroacetic acid and triethylsilane to expose the thiols in preparation for further polymerisation. The resulting polymers (P10, P15, P21, P25, and P51, generated using different molar ratios) were reduced after 1.5 h of reduction time. Scanning electron microscopy images of the polymers showed spherical, loose, or tight patterns depending on the molar ratio of polymerisation. These polymers also exhibited efficient dissolution under various gastrointestinal conditions. Of the five polymers tested, P10 and P15 appeared to be promising drug delivery vehicles for poorly soluble drugs, due to the hydrophobic nature of the polymers.

1 5

Publication

Effect of different vinyl-acetate contents in hybrid SBS-EVA modified bitumen

(Elsevier, 2020)

Ilya Joohari

;

Filippo Giustozzi

Publication

Effects of magnesium ions in microbial cells adhesion of attached growth system for the enhancement of biogas production

(Penerbit UTM Press, 2020)

Nabilah Aminah Lutpi

;

Wong Yee Shian

;

Tengku Nuraiti Tengku Izhar

;

Yiek Wee Kiong

This research aims to improve the biogas production by employing cell immobilisation technique under thermophilic conditions. The thermophilic fermentative biogas production was carried out by immobilising the anaerobic sludge obtained from palm oil mill treatment plant on granular activated carbon (GAC) in repeated batch mode. Different concentration of magnesium ions (Mg2+) (0.25, 0.5, 0.75, 1.0 and 1.5 g/l) on biogas production was investigated at 60°C with an initial sucrose concentration of 5 g/l as feedstock. The effect of Mg2+ supplementation at the initial stage of immobilisation process is important to increase the formation of biofilm in the attached growth system. This study had found that Mg2+ could enhance the biogas production capacity with optimum Mg2+ concentration of 0.75 g/l.

Publication

Lesson learned in maintaining the precast concrete buildings

(Emerald Publishing Ltd., 2020)

Zul-Atfi Ismail

Purpose: The purpose of this study is to identify existing weaknesses in precast concrete building maintenance and how to overcome it. The contemporary practice of conventional methods in the pre-cast concrete (PC) building maintenance entails many issues such as PC component aesthetic and structural defects, no integration between maintenance systems and lack the intelligent capabilities of linking defect diagnosis operations in maintenance due to poor service delivery and defect repetition. A key problem impeding the widespread adoption of emerging technologies is the lack of competent contractor supporting the effectiveness of implemented information and communication technology than conventional methods and the returns on investment. Design/methodology/approach: The shortcomings of conventional methods are assessed from the perspective of PC buildings. Several data were collected through a case study of eight PC buildings from high-rise and complex buildings. Findings: The conventional methods had significantly little emphasis on defect diagnosis tools. It had also increased the inadequate strategic decision making to analyse information in improving the maintenance project outcomes for PC building. Originality/value: Building information modelling tools is suggested from findings and lessons learned as a good practice to reduce the repetition of defects on the design specification used and construction practiced.

1 5

Publication

Prediction of pressuremeter modulus (E M) using GMDH neural network: a case study of Kenny Hill Formation

( 2020-05-01)

Mohd Faiz Mohammad Zaki

;

Ismail M.A.M.

;

Govindasamy D.

;

Leong F.C.P.

Soil investigation (SI) work is a process of collecting subsurface ground profile information in evaluating soil engineering properties for a construction project. The standard penetration method (SPT) is widely accepted worldwide as a feasible and relatively inexpensive method over other field tests. Pressuremeter test (PMT), on the other hand, is costly and more popular in situ method in interpreting soil deformation behavior. Considering SPT is available in almost site investigation works for all sizes of project, it was tempting to establish the correlation between SPT and PMT results, specifically in local geologic setting. The study was conducted in Kenny Hill Formation, Kuala Lumpur, Malaysia. The correlation established in this study is between pressuremeter modulus (EM) and SPT blow count (N60). In addition to in situ methods, the physical properties of soil extruded from boreholes were tested in geotechnical laboratories to determine soil properties, such as particle size distribution, liquid limit, and plastic limit. These parameters need to be considered during prediction of EM. Group method of data handling (GMDH) neural network has been used to achieve this objective. The mean absolute error (MAE) results show that the GMDH neural networks produce values of 8.04 and 8.59 for training and testing. The root mean square error (RMSE) yields 10.61 and 10.84 for training and testing, respectively. Further, the results of the coefficients of determination (R2) are 0.794 and 0.726 for training and testing demonstrates a good correlation exists between predicted and measured values. Based on the GMDH results, N60, sand, and clay are required input variables for determination of EM.

1 13

Publication

A State-of-the-Art review on innovative geopolymer composites designed for water and wastewater treatment

( 2021)

Ismail Luhar

;

Salmabanu Luhar

;

Mohd. Mustafa Al Bakri Abdullah

;

Rafiza Abd Razak

;

Petrica Vizureanu

;

Andrei Victor Sandu

;

Petre-Daniel Matasaru

There is nothing more fundamental than clean potable water for living beings next to air. On the other hand, wastewater management is cropping up as a challenging task day-by-day due to lots of new additions of novel pollutants as well as the development of infrastructures and regulations that could not maintain its pace with the burgeoning escalation of populace and urbanizations. Therefore, momentous approaches must be sought-after to reclaim fresh water from wastewaters in order to address this great societal challenge. One of the routes is to clean wastewater through treatment processes using diverse adsorbents. However, most of them are unsustainable and quite costly e.g. activated carbon adsorbents, etc. Quite recently, innovative, sustainable, durable, affordable, user and eco-benevolent Geopolymer composites have been brought into play to serve the purpose as a pretty novel subject matter since they can be manufactured by a simple process of Geopolymerization at low temperature, lower energy with mitigated carbon footprints and marvellously, exhibit outstanding properties of physical and chemical stability, ion-exchange, dielectric characteristics, etc., with a porous structure and of course lucrative too because of the incorporation of wastes with them, which is in harmony with the goal to transit from linear to circular economy, i.e., “one’s waste is the treasure for another”. For these reasons, nowadays, this ground-breaking inorganic class of amorphous alumina-silicate materials are drawing the attention of the world researchers for designing them as adsorbents for water and wastewater treatment where the chemical nature and structure of the materials have a great impact on their adsorption competence. The aim of the current most recent state-of-the-art and scientometric review is to comprehend and assess thoroughly the advancements in geo-synthesis, properties and applications of geopolymer composites designed for the elimination of hazardous contaminants viz., heavy metal ions, dyes, etc. The adsorption mechanisms and effects of various environmental conditions on adsorption efficiency are also taken into account for review of the importance of Geopolymers as most recent adsorbents to get rid of the death-defying and toxic pollutants from wastewater with a view to obtaining reclaimed potable and sparkling water for reuse offering to trim down the massive crisis of scarcity of water promoting sustainable water and wastewater treatment for greener environments. The appraisal is made on the performance estimation of Geopolymers for water and wastewater treatment along with the three-dimensional printed components are characterized for mechanical, physical and chemical attributes, permeability and Ammonium (NH4+) ion removal competence of Geopolymer composites as alternative adsorbents for sequestration of an assortment of contaminants during wastewater treatment.

Publication

Assessment of the suitability of ceramic waste in geopolymer composites: an appraisal

( 2021)

Ismail Luhar

;

Salmabanu Luhar

;

Mohd. Mustafa Al Bakri Abdullah

;

Marcin Nabiałek

;

Andrei Victor Sandu

;

Janusz Szmidla

;

Anna Jurczyńska

;

Rafiza Abdul Razak

;

Ikmal Hakem A Aziz

;

Noorina Hidayu Jamil

;

Laila Mardiah Deraman

Currently, novel inorganic alumino-silicate materials, known as geopolymer composites, have emerged swiftly as an ecobenevolent alternative to contemporary ordinary Portland cement (OPC) building materials since they display superior physical and chemical attributes with a diverse range of possible potential applications. The said innovative geopolymer technology necessitates less energy and low carbon footprints as compared to OPC-based materials because of the incorporation of wastes and/or industrial byproducts as binders replacing OPC. The key constituents of ceramic are silica and alumina and, hence, have the potential to be employed as an aggregate to manufacture ceramic geopolymer concrete. The present manuscript presents a review of the performance of geopolymer composites incorporated with ceramic waste, concerning workability, strength, durability, and elevated resistance evaluation.

Publication

Photocatalytic degradation of sugarcane vinasse using ZnO photocatalyst: operating parameters, kinetic studies, phytotoxicity assessments, and reusability

( 2021)

Kee Wei Chin

;

Wong Yee Shian

;

Ong Soon An

;

Nabilah Aminah Lutpi

;

Sam Sung Ting

;

Audrey Chai Yee Chieh

;

Kim-Mun Eng

Photocatalytic degradation performance is highly related to optimized operating parameters such as initial concentration, pH value, and catalyst dosage. In this study, the impact of various parameters on the photocatalytic degradation of anaerobi‑ cally digested vinasse (AnVE) has been determined through decolourization and chemical oxygen demand (COD) reduction efciency using zinc oxide (ZnO) photocatalyst. In this context, the application of photocatalytic degradation in treating sugarcane vinasse using ZnO is yet to be explored. The COD reduction efciency and decolourization achieved 83.40% and 99.29%, respectively, under the conditions of 250 mg/L initial COD concentration, pH 10, and 2.0 g/L catalyst dosage. The phytotoxicity assessment was also conducted to determine the toxicity of AnVE before and after treatment using mung bean (Vigna radiata). The reduction of root length and the weight of mung bean indicated that the sugarcane vinasse contains enormous amounts of organic substances that afect the plant's growth. The toxicity reduction in the AnVE solution can be proved by UV–Vis absorption spectra. Furthermore, the catalyst recovery achieved 93% in the reusability test. However, the COD reduction efciency and decolourization were reduced every cycle. It was due to the depletion of the active sites in the catalyst with the adsorption of organic molecules. Thus, it can be concluded that the photocatalytic degradation in the treatment of AnVE was efective in organic degradation, decolorization, toxicity reduction and can be reused after the recovery process.

2 13

Publication

Improving failure risk by better planning and safety for precast beam-to-column connection elements using physical internet-enabled building information modeling technology: a Malaysian case study

(Emerald Publishing Ltd., 2022)

Zul-Atfi Ismail

Purpose: The purpose of this paper is to show that the growing global trend of quality assurance indicates the potential of precast concrete (PC) to improve construction quality and productivity, reduce wasteful construction, and achieve design standardization and to accelerate construction time. However, its current approach for dynamic characteristics, such as stiffness and displacement on beam-column connection system design, is not effective in achieving the required quality and operational requirements. Design/methodology/approach: A design tool based on the literature and data analysis in product planning and safety is proposed for the practice of PC building construction. Findings: The results reveal the need for improvement of PC building performance in the construction industry, especially for the beam-column connection system. The issues include improper design, improper specification and defective concrete and steel components compared to other manufacturing methods. Originality/value: A novel and sophisticated technique based on physical internet-enabled building information modeling (PI-BIM) is proposed to improve the planning process and safety for PC buildings in Malaysia

Publication

A critical study of the existing issues in circular economy practices during movement control order: can BIM fill the gap?

(Emerald, 2022)

Zul-Atfi Ismail

The improper evaluation and information management of circular economy (CE) (i.e. design, planning, supply chain, waste pile and material hazard) is critical for public health and is a major problem in the waste management of precast concrete (PC) building manufacture and construction and demolition wastes industry. The CE model is particularly problematic for PC building construction projects where the standard practices for the total number of waste building materials are not appropriate and do not match the safe disposal design specification, such as the recent number increase in the Malaysian illegal construction waste pile during the Movement Control Order (11 March 2021, about 5 out of 29 landfills related to states enforcing Act 672). The study aims to develop a framework application (i.e. Building Information Modelling [BIM]) that supports intelligent waste recycling management and sophisticated CE model system solutions. Design/methodology/approach: Thus, the development of a new BIM-based programming algorithm approach is proposed for optimising CE in accordance with the needs of the current PC building construction schemes. As a precursor to this study, the concepts of CE practices are reviewed and the main features of BIM tools and techniques currently being employed on such projects are presented. Findings: Sophisticated CE system solutions are described as an essential component of this optimisation to reduce the amount of waste generated at the end of the life cycle of PC building construction projects and to better manage the resources used throughout it. Originality/value: Finally, the potential for a research framework for developing such a system in the future is presented.

Publication

Reclamation and Reutilization of Incinerator Ash in Artificial Lightweight Aggregate

( 2022)

Norlia Mohamad Ibrahim

;

Roshazita Che Amat

;

Mustaqqim Abdul Rahim

;

Nur Liza Rahim

;

Abdul Rahim Abdul Razak

This study focused on the reclamation of ash from incineration process and development of new artificial lightweight aggregate (LWA) that have comparable properties with existing natural coarse aggregate. The main objective of this study is to examine potential use of recycled municipal solid waste incineration (MSWI) ash as raw material in LWA production with a method of cold-bonded pelletization. Two types of incineration ash which is bottom ash (BA) and fly ash (FA) were collected from Cameron Highland Incineration Plant, Malaysia. The properties of BA and FA are studied by means of X-Ray Fluorescence (XRF) and microstructure of these ashes were inspected using Scanning Electron Microscope (SEM). The properties of BALA and FALA produced in this study is examined including loose bulk density, water absorption and aggregate impact value (AIV). From the results of both types of artificial LWA, the lowest loose bulk density of BALA is BALA50 with 564.14 kg/m3 and highest is at 831.19 kg/m3 . For FALA50, lowest loose bulk density is 573.64 kg/m3 and highest is 703.35 kg/m3 . Water absorption of BALA and FALA is quite similar with one another in with the value of 23.8% and 22.6%, respectively. Generally, FALA have better qualities of LWA comparing with BALA with lower bulk density and water absorption and can be categorized as strong aggregate. In summary, reclamation and reutilization of incinerator ash has generated acceptable qualities for artificial LWA. Both types of BA and FA shown a great potential to be recycled as additional materials in artificial aggregate production.

16 19

Publication

Metakaolin/sludge based geopolymer adsorbent on high removal efficiency of Cu2+

( 2022)

Pilomeena Arokiasamy

;

Mohd. Mustafa Al Bakri Abdullah

;

Shayfull Zamree Abd. Rahim

;

Mohd Remy Rozainy Mohd Arif Zainol

;

Mohd Arif Anuar Mohd Salleh

;

Marwan Kheimi

;

Jitrin Chaiprapa

;

Andrei Victor Sandu

;

Petrica Vizureanu

;

Rafiza Abd Razak

;

Noorina Hidayu Jamil

Activated carbon (AC) has received a lot of interest from researchers for the removal of heavy metals from wastewater due to its abundant porous structure. However, it was found unable to meet the required adsorption capacity due to its amorphous structure which restricts the fundamental studies and structural optimization for improved removal performance. In addition, AC is not applicable in large scale wastewater treatment due its expensive synthesis and difficulty in regeneration. Thus, the researchers are paying more attention in synthesis of low cost geopolymer based adsorbent for heavy metal removal due its excellent immobilization effect. However, limited studies have focused on the synthesis of geopolymer based adsorbent for heavy metal adsorption by utilizing industrial sludge. Thus, the aim of this research was to develop metakaolin (MK) based geopolymer adsorbent with incorporation of two types of industrial sludge (S1 and S3) that could be employed as an adsorbent for removing copper (Cu2+) from aqueous solution through the adsorption process. The effects of varied solid to liquid ratio (S/L) on the synthesis of metakaolin/sludge based geopolymer adsorbent and the removal efficiency of Cu2+ by the synthesis adsorbent were studied. The raw materials and synthesized geopolymer were characterized by using x-ray fluorescence (XRF), x-ray diffraction (XRD), scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and micro XRF. The concentration of Cu2+ before and after adsorption was determined by atomic absorption spectroscopy (AAS) and the removal efficiency was calculated. The experimental data indicated that the synthesized geopolymer at low S/L ratio has achieved the highest removal efficiency of Cu2+ about 99.62 % and 99.37 % at 25 %:75 % of MK/S1 and 25 %:75 % of MK/S3 respectively compared to pure MK based geopolymer with 98.56 %. The best S/

1 16

Publication

Mechanical properties of Fly Ash-Based geopolymer concrete incorporation Nylon66 Fiber

( 2022)

Muhd Hafizuddin Yazid

;

Meor Ahmad Faris bin Meor Ahmad Tajudin

;

Mohd. Mustafa Al Bakri Abdullah

;

Muhammad Shazril I. Ibrahim

;

Rafiza Abdul Razak

;

Dumitru Doru Burduhos Nergis

;

Diana Petronela Burduhos Nergis

;

Omrane Benjeddou

;

Khanh-Son Nguyen

This study was carried out to investigate the effect of the diamond-shaped Interlocking Chain Plastic Bead (ICPB) on fiber-reinforced fly ash-based geopolymer concrete. In this study, geopolymer concrete was produced using fly ash, NaOH, silicate, aggregate, and nylon66 fibers. Characterization of fly ash-based geopolymers (FGP) and fly ash-based geopolymer concrete (FRGPC) included chemical composition via XRF, functional group analysis via FTIR, compressive strength determination, flexural strength, density, slump test, and water absorption. The percentage of fiber volume added to FRGPC and FGP varied from 0% to 0.5%, and 1.5% to 2.0%. From the results obtained, it was found that ICBP fiber led to a negative result for FGP at 28 days but showed a better performance in FRGPC reinforced fiber at 28 and 90 days compared to plain geopolymer concrete. Meanwhile, NFRPGC showed that the optimum result was obtained with 0.5% of fiber addition due to the compressive strength performance at 28 days and 90 days, which were 67.7 MPa and 970.13 MPa, respectively. Similar results were observed for flexural strength, where 0.5% fiber addition resulted in the highest strength at 28 and 90 days (4.43 MPa and 4.99 MPa, respectively), and the strength performance began to decline after 0.5% fiber addition. According to the results of the slump test, an increase in fiber addition decreases the workability of geopolymer concrete. Density and water absorption, however, increase proportionally with the amount of fiber added. Therefore, diamond-shaped ICPB fiber in geopolymer concrete exhibits superior compressive and flexural strength.

1 11

Publication

The stiffness of steel-wood-steel connection loaded parallel to the grain

( 2022-01-01)

Nur Liza Rahim

;

Raftery G.

;

Quenneville P.

;

Ing D.S.

;

Nabialek M.

;

Jaya R.P.

;

Norlia Mohamad Ibrahim

;

Mohd. Mustafa Al Bakri Abdullah

;

Śliwa A.

In Eurocode 5, the stiffness equation for bolted steel-wood-steel is stated as a function of wood density and fastener diameter only. In this research, an experimental study on various configurations of tested bolted steel-wood-steel (SWS) connections has been undertaken to predict the initial stiffness of each connection. In order to validate the Eurocode 5 stiffness equation, tests on 50 timber specimens (40 glued laminated timbers and 10 laminated veneer lumbers (LVL)) with steel plates were undertaken. The number of bolts was kept similar and the connector diameter, timber thickness, and wood density were varied. The results obtained in the experimental tests are compared with those obtained from the Eurocode 5 stiffness equation. From the analysis, it is signified that the stiffness equation specified in Eurocode 5 for bolted SWS connections does not adequately predict the initial stiffness. The results from Eurocode 5 stiffness equation are very far from the experimental values. The ratio of stiffness equation to experimental results ranges from 3.48 to 4.20, with the average at 3.77, where the equation over-predicted the experimental stiffness value for the connection. There is a need to consider or incorporated other parameters such as geometric configurations in Eurocode 5 stiffness equation to improve the ratio with the experimental data.

3 2

Journal Articles

Permanent URI for this collection

Browse

Browse

Browsing Journal Articles by Issue Date

Results Per Page

Sort Options