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The interest in the use of mathematical models for the simulation of hydrological processes has largely increased especially in the prediction of runoff. It is the subject of extreme research among engineers and hydrologists. This study attempts to develop a simple conceptual model that reflects the features of the arid environment where the availability of hydrological data is scarce. The model simulates an hourly streamflow hydrograph and the peak flow rate for any given storm. Hourly rainfall, potential evapotranspiration, and streamflow record are the significant input prerequisites for this model. The proposed model applied two (2) different hydrologic routing techniques: the time area curve method (wetted area of the catchment) and the Muskingum method (catchment main channel). The model was calibrated and analyzed based on the data collected from arid catchment in the center of Jordan. The model performance was evaluated via goodness of fit. The simulation of the proposed model fits both (a) observed and simulated streamflow and (b) observed and simulated peak flow rate. The model has the potential to be used for peak discharges’ prediction during a storm period. The modeling approach described in this study has to be tested in additional catchments with appropriate data length in order to attain reliable model parameters.

This review provides an intensive overview of flame retardant coating systems. The occurrence of flame due to thermal degradation of the polymer substrate as a result of overheating is one of the major concerns. Hence, coating is the best solution to this problem as it prevents the substrate from igniting the flame. In this review, the descriptions of several classifications of coating and their relation to thermal degradation and flammability were discussed. The details of flame retardants and flame retardant coatings in terms of principles, types, mechanisms, and properties were explained as well. This overview imparted the importance of intumescent flame retardant coatings in preventing the spread of flame via the formation of a multicellular charred layer. Thus, the intended intumescence can reduce the risk of flame from inherently flammable materials used to maintain a high standard of living.

This paper reviews the difference between glazed and unglazed ceramic and porcelain tiles, other than the fact that glazed tiles undergo an additional phase in the firing process. Both tiles are made of clay and burned in a kiln, but porcelain is a particular sort of ceramic. Porcelain clays have a greater density and are burnt at a higher temperature for a longer period time than ceramic clays. This makes it denser and more durable than ceramic tile. The variation in components and production process results in tiles with distinct properties. Although glazed ceramic and porcelain tiles are a little less robust in terms of density and thickness than their unglazed counterpart, they allow for a wider range of styles and colours. Some varieties of glazed tile are fired at higher temperatures than others, and therefore are harder as well. Unglazed tiles are denser and thicker than glazed tiles due to their unfinished appearance. In addition to safety, ceramic and unglazed ceramic tiles are scratch resistant. Because they have the colour of the mineral deposits from which the clay was originally mined, these tiles have a natural aesthetic. The major difference between ceramic and porcelain tiles is how it’s made. In conclusion, porcelain tiles are superior to ceramic tiles based on these reviews.

Concrete is commonly used as a construction material because of the important properties is broadly utilized as development materials within the development segment. Unfortunately, the component of cement within the concrete results in many side-effects such as affecting the environment. Therefore, this paper presented the review of essential to seek out an alternative materials which may be utilized as cement replacement materials by reutilizing agricultural waste ash. Selected agricultural waste ash which are Palm Oil Fuel Ash (POFA), Rice Husk Ash (RHA), Groundnut Shell Ash (GSA), Sugarcane Bagasse Ash (SBA) and Oyster Shell Powder (OSP) were review in terms of their compressive strength and slump height of the mixture. The treated palm oil ash which is going to be used as partial cement replacement material for the proper design mix and optimal ash replacement. The replacement percentage of palm ash in the concrete were set at 10%, 20%, and 30% by weight with the optimal replacement ratio of the supplementary cementitious content. Palm Oil Fuel Ash (POFA) is a material that having sufficient requirements to be a good pozzolana and cementitious material according to ASTMC618 in terms of chemical composition. POFA is a material that consists high silica contents. By having more silica contents, it will help to improve the properties, in particular its compressive strength, bond strength, and abrasion resistance. After conducting several research, it was concluded that the optimal replacement for POFA is 20% and it is better to have finer POFA. POFA also proved some of the important properties is the CO2 emissions would be reduce.

The application of coal ash (CA) in construction industries has grown rapidly, posing risk to the environment due to heavy metals leaching from the material. This research presents a simulation of ecological risk assessment and model risk indicators (ERI) of leached heavy metals (lead (Pb), copper (Cu), zinc (Zn) and arsenic (As)) from CA (FA: fly ash and BA: bottom ash) via response surface methodology (RSM). The ERI values were based on quantified leached heavy metals from the toxicity characteristic leaching procedure (TCLP-1311) and synthetic precipitation leaching procedure (SPLP-1312). The ecological risk index (RI ) values for TCLP were 10.27 × 100 (FA), 9.91 × 100 (BA) and 12.58 × 100 (FA + BA), whereas RI for SPLP were 10.34 × 100 (FA), 9.90 × 100 (BA) and 12.61 × 100 (FA + BA). Twenty-nine combinations of operations were evaluated based on Box-Behnken design with ERI as the response variable. The established model risk indicator (i.e., coded and actual factors) of Pb, Cu, Zn and ‘As’ showed significant model terms that describe their relationship very well, perfectly fit to the corresponding ERI (sum of squares = 0.4160, F value = 682,375.55) with probability of 0.01% for an F-value could occur due to noise. The optimized models were validated with error percentage of less than 5%. The established ERI models showed significant model terms and will be useful for ecological monitoring of CA application in construction industries.

The utilization of cenosphere by-product of fly ash as a substitution of sand in concrete is an effective way to reduce thermal conductivity. This study investigates the mechanical and thermal properties of cenosphere substituted in the lightweight concrete. Cenosphere is the recycled material and possesses good thermal insulation properties. Study objectified replacement of sand over the FA cenospher to study the mechanical and thermal properties of the concrete. Experimental setup of the study 10%, 20% and 30% sand by weight is replaced with cenosphere. Concrete specimen prepares and cured for the period of 3, 7 and 28 d. Compressive strength of the concrete is analyzed for 3-7 and 28 d where tensile strength is analyzed for 28 d. Study shows significant improvement in the compressive strength and tensile strength. Thermal conductivity is analyzed for 28 d cured concrete samples using Heat flow FOX-50 instrument. Thermal conductivity reduces by 35% with the replacement of 30% sand over cenosphere which shows the significant reduction. Due to the lower density of cenosphere density of concrete samples reduced which is one of the leading factors to the lower thermal conductivity. Study concluded by replacement of 30% FA cenosphere compressive strength increased conversely thermal conductivity and density of the concrete specimen has reduced.

In recent years, the production of cement has grown globally in a very rapid manner due to the modernization of the world we live in, and after fossil fuels and land-use change, cement production is the third-largest source of anthropogenic emissions of carbon dioxide, CO2. Cement being the primary binding material for concrete and with the prospects for the concrete industry continues to grow so will the emissions of CO2. Hence, a method to reduce the CO2 production while keeping up with the progression of the concrete industry is very crucial in current times. This is where CO2 sequestration comes in. It is a process where CO2 is converted into a mineral which will then be trapped into the concrete forever. Required data to carry out the research between CO2 sequestered concrete and concrete without CO2 have been observed, obtained and tabulated as necessary. These data are then used to compare the concrete samples with one another and also prove the theoretical effects of CO2 exposure to concrete. Hence, experimental results on the compressive strength of the concrete samples for 7, 14 and 28 days has also been tabulated, graphed and further disputed. The objective of this research is mainly to determine the compressive strength of CO2 sequestered concrete in comparison with concrete without CO2 in order to decrease the effects the concrete industry has on the environment. The compressive strength of concrete samples with sequestration of CO2 gas is expected to be higher than of the concrete without CO2.

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic compounds, composed of benzene rings. The objective of this research was to identify the optimum condition for the degradation of PAHs contaminated water using photo-Fenton oxidation process via response surface methodology (RSM). Aqueous solution was prepared and potable water samples were collected from water treatment plants in Perak Tengah, Perak, Malaysia in September 2016. The reaction time, pH, molarity of H2O2 and FeSO4 were analyzed followed by RSM using aqueous solution. A five level central composite design with quadratic model was used to evaluate the effects and interactions of these parameters. The response variable was the percentage of total organic carbon (TOC) removal. PAHs quantification was done using gas chromatography mass spectrometry analysis. The regression line fitted well with the data with R2 value of 0.9757. The lack of fit test gives the highest value of Sum of Squares (15,666.64) with probability F value 0.0001 showing significant quadratic model. The optimum conditions were established corresponding to the percentage of TOC removal. The PAHs removal efficiency for potable water samples ranged from 76.4% to 91% following the first order of kinetic rates with R2 values of >0.95. Conventional water treatment techniques are not effective for PAHs removal. Thus, advanced oxidation processes may be considered as an alternative to conventional water treatment techniques in Malaysia and other developing countries.

The potassium (K) and sodium (Na) elements in banana are needed for hydration reaction that can enhance the strength properties of concrete. This research aims (a) to determine the material engineering properties of banana skin ash (BSA) and concrete containing BSA, (b) to measure the strength enhancement of concrete due to BSA, and (c) to identify optimal application of BSA as supplementary cement materials (SCM) in concrete. The BSA characterization were assessed through X-ray fluorescence (XRF) and Blaine’s air permeability. The workability, compressive strength, and microstructures of concrete containing BSA were analysed using slump test, universal testing machine (UTM) and scanning electron microscope (SEM). A total of 15 oxides and 19 non-oxides elements were identified in BSA with K (43.1%) the highest and Na was not detected. At 20 g of mass, the BSA had a higher bulk density (198.43 ± 0.00 cm3) than ordinary Portland cement (OPC) (36.32 ± 0.00 cm3) indicating availability of large surface area for water absorption. The concrete workability was reduced with the presence of BSA (0% BSA: > 100 mm, 1% BSA: 19 ± 1.0 mm, 2%: 15 ± 0.0 mm, 3% BSA: 10 ± 0.0 mm). The compressive strength increased with the number of curing days. The concrete microstructures were improved; interfacial transition zones (ITZ) decreased with an increase of BSA. The optimal percentage of BSA obtained was at 1.25%. The established model showed significant model terms (Sum of Squares = 260.60, F value = 69.84) with probability of 0.01% for the F-value to occur due to noise. The established model is useful for application in construction industries.

This paper presents on the low velocity impact loading on plain slab concrete. There are three different thicknesses of concrete slabs; namely 20 mm, 30 mm, and 40 mm, all of which have been subjected to 1 blow of impact from 1.25 kg steel ball per slab. The resulting deflections and stresses on the concrete midspan was then observed. It was found that the highest deflection occurs for the concrete slab with the 20 mm thickness with a value of 9.965 mm, while the lowest deflection was found to be at 4.157 mm for the slab thickness of 40 mm. The highest mid-span stress occured at 20 mm slab for 500 mm drop height. During impact it was observed the slab is still in elastic linear region.

In Malaysia, seven coal-fired power plants under Tenaga Nasional Malaysia continuously produce around 790 tons of solid residue namely coal bottom ash (CBA) per day. The aim of this research was to optimize concrete mix design containing CBA as cement replacement via statistical modelling, response surface methodology (RSM). The fineness, water cement ratio and percentage inclusion of ground coal bottom ash (GCBA) were analyzed followed by RSM resulted on compressive strength at 28 days. Coal bottom ash was ground to three different sizes; 45 μm, 75 μm and 100 μm, water cement ratio was set to three different value; 0.40, 0.45 and 0.50 and percentage of GCBA inclusion was set up to three different percentages; 5%, 10% and 15%. Results indicate that GCBA increase compressive strength at 28 days regardless of different values of each variables. It is found that with the increasing percentage of inclusion of GCBA with lower water cement ratio will lower the compressive strength due to its characteristic of water absorbance. In conclusion, with adequate water cement ratio, and optimum percentage of GCBA, complete hydration process will be achieved, and the development of compressive strength is significantly increase.

Carbon dioxide, CO2 accounts for most of the emission from all the types of greenhouse gasses in the world. The ability of CO2 to remain longer than other greenhouse gases and the convenience of producing CO2 has resulted in its high projection in a yearly manner. The prime factor for the emission of CO2 are from the actions of human beings. One such human act is the concrete industry. Total emissions from the concrete industry could therefore contribute as much as 8% of global CO2 emissions. Sequestered CO2 in concrete can provide an impact on reducing the carbon footprint and is also able to improve the compressive strength of concrete. During this process, the sequestered carbon dioxide chemically reacts with cement to produce a mineral, trapping carbon dioxide gas in the concrete. Hence, sequestering carbon dioxide gas in concrete does not only on a bigger scale reduces carbon footprint, but it also reduces the impact the construction industry has on the environment. This paper presents a detailed review on the chemical reaction that takes place during the sequestration of carbon dioxide and the research published on the effects of carbon dioxide sequestered concrete on its properties. The impact this process has on the concrete industry and the environment is discussed in this paper.

The rapid deformation caused by alkali–silica reaction may cause major problems in concrete structures. Main factors that affect ASR include the relative humidity, alkali and silica content, temperature, and porosity of the concrete. The vast numbers of influencing factors make ASR relationship a complex phenomenon to understand. Investigation of the mechanical deformation of the structure can be achieved by applying the theory of continuum damage mechanics. Prediction of the physical and chemical behavior of a structure can be achieved using damage mechanics, making it an appropriate method to study the behavior of the structure under the influence of alkali–silica reactivity. Hence, solution of the damage model as well as simulation of the ASR phenomenon is critically needed. In this research, an engineering example of a thermo-chemo-hygro-mechanical model of a concrete gravity dam at the macroscale will be studied for varying environmental conditions of temperature and relative humidity using the finite element method. Investigations found that temperature as well as relative humidity influences the latency and characteristic time constants, which indicates that the ASR expansion rapidity is dependent on the heat and moisture diffusion lengths into the structure, causing heterogeneous damage along the cross section of the macroscale structure according to the temperature distribution as well as relative humidity.

Carbon dioxide, CO2 accounts for most of the emission from all the types of greenhouse gasses in the world. The ability of CO2 to remain longer than other greenhouse gases and the convenience of producing CO2 has resulted in its high projection in a yearly manner. The prime factor for the emission of CO2 are from the actions of human beings. One such human act is the concrete industry. Total emissions from the concrete industry could therefore contribute as much as 8% of global CO2 emissions. Sequestered CO2 in concrete can provide an impact on reducing the carbon footprint and is also able to improve the compressive strength of concrete. During this process, the sequestered carbon dioxide chemically reacts with cement to produce a mineral, trapping carbon dioxide gas in the concrete. Hence, sequestering carbon dioxide gas in concrete does not only on a bigger scale reduces carbon footprint, but it also reduces the impact the construction industry has on the environment. This paper presents a detailed review on the chemical reaction that takes place during the sequestration of carbon dioxide and the research published on the effects of carbon dioxide sequestered concrete on its properties. The impact this process has on the concrete industry and the environment is discussed in this paper.

In recent years, the production of cement has grown globally in a very rapid manner due to the modernization of the world we live in, and after fossil fuels and land-use change, cement production is the third-largest source of anthropogenic emissions of carbon dioxide, CO2. Cement being the primary binding material for concrete and with the prospects for the concrete industry continues to grow so will the emissions of CO2. Hence, a method to reduce the CO2 production while keeping up with the progression of the concrete industry is very crucial in current times. This is where CO2 sequestration comes in. It is a process where CO2 is converted into a mineral which will then be trapped into the concrete forever. Required data to carry out the research between CO2 sequestered concrete and concrete without CO2 have been observed, obtained and tabulated as necessary. These data are then used to compare the concrete samples with one another and also prove the theoretical effects of CO2 exposure to concrete. Hence, experimental results on the compressive strength of the concrete samples for 7, 14 and 28 days has also been tabulated, graphed and further disputed. The objective of this research is mainly to determine the compressive strength of CO2 sequestered concrete in comparison with concrete without CO2 in order to decrease the effects the concrete industry has on the environment. The compressive strength of concrete samples with sequestration of CO2 gas is expected to be higher than of the concrete without CO2.

Fibres Reinforced Concrete has received much interest in the concrete research world over the last few decades. Assimilating fibres into concrete structures has many advantages. Previous study discovered that the addition synthetic or natural fibres to concrete enhanced the material’s thermal properties as well as its strength to some extent. Fibres, on the other hand, have an influence on the thermo-mechanical properties of concrete. The aim of this research is to see whether applying Polypropylene and Kenaf fibres to cement mortars of various compositions has any potential (0.1 %, 0.2 %, and 0.3%). Eight separate mixes were tested in this report. The addition of PP and Kenaf fibres reduced the workability of the mortar samples as measured by flow ability, compressive strength, tensile strength, and thermal conductivity. In contrast to other ratios, cement mortar containing 0.1% PP and Kenaf fibres have highest compressive strength, while samples containing 0.3% recorded highest tensile strength which are 6.2 MPa and 7.2 MPa respectively. When higher percentages of both fibres are used in mortar samples, the thermal conductivity decreases. It can be inferred that adding a certain percentage of fibre to a composite can boost both mechanical and thermal properties.

Soil requires load bearing impact assessment for stability. Therefore, this study aims to utilize the multi-channel analysis surface wave (MASW) for soil subsurface investigation and profiling around Peninsular Malaysia. The standard penetration test (SPT) was conducted for comparison between factual N-value and computed N-value from shear wave velocity (Vs ) obtained from MASW using the Imai and Tonouchi equation. The correlation coefficient (R) and coefficient of determination, (R2 ), showed strong relationship between factual N-value and computed N-value. The model of Vs and factual N-value data distribution is non-normal but the analyzed relationship shows a significant level of p-value < 0.05. The R2 for each location of Vs -N-value relationship are ranging from 0.5 to 0.9.

Perak River basin is in Perak state of Peninsular Malaysia. In this research, the river stretch serves as water intake for domestic, agricultural and industrial purposes in Perak Tengah, Hilir Perak and Manjung regions. It is located in mixed use area whilst exposing the river to anthropogenic elements. The sampling locations were conducted at selected points of Perak River namely Tanjung Belanja Bridge (TBB), Water Treatment Plant Parit (WTPP), Parit Town discharge (PTD), Water Treatment Plant Senin (WTPS) and Water Treatment Plant Kepayang (WTPK). The existence of aromatic hydrocarbons in freshwater samples was pre-assessed via qualification analysis; specific ultraviolet absorbance (SUVA254) method at 254 nm of wavelength. The SUVA dataset were 48.38 L/mg-m (TBB), 50.54 L/mg-m (WTPP), 8.05 L/mg-m (PTD), 85.75 L/mg-m (WTPS) and 217.39 L/mg-m (WTPK). The SUVA254 values of fresh water at the river basin have exceeded the water quality standards value equivalent to 2.0 L/mg-m permitted by the Environmental Protection Agency of United States. The exceeding values were an indication of a large portion of aromatic compounds in the water. Qualification analyses evident the existence of water pollutants at treacherous concentrations for public health in freshwater samples of Perak River basin. Thus, this research has presented important findings towards further research and countermeasure for a better alternative of water treatment in Malaysia.

Coal bottom ash (CBA) is a one of coal combustion by-products from the production of electricity in coal fired power plants. Although it is classified as hazardous waste and the usage of this material is very limited, it is also an alternative material that benefits the construction industry in replacing cement or fine aggregate at certain percentage. CBA contains heavy metals. The possibility of heavy metals fluxes from the concrete is of great concern as it may cause highly potential adverse environmental impacts especially if the concentration is at beyond regulated standards. This will stop the reuse of CBA in the construction industry and may lead to deficit to entities like power plants due to the high cost of CBA disposal. Thus, this paper presents an overview on the studies of heavy metals immobilization for building materials in the construction industry. Techniques applied for heavy metals immobilization during solidification and stabilization (S/S) process using alkali activation, hydration, thermal treatment and synthesis of dicalcium silicate (β-Ca2SiO4) were briefly described.

Alkali-silica reaction causes major problems in concrete structures due to the rapidity of its deformation. Factors that affect ASR include the alkali and silica content, relative humidity, temperature and porosity of the concrete, making the relationship a complex phenomenon to be understood. In investigating the mechanical deformation of the structure, the theory of continuum damage mechanics proves to be a suitable method. Damage mechanics can be used to predict the physical and chemical behavior of a structure, making it an appropriate method to study the behavior of the structure under the influence of alkali-silica reactivity. Therefore solution of the damage model is critically needed to overcome the concrete deformation problem. In this research, an engineering example of a thermo-chemo-hygro-mechanical model of a concrete gravity dam at the macroscale and coupled with the mesoscale will be studied for varying environmental conditions of temperature and relative humidity. The simulation was developed using the stochastic finite element software. Investigations found that temperature, as well as relative humidity influences the latency and characteristic time constants, which dictate the rapidity of ASR expansion into the structure, rendering heterogeneous values across the cross-section of the structure according to the relative humidity and temperature distribution.

Graphical abstract, Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic compounds, composed of two or more fused benzene rings and abundantly found in mixed-use areas. Mixed-use areas consist of dense population, urbanization, industrial and agricultural activities. River pollution are common in mixed-use areas and 98% of Malaysia's fresh water supply originates from surface water. The biological degradation, adsorption and advanced oxidation process were documented as the available PAHs treatment for water. To date, the application of the photo-Fenton oxidation process has been reported for the treatment of PAHs from contaminated soil (review paper), landfill leachate, municipal solid waste leachate, sanitary landfill leachate, aniline wastewater, ammunition wastewater and saline aqueous solutions. As for potable water, the application of Fenton reagent was aided with photo treatment or electrolysis not focusing on PAHs removal. • The presented MethodsX was conducted for PAHs degradation analysis in potable water samples using photo-Fenton oxidation process. • The designed reactor for batch experiment is presented. • The batch experiment consists of parameters like concentration of 17 USEPA-PAHs in the prepared aqueous solution (fixed variable), reaction time, pH and molarity ratio of hydrogen peroxide (H2O2): ferrous sulfate (FeSO4).

The water stream has been reported to contain non-steroidal anti-inflammatory drugs (NSAIDs), released from households and premises through discharge from Sewage Treatment Plant (STP). This research identifies commonly consumed NSAIDs namely ibuprofen (IBU), diclofenac (DIC), ketoprofen (KET) and naproxen (NAP) in the influent wastewater from two urban catchments (i.e. 2 STPs). We expand our focus to assess the efficiency of monomer (C18) and dimer (HLB) types of sorbents in the solid phase extraction method followed by gas chromatography mass spectrometry (GCMS) analysis and optimize model prediction of NSAIDs in the influent wastewater using I-Optimal design. The ecological risk assessment of the NSAIDs was evaluated. The HLB produced reliable analysis for all NSAIDs under study (STP1: 6.7 × 10−3 mg L−1 to 2.21 × 10−1 mg L−1, STP2: 1.40 × 10−4 mg L−1 to 9.72 × 10−2 mg L−1). The C18 however, selective to NAP. Based on the Pearson proximity matrices, the DICHLB can be a good indicator for IBUHLB (0.565), NAPC18 (0.721), NAPHLB (0.566), and KETHLB (0.747). The optimized model prediction for KET and NAP based on DIC are successfully validated. The risk quotients (RQ) values of NSAIDs were classified as high (RQ > 1), medium (RQ, 0.1–1) and low (RQ, 0.01–0.1) risks. The optimized models are beneficial for major NSAIDs (KET and NAP) monitoring in the influent wastewater of urban domestic area. An upgrade on the existing wastewater treatment infrastructure is recommended to counteract current water security situation.

Objective: This paper reviews the literature available on coal bottom ash (CBA) and its applications in building industry. Methods: The current trends on the reuse of CBA have been reviewed and the various properties of CBA are presented and discussed. Different percentage of CBA replacement in concrete was used. Findings: CBA were found thermally stable within the temperature range considered. Workability of fresh concrete containing CBA show a lower value due to the higher amount of replacement which required huge amount of water which effect the workability. Compressive strength of the concrete shows that it’s reached optimum strength beyond 28 days and no leachate of toxic elements in CBA was present. Application/Improvements: The review of the literature showed that the CBA was successfully recycle and applied for replacement as fine aggregate as well as coarse aggregate. It is concluded that the recycling of CBA as cement replacement material and also processing of CBA to develop nano-material are the future of CBA research. Keywords: Coal Bottom Ash, Compressive Strength, Power Plant, Sustainable Material, Workability

This paper investigates the performance of scirpus grossus (SG) fiber and fiberglass (FG) as ceiling material. Scirpus grossus was extracted by peel method. Mixture containing scripus grossus, fiberglass and carboxymethyl cellulose (CMC) was cast with thickness of 7.5 and 15 mm of both fibers namely as 7.5SG, 15SG, 7.5FG and 15FG and undergo tensile strength test, flexural strength test and water absorption test. The result show, 7.5FG has the highest water absorption compared to SG7.5 with difference of 21% whilst for ceiling with thickness of 15 mm, 15SG show the lowest value of water absorption compared to 15FG with 17% of difference. Meanwhile, flexural strength of both thicknesses was comparable for both fibers. It is concluded that, natural fiber shows a good potential to be explore as ceiling material for energy efficiency building application in future for tropical climates zones area.

Diapers are reusable waste. This research presents physicochemical properties of sodium polyacrylate in new (ND) and used (UD) diapers, via wavelength-dispersive X-ray fluorescence (WDXRF), Fourier transform infrared (FTIR), X-ray diffraction (XRD), pH, turbidity and colour. Additional constituents detected in ND, while others were slightly higher in UD. Slight decrease (2000–2500 cm−1, UD) and bulk peaks (3287–3333 cm−1, UD) were observed and functional group at 2897 cm−1 (ND) disappeared showing their role as absorption sites. The pH (6.83–8.50), turbidity (16.3–36.6 NTU) and colour (153–432 Pt.Co) values were obtained. Thus, this provides a baseline reference for diapers application in concrete technology.

Polycyclic aromatic hydrocarbons (PAHs) are mutagenic and bio-accumulates in nature. This research aims to determine the ecological and health risk assessment of PAHs in Sungai Perak, Malaysia. The sampling was conducted at the up and downstream of Sungai Perak in the district of Perak Tengah, Malaysia. The sampling stations were Tanjung Belanja Bridge (TBB), Water Treatment Plant Parit (WTPP), Parit Town Discharge (PTD), Water Treatment Plant Senin (WTPS) and Water Treatment Plant Kepayang (WTPK). The water treatment plants channel water through the distribution network, to Manjung (249,600 people), Perak Tengah (249,600 people), Kinta (810,400 people) and Hilir Perak (144,400 people) districts. The hazard quotient (HQ) and hazard index (HI) were applied for ecological and health risk assessments. The lifetime cancer risk (LCR) was employed for the health risk assessment. The PAHs contamination level presumptions for all sampling campaigns were low (0–100 μg/L). The HI values of ecological and health risk assessments were found to be aligned with each other. The HI values for raw water were below one ( 1) indicating to high risk to aquatic organisms and human health. However, the LCR for raw and treated water exceeded the maximum permissible limit, 1.0 × 10−6 equals to cancer risk of 1 in 1,000,000 people. The LCR for raw water were 1.71 × 10−4 (TBB), 1.35 × 10−4 (WTPP), 1.43 × 10−4 (PTD), 9.54 × 10−5 (WTPS) and 2.37 × 10−4 (WTPK). Meanwhile, the LCR for treated water were 6.90 × 10−5 (WTPP), 5.42 × 10−5 (WTPS) and 2.63 × 10−4 (WTPK). The conventional water treatment system appears to be inefficient to remove PAHs, risking the security of public health. Thus, restructuring the infrastructure of water treatment plants or considering an alternative to rivers as domestic water sources are highly recommended.

Coal ash (fly (FA) and bottom (BA) ashes) contain heavy metals. This research presents physicochemical and leaching properties of coal ashes (FA, BA and FA + BA) from a Malaysian power plant. The physicochemical (X-ray fluorescence (XRF) and scanning electron microscopy (SEM)) and leaching properties (toxicity characteristic leaching (TCLP) and synthetic precipitation leaching (SPLP) procedures) of ash samples were determined. Heavy metals like lead (Pb), zinc (Zn), copper (Cu) and arsenic (As) were quantified using atomic absorption spectrometer (AAS). Leaching properties were found to complied to the standard guidelines for heavy metals. Further investigation on leaching properties is recommended for construction industry applications.

Coal bottom ash (CBA) is a coal combustion by-products produced by coal-fired power plants. It is an alternative for cement material whilst reducing greenhouse effect. This research aims to investigate immobilization of heavy metal in concrete mortar contained of CBA. The solidification/stabilization (S/S) method was applied for the immobilization purpose. Chemical bonding and the functional group of the CBA mortar were comparable to the OPC cement mortar as negative control. Thus, CBA has good potential as eco-friendly cement binder for a better environment.

Most of the world’s energy production is still mainly achieved by the combustion of coal in power stations. In Malaysia, seven power plants under Tenaga Nasional Berhad Malaysia (TNB) continuously produce around 790 tons of Coal Bottom Ash (CBA) per day. These vast volumes pose a problem in the disposal of the CBA which conventionally is loaded onto ash landfills. Many of the metals and oxides contained by the CBA are environmentally hazardous. When the CBA is disposed in landfills, the metal oxides are leached out and find their way into potable water and into animal and plantations. Disposal of the unused CBA is costly and poses financial disadvantages to power station and to the environment. However, the metals contained inside the CBA may be valuable to various industry if there is a way to extract the metals out of the CBA. This study focused on investigating the extraction of iron from coal bottom ash by the carbon reduction method. The rationale for this process was that by removing and recovering these major constituent elements from the ash, it would be easier to concentrate and isolate the trace elements especially the rare earth elements that are present in the CBA. The chemical composition of the CBA is then determined by x-ray fluorescence. The main mineral phases in CBA were determined to be quartz, aluminium oxide and iron (III) oxide. The experimental results obtained from the carbon reduction method showed that the optimum time for the reduction of iron (III) oxide by carbon from CBA is 30 minutes and the optimum temperature for the reduction is 800°C.

Fly ash is a by-product of coal combustion. Coal ash is a waste that produces a large amount of fly ash generated at the Coal Fired Power Plant throughout the year. Continuous ash production consequents in expansion of ash dumps. Coal ash also poses significant health threats. Cenosphere is one of the value-added materials that is found in coal fly ash. This study is to determine the characteristic of cenosphere in terms of chemical composition, particle size distribution, amorphousness, and surface morphology. In order to extract the cenosphere from the fly ash sample, the separation method used is the Wet Separator method (Floatation/Float and Sink Method). Cenospheres have good potential as sustainable material due it’s the unique properties, where it can be used as an alternative material in many industrial applications. A better understanding of the cenosphere characteristic will have important implication for coal waste application and it will improve the development of sustainable materials application in industry.

Coal Bottom Ash (CBA) is a solid residue produced by coal-fired power plants. In Malaysia, seven power plants under Tenaga Nasional Malaysia continuously produce around 790 tons of CBA per day. Research found that CBA is composed of Ferric Oxide (Fe2O), Aluminum Oxide (Al2O), Calcium Oxide (Ca2O), and Sulphur Trioxide (SO3) in form of insoluble metal oxides. Many of these metals and their oxides are environmentally hazardous. When the CBA is disposed in landfills, the metal oxides are leached out and find their way into potable water and into animal and plantations. Disposal of the unused CBA is costly and poses financial disadvantages to power station and to the environment. However, the metals contained inside the CBA may be valuable to various industry if there is a way to extract the metals out of the CBA. By using the Acid Soluble (AS) and Ion Exchangeable (IE) methods, it was shown that Ferum could be effectively extracted by using Ion Exchangeable (IE) method compared to Acid Soluble (AS) by using citric acid.

Rice is a primary source of food for billions of people and covers 1% of the earth’s surface. On average 20% of the rice paddy is husk, giving an annual total production of 120 million tones. Nowadays, there are two common methods used to dispose the rice husk which is either it is being dump or burnt. Rice husk ash (RHA) which is produced by burning paddy husk led to the issue of ozone layer depletion. It also causes damage to the land and the surrounding area where it is being dumped. Previous studies have pointed out that RHA produced contains more than 80% pure silica and if properly prepared, it is in an active form which behaves very much like cement. Same goes with used engine oil (UEO). Many people are aware that UEO shouldn’t be dumped, but recycled. It is incredibly toxic stuff and a gallon can contaminate one million gallons of water. Pouring it on land doesn’t reduce the risk either as it can seep down into the water table.The objective of this research is to obtain an optimum percentage of inclusion of microwave incinerated rice husk ash (MIRHA) as a cement replacement and UEO in order to produce a better concrete in terms of compressive strength compared to normal OPC concrete. The test results showed MIRHA concrete performed better than normal OPC concrete and the incorporation of UEO and MIRHA in concrete showed the compressive strength give better performance.

This study investigated the influence of laminate properties toward the collapse of composite cross arm structure under multi-axial quasi-static loading. A three-dimensional finite-element model of a cross arm was developed and integrated with Hashin’s failure subroutine to predict the inter-laminar damages of the composite upon its application. The mechanical deformation and failure of the composite structure were evaluated over three laminate properties. This investigation revealed that variation in laminates properties yielded different structural deflection and laminate damages. The cross arm with a greater young modulus and ultimate stresses (laminate B) experienced a single failure mode of fiber buckling in compression at deflection of 0.082 m. For the given multi-axial load, the laminate configuration and properties considered in this study failed to prevent the failure of the cross arm.

Quality of the construction project is very crucial issue nowadays. Sometimes works are carried out in place where there is acute shortage of water and the application of water curing is not possible for reasons of economy. There are several papers studied on internal curing agent and effect to the concrete such as from Polyethylene Glycol (PEG400), ceramic and Super Absorbent Polymer that make them beneficial for engineering and construction applications. Year by year, increasing of waste from disposable diapers will give impact to dumping area. Internal curing agent that used in this research is new diapers contain of super absorbent polymer, which becomes a gel-like substance when wet and absorb the water. Diapers are primarily worn by infants, and by children who are not yet potty trained or who experience bedwetting. In this research, it will be analyzed by investigating the workability and compressive strength impact to the concrete. Design Mix with size of cube 100 x 100 x 100mm has been testing day 3, 7, 28 and 90 days with the ratio from 0% as a control and 1%, 2%, 3%, 5% and 10%. From the result that had obtained, 1% of diapers polymers can conclude that the internal curing process can help to improve the hydration process. When the hydration process occurs, the polymer can transfer the water to all part of the concrete and to the hydration point it results the early age cracking can be preventing and promotes maximization of cement hydration, potentially contributing to increase the strength and the fluid transport coefficients can be reduced.

Coal ash is the residue that is produced during coal combustion for instance fly ash, bottom ash or boiler slag which was primarily produced from the combustion of coal. With growth in coal burning power station, huge amount of coal bottom ash (CBA) considered as hazardous material which are normally disposed in an on-site disposal system without any commercialization purpose. Previous researchers have studied the extraction of silica from agricultural wastes such as palm ash and rice husk ash (RHA) and CBA by using leaching treatment method. In this study, the weaker acid, citric acid solution was used to replace the strong acid in leaching treatment process. Result showed that the heavy metal content such as Copper (Cu), Zinc (Zn) and Lead (Pb) can be decrease. Meanwhile the silica can be extracted up to 44% from coal bottom ash using citric acid leaching treatment under the optimum reaction time of 60 minutes with solution temperature of 60°C and concentration of citric acid more than 2%.

Since global warming and green buildings have been the concern of the scientific society, efforts were made toward achieving more green and sustainable buildings. One of the efforts was to utilize waste materials such as Coal Bottom Ash (CBA) as cement replacement in the concrete mixture to reduce the harmful effects of cement manufacturing procedure and dumping of coal burning products from utilities industry. This paper studies the effect of replacing cement in concrete mixture by CBA. The porosity of four different concrete mixtures including control mixture was studied using different percentages of CBA, which are 0%, 10%, 20%, and 30% as cement replacement. The results have shown improvement in porosity at 10% and 20% replacement. However, 30% replacement was chosen as the optimum percentage since it showed a 6.825% percentage of porosity which is slightly similar to control mixture, therefore, it utilize larger amount of CBA while providing normal concrete quality, which contribute to the sustainable waste management target of Malaysia.

Implementing the sustainable materials become a trend nowadays including construction industry. As cocnrete usage become next two water, a more cost effective and economic new type of green admixtures may give positive impacts on the Malaysian construction building as well as worldwide concrete usage. Therefore, this paper focuses on the effects of used cooking oil as admixture in concrete. The objectives of this research are to determine effects of UCO interms of workability, mechanical properties and microstructure. The result obtained shows that UCO give positive effects of all properties presented in this research. It increases a workability, improve mechanical properties and decrease the ITZ and air voids size compared tocontrol mix. Hence, it can be stated that UCO can possibly act as admixture towards a good quality of concrete using sustainable products.