bluuebunny/crossref_metadata_2025 huggingface dataset:
PERFORMANCE OF MIXED EXPONENTIAL AND EXPONENTIAL DISTRIBUTION REPRESENTING RAIN CELL INTENSITY IN NEYMANSCOTT RECTANGULAR PULSE (NSRP) MODEL
Authors: Yusof Fadhilah , Mohd Daud Zalina , Nguyen V-T-V Nguyen V-T-V , Yusop Zulkifli
Published: July 2024

Sub-daily timescale data such as hourly data are needed for modeling urban systems. However such series are not readily available as compared to daily rainfall series. Stochastic rainfall models are useful in estimating input for design work. One of the models that applies the clustered point process theory is the Neyman-Scott Rectangular Pulses (NSRP) model. The model uses a flexible model fitting procedure which involves matching approximately a chosen set of historical statistics which exceeds in number of set of parameters to be estimated. An optimization technique called Shuffle Complex Evolution (SCE-UA) was used to estimate the parameters. The performance of NSRP model was evaluated using 10 years hourly data taken from a station in Wilayah Persekutuan. Two distributions, namely exponential (EXP) and mixed exponential (MEXP) were used to model the cell intensities in the model. The models were evaluated on a monthly basis regarding their ability to preserve the statistical properties as well as the physical properties of the rainfall time-series over timescales of 1 h, 6 h and 24 h. The performance of the models with the two different distributions was evaluated and compared. The model with the mixed exponential (MEXP) distribution perform better in preserving most of the statistical and physical properties of the observed data
EFFECT OF FILLER ON STRENGTH DEVELOPMENT OF EPOXY GROUT
Authors: Siong Kang Lim , Hussin Mohd Warid
Published: July 2024

Epoxy grout is used for most structural repair works due to its high strength, adhesive and availability. This study uses epoxy resin and its hardener as binder, graded sand and ground granulated blast furnace slag (GGBFS) as filler to produce the epoxy grout. The objective is to produce a sufficient mix proportion for epoxy grout that has good workability and high strength properties, which can be used as structural repair material. The method used to obtain the mix proportion was by trial mix as determined by flowability and strength of the grout. Several batches of epoxy grouts with different epoxy: hardener: filler ratios were designed and tested for its flowability and compressive strength properties. Finally, the mix proportion with fresh properties, namely viscosity or flowability that fulfills the requirements of ASTM C 881 and has optimum strength development was selected. The optimum compressive strength obtained for epoxy grouts with 5:1:11 epoxy:hardener:filler ratio was above 70 MPa for air cured specimen, which can be considered as high strength repair material. The results for slag based epoxy grout showed that the replacement of slag up to 50% as filler to epoxy mix with proper mix proportion is suitable to be used in concrete structural repairs.
AN INVESTIGATION ON THE ATTENUATION CHARACTERISTICS OF DISTANT GROUND MOTIONS IN PENINSULAR MALAYSIA BY COMPARING VALUES OF RECORDED WITH ESTIMATED PGA AND PGV
Authors: Zaini Sooria Sherliza , Sawada Sumio , Adnan Azlan , Goto Hiroyuki
Published: July 2024

The development of a design motion requires some input on ground motion characteristics. For a country such as Malaysia, where historical data is lacking and seismic activities are low, the information on characteristics of ground motion may be obtained by utilizing established attenuation relationships. This study aims to investigate the characteristics of distant ground motions in Peninsular Malaysia, which originated from the active tectonic plate of Sumatra, by comparing recorded peak ground acceleration (PGA) and peak ground velocity (PGV) values with those estimated using four attenuation models. Selected attenuation models are the Atkinson and Boore (1995), the Toro et al. (1997), the Dahle et al. (1990), and the Si and Midorikawa (1999) models. The analysis for comparison was made by employing a maximum of 46 horizontal component accelerograms, recorded at 14 seismic stations. These are data derived from 15 interplate earthquakes between May 2004 and July 2007. Recorded PGA and PGV values were plotted on respective attenuation curves to examine ground motion attenuation characteristics. Results indicated that attenuation models, established for stable tectonic regions, provide good estimation of PGA and PGV for Sumatran earthquakes for magnitude range of 5.9 to 9.0. The study shows that the Dahle et al. (1990) model best represents the characteristics of ground motions in terms of PGA, while the Atkinson and Boore (1995) model gives appropriately estimate ground motions in terms of PGV
BLOCK MODEL APPROACH FOR ANALYSIS OF ROCK BENCH STABILITY IN OPEN PIT MINES
Authors: Asof Marwan , Gofar Nurly
Published: July 2024

Wedge failure analysis conventionally adopted for the design of global angle of open pit mines is not always applicable when the area consists of jointed rock benches. In this analysis, the unstable wedge is assumed intact while, in fact, the rock bench consists of an assemblage of blocks generated by the intersections of well-defined discontinuities. Block model approach adopted in Resoblok provides an alternative solution for the design and stability analysis of a rock bench. The model analyzes the stability of individual block by limit equilibrium method while the discontinuity aspect is considered statistically based on geometrical modelling of the individual fractured rock mass. This paper presents the stability analysis of five rock benches from two mining sites. The analysis shows that Resoblok model provides a good indication of the distribution, the number and the volume of unstable blocks; therefore, it is useful for the design of open pit mines. The result of this study is in good agreement with field observation.
SEISMIC RESPONSE OF REINFORCED CONCRETE FRAMES ON FLEXIBLE FOUNDATIONS SUBJECTED TO BOTH HORIZONTAL AND VERTICAL GROUND MOTIONS
Authors: Djarir Yahiaoui , Abdelkrim Kadid
Published: July 2024

This paper investigates the effect of combined horizontal and vertical accelerations on the seismic response of reinforced concrete resting on shallow foundations. Five and nine-storey buildings are considered to represent low- and medium- rise buildings. The building was assumed to be founded on shallow foundation with soil class corresponding to soft soil deposits, The soil of foundation was modeled by an equivalent massless spring coupled with a gap, located at the base of the structure, allowing for the inelastic bearing capacity of the soil and the loss of contact (uplift) of the base from the supporting soil. The accelergrams used in this investigation in the nonlinear range are the horizontal and vertical components of the New Hall earthquake. Although most building codes postulate that SSI generally decreases the force demand of buildings, and increases the deformation demand, it was found that the inclusion of the vertical ground motion with SSI, the horizontal displacement are decreased compared to the case with only the horizontal component.
OPTIMIZATION OF TIME AND COST OF BUILDING COMPONENT MAINTENANCE: A CASE-STUDY IN A FIVE STAR HOTEL
Authors: Amani Nima , Mohamed Ali Nasly , Mohammed Abdul Hakim , Abd Samat Roslida
Published: July 2024

Building component maintenance management is one of the most important issues in management of building lifecycle costs. Key to successful maintenance management is the ability to survey present condition and predict the future condition for each component and facilities present in a building. The paper presents a process to optimize maintenance cost and time of caste iron pipe component in wastewater plumbing system of hotel building in Iran as a case study using the condition index (CI) method. The research uses a systematic assessment field as followed by the USACERL condition index method. To achieve this objective, cast iron pipe within wastewater plumbing system is surveyed using the economical tools for implementation of optimal maintenance time and cost based on highest saving to investment ratio. The research presents a financial analysis using the existing data. The data was collected through financial and technical sheet. Data is analyzed using the economical tools and financial analysis is simulated with simulation software. The purpose of this paper is to develop a financial analysis simulation for component maintenance assessment during its service life based on highest interest rate. The analysis results in to identify optimum maintenance time basing on the limited cost. This method helps to facilities managers and engineers to make better decisions for reducing maintenance costs and increasing the componentâ€™s service life.
FRESH AND HARDENED PROPERTIES OF CONCRETE CONTAINING STEEL FIBRE FROM RECYCLED TIRE
Authors: A.S.M. Abdul Awal A.S.M. Abdul Awal , Lion Yee Lim , Hossain M. Zakaria
Published: July 2024

This paper presents some results and discusses the feasibility of adding recycled steel fibre from scrap tires as reinforcement in concrete. A number of tests were conducted to investigate fresh and hardened state properties like slump, Vebe time, ultrasonic pulse velocity, compressive, tensile and flexural strength of recycled steel fibre reinforced concrete (RSFRC). The effect of incorporation of recycled steel fibre on various aspect ratios (l/d) of 45, 67 and 89, and volume fraction (Vf) of 0.5,1, 1.5 and 2% were experimentally investigated. Test specimens comprising of cube, cylinder and prism were prepared and tested after 1, 7 and 28 days of water curing. It has been found that the workability of RSFRC, in general, was reduced as the volume fraction of the fibre increased. The compressive strength and splitting tensile strength of RSFRC reached a maximum at l/d ratio of 67. In terms of volume, the compressive strength of RSFRC was not significantly increased by incorporation of recycled steel fibre. However, the tensile and flexural strength of RSFRC was remarkably improved with the increase of fibre content. The results obtained and the observation made in this study suggests that recycled steel from waste tires can successfully be used as fibre reinforcing material in concrete.
IMPORTANCE OF FLOW VALUES IN QUALITATIVE EVALUATION OF CARBON NANOTUBE REINFORCED CEMENTITIOUS MATRIX
Authors: Manzur Tanvir , Yazdani Nur
Published: July 2024

In the field of nanotechnology, Carbon nanotube (CNT) has the prime focus as one of the most important areas of research. A major difficulty of producing CNT-cement composites is the attainment of uniform dispersion of CNT. CNT has a tendency to agglomerate creating zones of weakness in composite materials. In this study, a parametric study was carried on surface treated multiwalled carbon nanotubes (MWNT) reinforced cementitious composites having different mix proportions and an attempt was made to establish a relation between compressive strengths and flow values of composites samples. It was observed that the effect of flow values on compressive strength was most pronounced at 28 day. Composites made with surfactant exhibited less fluctuation in flow values and corresponding compressive strengths. A higher flow value of MWNT added composites, having same mix proportion, represents more uniform distribution of MWNT within the cement grains and more stable mix. Furthermore, less variation in flow values represents more stable dispersion technique to distribute CNT within cement matrix.
COMMON ISSUES IN POST-DISASTER RECONSTRUCTION
Authors: Farahdilla Cut Elisa , Mansur Shaiful Amri , Abdullah Arham
Published: July 2024

This paper examines the types, degrees and effects of disaster, presents the phases in post-disaster response, and describes the issues arisen during post-disaster reconstruction phase. Disasters considered in this paper are only the ones that had caused great loss in terms of human lives and facilities. These conditions require well-coordinated works in the reconstruction process. There are many issues arise in the reconstruction process, ranging from operational, personnel, ethical, and funding issues. The main purpose of the paper is to identify the problems commonly occurred in the post-disaster reconstruction for various types of disaster. This study is carried out as a basis or as an initial step to develop a framework, method, and technologies to improve efficiency and effectiveness of post-disaster project. The method of this study comprises literature review from other researches in post-disaster reconstruction.
RISK FACTOR IDENTIFICATION IN THE MANUFACTURING PROCESS OF HOLLOW CORE SLAB
Authors: Herni Setiawan Theresita , Sukarni Ihzarmurafi Huza
Published: July 2024

Risk management is an effort that needs to be done by a company to manage potential opportunities and adverse impact. Risk management activities are designed to assist the practitioner in identifying significant risks and implement follow-up and risk management process. The purpose of this research is to identify the risk factors related to the activities in the manufacturing process of Hollow Core Slab (HCS) by utilizing interview method and field observation method. This is then followed by grouping those factors based on the related aspects in Project Management Book of Knowledge (PMBoK). Based on the research analysis, there are twenty nine risk factors in the manufacturing process of HCS, which then grouped on the project management aspects of PMBoK, which three risk factors to the aspects of time, five risk factors to the aspects of procurement, seven risk factors to the aspects of quality, six risk factors to the aspects of equipment resources, and eight risk factors to the aspects of human resources
INFLUENCE OF CLAY FRACTION ON VISCOSITY IN RELATION TO MUDFLOW
Authors: Widjaja Budijanto , Heng Lee Shannon Hsien
Published: July 2024

Mudflow is one type of natural disaster. This type of mass movement can be triggered by changing of water content due to increasing of rainfall intensity. The occurrence in Indonesia and Taiwan is relatively high. According to its definition, the material is dominant by fine grained soil. The viscosity as one of main rheology parameters governs mudflow movement. In order to overcome the conventional viscometer which could not measure around liquid limit, the authors developed a new laboratory test so called the flow box test (FBT). The governing equation is a couple of Terzaghiâ€™s trap door and Bingham model. From this test, one of the merit is this test can measure the viscosity around liquid limit. Using the case study in Indonesia (Ciwidey and Karangayar) and Taiwan (Maokong), the result shows that increasing of clay fraction is followed by increasing of viscosity. Hence, this research has a contribution to explain the influence of clay fraction on viscosity in relation to mudflow.
CHARACTERIZATION AND MECHANICAL PROPERTIES OF CONCRETE MIXTURES MADE WITH SEDIMENTARY LIME AND INDUSTRIAL INCINERATOR ASH
Authors: Ravasan Farshad Maleki
Published: July 2024

This paper is a review of the research work done in order to promote industrial waste into concrete for common use in building construction, with the aim of emphasizing the feasibility of use incinerator ash (IA) as fine aggregate replacement and sedimentary lime (SL) as normal cement substantial have been investigated and compared with control samples. IA were used to replace 5%, 10%,15% up to 80% of the total mineral fine aggregateâ€™s volume and SL was used to replace 10%, 15% up to 50% of the total normal cement volume in concrete. The mixtures tests included compressive strength, tensile strength, modulus of elasticity, chloride penetration and drying shrinkage. The fresh concrete mixtures exhibited lower unit weight and acceptable workability compared to plain concrete. It was found that at the age of 28 days, the compressive strengths of concrete mixtures to decrease below the plain mixtures. In F50L25 mixtures a good mechanical properties were achieved after 28 days of curing. Given the experimental data show new possibilities for this waste materials reuse as structural concrete and give great advantages in waste minimization as well as resources conservation and reduce the cost of materials.
RECYCLE TIRE ISOLATOR AS EARTHQUAKE RESISTANCE SYSTEM FOR LOW RISE BUILDINGS
Authors: Yun Tong Siow , Kasa Anuar , Osman Siti Aminah
Published: July 2024

The purpose of this research is to study the use of Recycle Tire Isolator (RTI) as earthquake resistance system to protect low rise buildings from life threatening collapses and casualties when earthquake takes place. Many buildings are built with seismic design based on the concept of increasing the resistance capacity of the structures by using shear walls, braced frames and others. However, these methods result in high floor accelerations and could cause significant damage to nonstructural components of the buildings. Some of these buildingsâ€™ content are quite costly. Hospitals and government offices, for example, are important premises which contain valuable machines or documents such as X-rays machines and the data stored in computers. RTI could be installed at the pad foundation to absorb low to moderate earthquake energy which is less than 6 Richter scale. The isolator uses recycle tire as main component to absorb lateral forces produced during earthquake. The use of RTI also helps to reduce the hazard of dumping old tires on earth. This study focuses on the role of RTI in protecting two stories buildings. The displacement of RTI was measured when vertical or lateral forces were applied. Compression test using Universal Testing Machine was carried out in the laboratory to find the maximum vertical load. The vertical load was applied to the specimen by the vertical hydraulic actuator in displacement control. The specimen was monotonically loaded to failure. COMSOL Multiphysic V4.2, a finite element software was used to model the behavior of RTI and the results were compared to the results obtained from laboratory. The behavior of RTI was also compared to the behavior of existing rubber bearing (RB) and scrap tire pads (STP). The results of laboratory and finite element analysis indicated that RTI could support a maximum axial load of 184 kN and lateral force up to 20 kN. Based on the results, RTI had a potential to be used as a device to protect low rise buildings against low to medium earthquake. The compressive strength of RTI and STP was quite similar with about 6.7% difference. This was expected since both materials were recycle tires. The compression modulus between RB and RTI was also similar with about 11.1% difference. This showed that RTI had similar features with RB and STP. However, RTI fabricated mainly by using recycle tires contained about 4 to 6 layers of steel mesh which was stiffer than RB and more efficient in supporting heavier structures vertically. The use of recycle tires in production of RTI made it more affordable for most house owners compared to RB or STP.
LABORATORY INVESTIGATION ON AN GIANG SOIL MIXED WITH DRY CEMENT
Authors: Tran-Nguyen Hoang-Hung , Kitazume Masaki , T. Luong Bich , T. Bui Tuyet
Published: July 2024

The soil-cement mixing technology is a technique mixing the in-situ soil with cement to create a new material, soil-cement or soilcrete, having better engineering properties than those of the in-situ soil such as higher strength and higher stiffness. This study investigates laboratory behaviors of local soil mixing with dry cement that will be used to construct rural road pavement for light weigh trucks (<= 2.5 tons) in An Giang province. More than 200 soil cement mixing samples were made with various cement contents at different water contents and cured at different durations. The results indicate that local fine sand with a cement content of 10% or higher can improve significantly the compression strength and secant modulus of the in-situ soil at least 15 and 50 times at 21 curing days, respectively. Therefore, a 0.5-m sand mixed with 10% to 12.5% cement can create a pavement that allows light trucks traveling safely.
RUNWAY AND HIGHWAY GEOMETRIC DESIGN WITH CONSIDERATION OF HYDROPLANING RISK
Authors: Bagui Swapan Kumar , Das Atasi
Published: July 2024

Runway is multilane high speed corridor. Width of runway varies from 23 m to 60 m. An important aspect of runway and highway geometric design is ensuring prompt removal of water from the runway / highway to reduce skidding and hydroplaning risks of aircraft /highway traffic operating under wet-weather conditions. A methodology for runway and highway geometric design that incorporates hydroplaning consideration has been proposed to ensure safe operations. Cross-slope is the main geometric element affected by the hydroplaning consideration. This paper presents an independent simplified methodology for risk calculation against hydroplaning. This methodology determines whether a trial geometric design catering to the aircraft traffic and highway traffic meets the safety requirement against hydroplaning for the selected design rainfall. Critical texture depth has been found to be 0.5mm for airport pavement to avoid hydroplaning. Provision of side slope on one side is safer than that on both sides with regard to hydroplaning risk. Hydroplaning risk increases with increasing cross-slope of the runway for a known texture depth. Hydroplaning risk in highway is minimal and risk may be minimized by limiting vehicle speed to 40 kmph or lesser during raining
EFFLORESCENCE MITIGATION BY POZZOLANIC INDUSTRIAL BY-PRODUCTS
Authors: Mohamed Sutan Norsuzailina , Hamdan Sinin , Yakub Ibrahim , Talib Zainal Abidin
Published: July 2024

This study focuses on the effectiveness of pozzolanic industrial by-products namely Fly Ash Class F (FA) and Silica Fume (SF) as partial cement replacements in reducing efflorescence on the surface of Ordinary Portland Cement (OPC) mortar. The early hydration behaviour of Pozzolanic Modified Mortar (PMM) that hypothetically affects efflorescence has been investigated physically using Puddle Test (PT), Standard Chemical Method (SCM), and Electrical Conductivity Test (ECT); mechanically using Compressive Strength Test (CS); and morphologically using Scanning Electron Microscopy (SEM). FA and SF of 10%, 20% and 30% cement replacements as PMM and Unmodified Cement Mortar (UCM) samples were prepared with water-to-cement ratio (w/c) of 0.4. All samples were cured in the concrete laboratory at daily room temperature (T) and relative humidity (RH) in the range of 18-28oC and 65-90%, respectively. Results showed 10%SF reduced efflorescence up to 52.9% in comparison to UCM. The decreased in ECT and the 12.64% increased strength evidently substantiated the EI results. Based on this study, more than 30% cement replacement is detrimental for efflorescence mitigation. It might be due to the lack of water content to initiate pozzolanic reaction because of the agglomeration of fine SF particles.
NONLINEAR ANALYSIS OF CONCRETE DEEP BEAM REINFORCED WITH GFRP BARS USING FINITE ELEMENT METHOD
Authors: M. Metwally Ibrahim
Published: July 2024

The efficient use of FRP reinforcement in deep members has been hindered due to a lack of knowledge on the behavior of such members. Till now, most of researches have mainly focused on the flexural or shear behavior of shallow members longitudinally reinforced with FRP and most of them testing at small scales. This paper presents numerical investigation of twelve large-scale concrete deep beams internally reinforced with GFRP bars without web reinforcement failed in shear which were experimentally tested and collected from literature. The collected specimens cover several parameters which usually influenced on strength and behavior of deep beams as shear span / depth ratio, the reinforcement ratio, the effective depth, and the concrete strength. Concrete deep beams are generally analyzed using conventional methods such as empirical equations or strut and tie models. These methods however do not take into account the redistribution of forces resulting from non-linear materialsâ€™ behaviors. To address this issue, nonlinear finite element analysis that incorporates non-linear material behavior as ABAQUS package will be used. It was found completely efficient in handling such analysis and the proposed simulation of the material in the present study are capable of predicting the real behavior of reinforced concrete deep beam reinforced with GFRP bars in terms of load-deflection behavior, failure load, failure mode, crack propagation, GFRP reinforcement strain, and concrete strain distribution similar to the tested large scale deep beams. Besides, deep beam reinforced with GFRP bars showed different behavior than that of beam reinforced with CFRP bars due to the low elastic modulus of GFRP bars, which was increased dramatically the deflection. Thus, the deflection, instead of strength will govern the design for concrete deep beam reinforced with FRP bars.
CURRENT WASTE GENERATION OF E-WASTE AND CHALLENGES IN DEVELOPING COUNTRIES: AN OVERVIEW
Authors: Supian Nur Sumaiyyah , Shah Gautam Lalit , Mohd Yusof Mohd Badruddin
Published: July 2024

The rapid growth of information and telecommunication technology ((ICT) in many developing countries has led to the improvement in the capacity of computers but simultaneously decrease the product lifespan which contribute to increase amount of e-waste. This paper reviews management issues related to electric and electronic waste (e-waste) as well as challenges faced by developing countries particularly China, India, Jordan, Tanzania, Philippines, Korea, Thailand, Brazil and Malaysia. Amongst the issues include awareness of institution and government, overall management and financing problem. From the review in selected developing countries, it can be concluded that the awareness of public towards e-waste management is low. Most consumers were not aware of the proper way to treat e-waste and for government and institution commitments were low as strict and consistent enforcement were lacking. Informal sector plays a major role while low-cost machinery and manual segregation was prominent. Systematic policy and regulation of e-waste management in developing countries needs to be enhanced to achieve best practices in e-waste management. Lack of financial support further exacerbated the challenges in these developing countries, as proper treatment requires a high capital and maintenance costs.
CHARACTERIZATION OF PALM OIL MILL SECONDARY EFFLUENT (POMSE).
Authors: Ahmad Shahrifun Nurul Shairah , Abâ€™lah Norul Nazilah , Hussain Hazilia , Aris Azmi , Omar Qistina , Ahmad Norlaily
Published: July 2024

This paper reports on the characteristics of the Palm Oil Mill Secondary Effluent (POMSE) in four different period of sampling. The aim of this study was to measure the value of the Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD5), color, total suspended solid (TSS), turbidity, iron ferrous, and total iron in POMSE. These basic parameters are crucial in determining a suitable treatment system to be acted on the wastewater so that the optimum condition of the treatment could be obtained. Results obtained in this study indicated that BOD5 concentration lies between 249 to 267mg/L; COD reading were between 3234 to 3624mg/L; Color were between 3860 to 5350ADMI ; total iron were between 0.24 to 1.75mg/L; ferrous iron were 1.75mg/L; TSS were between 1635 to 1875 and turbidity, 2865 to 2894NTU. Results suggest that aerobic and anaerobic treatment were not sufficient in reaching the standard discharged limit set by Department of Environment (DOE) Malaysia.
LIFE CYCLE OPTIMIZATION OF A LIGHTWEIGHT STEEL BUILDING: EFFECT OF DIFFERENT INSULATING LAYERS, GLAZING TYPE AND WINDOW SHADING
Authors: Ahmed Bhuiyan Md Refat
Published: July 2024

In recent years, life cycle assessment has become an important tool for determining the environmental impact of materials and products. It is also useful in analysing the impact of a building structure has over the course of its life cycle which includes production of materials, transport, construction, operation, end of life. This paper is intended to provide a life cycle analysis of a building located in Coimbra, Portugal. To achieve the effect of different insulation layers, glazing type and window shading, two different solutions were analysed. In order to compute the thermal transmittance U-values for the walls and roofs, Therm5 software was used, so as to account for the effect of thermal bridges induced by the steel framework. These values were then introduced in the building model, which was designed in the software DesignBuilder, in order to compute the thermal behaviour of the building. Finally, the values of the energy consumption for a period of 50 years were introduced in the life cycle analysis made in the GaBi software. This allowed estimating the impact of both solutions and providing conclusions as to which is the best solution.
EFFECT OF PARTIAL REPLACEMENT OF AGGREGATES BY RECYCLED CONCRETE DEBRIS ON STRENGTH OF CONCRETE
Authors: S. Muthu Lakshmi S. Muthu Lakshmi , R. R. Nivedhitha R. R. Nivedhitha
Published: July 2024

Lot of construction debris are generated during the construction and demolition of any concrete structure like buildings, roads, bridges etc. and sometimes, even from catastrophes like wars and earthquakes. Discarding these wastes is a very serious problem because it requires huge space for its disposal and very little demolished waste is recycled or reused. This debris after recycling can be used as aggregates in fresh concrete in order to protect natural resources and to reduce the space required for the landfill disposal thus minimising environmental pollution. In recent times, scarcity of river sand is also another major problem faced by the construction sector in India. In this paper, experimental investigations have been carried out to gauge the effect of partial replacement of natural coarse aggregates (NCA) and natural fine aggregates (NFA) by recycled coarse aggregates (RCA) and recycled fine aggregates (RFA) on compressive strength, tensile strength and flexural strength of recycled concrete. 10%, 20%, 30% of NCA and NFA were replaced with RCA and RFA respectively & the results obtained from compressive strength test, split tensile test and flexural test were compared with the conventional concrete. From the experimental study, it was observed that compressive strength & tensile strength of concrete with recycled aggregates increased up to 20% replacement of natural aggregates with recycled aggregates whereas the flexural strength of recycled concrete was found to decrease with increase in percentage of RCA & RFA. In this paper, feasibility of utilizing concrete debris after recycling in the construction industry from strength point of view has been studied.
INTERRELATION AMONG PERTINENT ELEMENTS OF CRITICAL THINKING AND MATHEMATICAL THINKING IN THE REAL-WORLD PRACTICE OF CIVIL ENGINEERING
Authors: Osman Sharifah , Abu Salleh , Mohammad Shahrin , Mokhtar Mahani
Published: July 2024

Engaging critical thinking and mathematical thinking in solving engineering problems is complying ABET engineering criteria. Thus, the understanding of interaction between these two thinking is critical for the current engineering education. However, the interaction is not thoroughly being studied in the real-world engineering practice. This paper describes the selection process of the pertinent elements of critical thinking and mathematical thinking and the interrelation among the elements in the real-world civil engineering practice, using modified grounded theory analysis. Data consisted of semi-structured interviews with eight practicing civil engineers from two consultancy firms. A total of fifty three pertinent elements emerged during open coding process. Axial coding process developed the interrelation among the pertinent elements. The findings showed that during design process, the elements were interwoven, concurrently used, indispensable and inexorably linked. Thus, the results provide main source of information to explain the interaction among pertinent elements in selective coding process.
COMPARISON BETWEEN THE VIBRATION PERFORMANCE OF LVLCONCRETE COMPOSITE (LCC) FLOORING SYSTEM MADE OF MALAYSIAN AND NEW ZEALAND LVL
Authors: Fong Lee Yen , Abd. Ghafar Nor Hayati , Abd Rahman Norashidah , Fragiacomo Massimo , Ibrahim Zainah , Buchanan Andrew
Published: July 2024

Laminated Veneer Lumber (LVL) was categorized in engineered wood which it can be produced in billets up to 18 m long and 1.2 m wide. LVL is a high stiffness material, almost three times the strength of sawn timber. It is also more reliable and with a higher modulus of elasticity. However, modern technologies led to longer span flooring system, the higher flexibility of the LVL may be susceptible to vibrations of the system. This paper investigates the vibration performance of long span LVL-concrete composite (LCC) flooring system. LCC is a hybrid system made of a concrete slab and a LVL joist, with shear connectors to prevent slip. LVL is extensively used in Australasia as main structure for timber buildings, but not in Malaysia. The LCC was modelled with the finite element software package SAP 2000 v.15 to determine the natural frequency and mode shapes of the specimens. The properties of LVL Malaysian were obtained from mechanical testing and both properties from Malaysia and New Zealand were implemented in the Finite Element (FE) model to compare their vibration performance respectively. Since the flooring system was designed as a lower resonance frequency floor, the results show that the natural frequencies of the modeling are more than 8 Hz. The vibration performances of the floors with New Zealand and Malaysian LVL were found to be greatly similar, with natural frequency of about 9 Hz to 10Hz for 8 m span length respectively.
THE PREDILECTION OF WATER AND GENERIC FILTER AS A MEDIUM FOR URBAN BUILD-UP SAMPLING
Authors: Yakubu Mahadi Lawan , Yusop Zulkifli
Published: July 2024

Sediment health risk assessment is the principal yardstick of measuring urban pollution. Direct measurement of available sediment in the environment is not common; often an indirect method is employed for the collection of a representative sample at a small scale, which could be scale up to a catchment scale for practical purposes. Therefore, the right choice of a reliable collection equipment and technique that will ensure dependable sample representation is vital in an urban pollution appraisal. The choice of unreliable buildup sampling will have a profound impact on the physicochemical, chemical and bioaccumulation investigations, which could result in flawed conclusion with catastrophic consequences. This study evaluated the weighted advantages of using water as a filter medium on one hand, and the traditional generic filter system on the other for urban dry weather buildup sampling. To ensure objective evaluation, both systems were weighted for bias, comparability, and representativeness. The water-filter recovery efficiency on common particle sizes found in urban roads shows a superior retention efficiency of 99% at particle sizes larger than 2360Âµm and an overall average of 96%. The major losses were recorded on particle sizes of 1180Âµm and those lower than 75Âµm. In all particles sizes range, the entrapment efficiency of the water-filter medium system is higher than regenerative-air sediment collectors, but is comparative with an industrial generic filter system.
INTERACTION BETWEEN COLD-FORMED STEEL AND LIGHTWEIGHT FOAMED CONCRETE WITH VARIOUS CEMENT CONTENT
Authors: Siang Tan Cher , Ling Lee Yee , Mohammad Shahrin , Kang Lim Siong , Huei Lee Yeong
Published: July 2024

The bonding strength to hold lap slice between concrete and its reinforcing steel is the essential requirement of reinforced concrete and steel-concrete composite structures. In this paper, the compressive strength of lightweight foamed concrete with designated density at 1500 Â±50 kg/m3 , by various cement-sand ratio and their respective interaction with cold-formed steel are investigated experimentally. The consistency and stability of lightweight foamed concrete are also examined towards the use of bulk sand. The results show that the compressive strength of lightweight foamed concrete increases with the increment of the cement content. For bonding strength between lightweight foamed concrete and cold-formed steel, specimens with holes in cold-formed steel sheets acting as shear connector exhibit higher pull-out strength. Moreover, the pull-out strength increases in-line with the increment of compressive strength of the lightweight foamed concrete. From the obtained results, lightweight foamed concrete with 5:1 cement-sand ratio exhibits highest compressive strength of 9.387 MPa and pull-out strength of 1.025 MPa with cold-formed steel, where holes exist as shear connector.
PERFORMANCE OF AERATED CONCRETE INCORPORATING BYPRODUCT FROM AGRO-INDUSTRY IN SULPHURIC ACID
Authors: Mehmannavaz Taha , Ismail Mohammad , P. Forouzani P. Forouzani , I.O. Hassan I.O. Hassan , Sajjadi Seyed Mahdi , Samadi Mostafa
Published: July 2024

The challenge of utilisation of sustainable, durable and cost effective building materials leads civil engineering researcher in rich agro-industrial country such as Malaysia to find suitable building materials alternatives. This paper illustrates the aspect of sustainability of cellular lightweight concrete composed of POFA and PFA at the percentage of 30% and 20% respectively when exposed to sulphuric acid for duarability test.The mix of POFA and PFA used on weight replacement of cement and concrete OPC perforemance considered as a control sample taken in this research. All samples were subjected to the curing in water for 28 days before the immersion in sulphuric acid having with a pH value of 1 to 2160 hours. The progressive deterioration was evaluated by the change in mass of the samples and visual inspection decisions regarding the compressive strength. The study showed that 30% POFA and 20% PFA improves the strength of aerated concrete attack by sulphuric acid.
COMPARISON OF AUTOMATIC CALIBRATION TECHNIQUES FOR SIMULATING STREAMFLOW IN TROPICAL CATCHMENT
Authors: Hadipour Sahar , Harun Sobri , Shahid Shamsuddin
Published: July 2024

Efficacy of hydrological model strongly depends on model calibration. A number of methods has been developed and employed for optimization of hydrological model so that model can replicate the observed streamflow accurately. A study has been carried out in this paper to find the best parameter optimization method for the calibration of a daily rainfall-runoff model for streamflow simulation of a tropical catchment. For the purpose, seven well known parameter optimization methods namely, Uniform Random Search, Pattern Search, Multi Start Pattern Search, Rosenbrock Method, Multi Start Rosenbrock Search, Genetic Algorithm and Suffled Complex Evaluation are used for the calibration of a conceptual hydrological model known as SIMHYD. Performance of the methods is evaluated by using Nash-Sutcliff coefficient and correlation coefficient. The result indicates that evolutionary algorithm based optimization techniques can optimize the model parameters more accurately for precise calibration of model and reliable prediction of daily streamflow in a tropical catchment.
BOND PERFORMANCES BETWEEN CFRP PLATE AND STEEL PLATE TO CONCRETE PRISM USING STRUCTURAL ADHESIVES
Authors: Mokhtar Nor Izzah , Abu Hassan Shukur , Mohd. Sam Abdul Rahman , Ahmad Yusof , Omar Balqis
Published: July 2024

Repair and rehabilitation of existing structures is a necessity compared to impractical application by direct replacement of the structures. Repair using steel plates to concrete structures had been seen as the most popular method but these techniques had drawn many problems at sites. Recent application of repair and rehabilitation involved externally bonded reinforcement that causing interface performance as an interesting area to be studied. Performance of epoxied system in externally bonded plates needs to examine more to improve database in literature. This study is required to discover the behaviour of interfacial bond in epoxied based. Bonding of external plate to concrete surfaces using adhesive is a practical solution for upgrading the existing reinforced concrete structures. This paper focuses on the bonding performance of epoxy resin adhesives to CFRP-concrete and steel-concrete prisms. Concrete prisms size of 100 Ã— 100 Ã— 300 mm with roughened surface on both sides was prepared. Surface preparation of the concrete prisms was carefully made prior to bonding to CFRP plates and steel plates respectively. Two groups of specimens, namely CFRP Plate-Epoxy-Concrete Prism and Steel Plate-Epoxy-Concrete Prism, were prepared and tested by applying direct tensile loads until failure. The strain distribution along the bond length of the CFRP Plate-Epoxy-Concrete Prism was fairly linear but with further increase of loads, the local strain became non-uniform and non-linear. The strain distribution along the bond length for Steel Plate-Epoxy-Concrete Prism was almost linear, i.e. proportional to the applied load and uniform. The specimen did not failed at the bonding region but failed due to yielding of steel plates. Result from direct tensile test of the steel plates had drawn to conclusion that the strength of steel plates used for this study was not sufficient in term of strength. The test results showed that structural type of epoxide resin was suitable to be used as structural adhesive. The bonding strength was affected by the length of the bonding surface, modulus of elasticity of the materials and interfacial conditions. It is proven by the better performance from CFRP-prism samples with 283.2MPa local bond stress maximum differences if compared with the Steel-prism. Stress concentration was quite close at bond length of 15mm to 35mm. The stresses decreased gradually from bond length of 65mm to 155mm. The longer or wider the bonding surface, the stronger the bonding strength would be but had to be limited to effective bond length of 60 mm to 120 mm of bond length.
FRESH AND HARDENED PROPERTIES OF SELF-COMPACTING LIGHTWEIGHT CONCRETE USING COARSE PALM OIL CLINKER
Authors: Feen Owi Siew , Mohamed Roslli Noor , Mohamed Azman
Published: July 2024

The utilisation of industrial waste from the palm oil industry offers benefit to the construction industry and environment. This paper presents the experimental investigation of the fresh and hardened properties of self-compacting lightweight concrete (SCLWC) using coarse palm oil clinker (POC). In this study, POC, a waste by-product of palm oil mill, was utilised at 100 % full replacement of coarse aggregates in the production of self-compacting concrete (SCC). Fresh properties of the concrete mix were determined through tests of slump flow, V-funnel, J-ring, L box and sieve segregation. Meanwhile, the hardened concrete properties were evaluated by means of density, ultrasonic pulse velocity (UPV), compression, tensile splitting and flexural tests. The fresh and hardened properties of SCLWC were compared to normal SCC using normal weight coarse aggregates. Test results indicated that the SCLWC exhibited accepted self-compacting characteristics as recommended by European Guidelines. The SCLWC can be classified as lightweight concrete since its hardened density at 28 days was 1985 kg/m3 and good in quality according to its UPV values. In addition, the substitution of POC reduced the compressive and tensile strengths of the concrete due to its lightweight and porous nature. Based on the performance of SCLWC utilising coarse POC aggregates, the POC is potentially viable to replace natural aggregates and suitable to be used in SCLWC.
NUMERICAL STUDY OF TURBULENT FLOW FOR MODERATE-SLOPE STEPPED SPILLWAYS
Authors: Chakib Bentalha
Published: July 2024

Stepped spillway is a power full hydraulic structure for energy dissipation because ofthe large value of the surface roughness. The performance of the stepped spillway is enhancedwith the presence of air that can prevent or reduce the cavitation damage. This work aims tosimulate air entrainment and determine the characteristics of flow at stepped spillways. Withinthis work flow over stepped chute is simulated by using fluent computational fluid dynamics(CFD). The volume of fluid (VOF) model is used as a tool to simulate air-water interaction onthe free surface thereby the turbulence closure is derived in the k âˆ’Îµ turbulence standard model.The found numerical results agree well with experimental results.
EFFECTS OF SNAIL SHELL ASH ON LIME STABILIZED LATERITIC SOIL
Authors: Nnochiri Emeka Segun , Ogundipe Olumide Moses , Emeka Helen Oluyemisi
Published: July 2024

As a result of increase in population and socioeconomic activities, the rate of production of wastes over the years has been on the rise. A major approach towards managing these wastes is to consider the possibility of waste recycle and minimization. This study assesses the effects of Snail Shell Ash (SSA), a product of snail shell-which itself is a waste product, on lime stabilized lateritic soil. Preliminary tests such as; specific gravity, Atterberg limits and particle size distribution tests were carried out on natural soil sample, for the purposes of identification and classification. The soil sample based on AASHTO classification was classified as A-7-5. Hydrated lime was added to the soil sample at varying proportions of 2, 4, 6, 8 and 10% by weight of soil, thereafter, each of the mixes was subjected to Atterberg limits tests to get the optimal amount of lime required, which was 10% lime because it was at this amount of lime that the least value of plasticity index was gotten. The Snail Shell Ash was later added to the lime-treated lateritic soil at proportions of 2, 4, 6, 8 and 10%. Each of the mixes was subjected to compaction, California bearing ratio (CBR), Atterberg limits and unconfined compressive strength (UCS) tests. Results from these tests showed improvement in soil properties, also, the values of the CBR and UCS increased considerably. At soil natural states, CBR values of 9.5% and 5.5% increased to 67.20% and 53.60% at 6% SSA at unsoaked and soaked states respectively. Also, UCS value of 190 kN/m2 at soil natural increased to 380kN/m2 at 6% SSA. It can be concluded that the SSA performs satisfactorily as a cheap complement for lime in stabilizing lateritic soil.
PHYSICAL AND MECHANICAL PROPERTIES OF CEMENT MORTAR USING LIME AND BAMBOO-ASH AS PARTIAL REPLACEMENTS
Authors: David Nkumah Lucky , Hassan Lasisi Kayode
Published: July 2024

The effect of varying different proportion of bamboo ash and lime as partial replacement for cement in mortar were studied. Bamboo stalks were collected and burned into bamboo ash in furnace. The results of the physical and mechanical properties of the cement and aggregate used were within the requirements stipulated by relevant standards. The mix proportion 1:6 was used out of which 2%, 4% of bamboo ash and 2%, 4% of lime were used to partially replace cement in the mortar. The compressive strength of most of the mortar cubes increases with curing days and their values lie within the required strength of 2.5 N/mm2 â€“ 6.5 N/mm2 as stipulated by relevant codes. The water absorption rate was observed to increase with increase in bamboo ash and lime content, while the density decreases as the percentage of bamboo ash and lime in the mortar increases by mass. The study therefore can be concluded that in the presence of significant proportion (i.e. 4% or more) of bamboo ash the strength of mortar increased hence making it adequate for the production of masonry mortar and reduces building failure.