Civil Engineering Dimension (E-Journal)
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Study on Reactivity of Circulating Fluidized Bed Combustion Fly Ashes in the Presence of Water
Get PDFA study on reactivity of four different Circulating Fluidized Bed Combustion (CFBC) fly ashes has been realized in the presence of water. Paste of each ash was prepared and analyzed for its setting time, expansion and strength. The products of hydration, and their evolutions over a period of time were identified by X-ray diffraction and differential thermal analysis. The results of this study show that the reactivity of the CFBC fly ashes is strongly related to their chemical composition, essentially to their quantity of silica, alumina, lime and sulfate, which promote principally the formation of ettringite, gypsum and C-S-H. It is further noted that the intensity and the proportion of these phases determine the hydration behavior of the CFBC fly ashes
Compressive Strength of Volcanic Ash/Ordinary Portland Cement Laterized Concrete
Get PDFThis study investigates the effect of partial replacement of cement with volcanic ash (VA) on the compressive strength of laterized concrete. A total of 192 cubes of 150mm dimensions were cast and cured in water for 7, 14, 21, and 28 days of hydration with cement replacement by VA and sand replacement by laterite both ranging from 0 to 30% respectively, while a control mix of 28-day target strength of 25 N/mm2 was adopted. The results show that the density and compressive strength of concrete decreased with increase in volcanic ash content. The 28-day, density dropped from 2390 kg/m3 to 2285 kg/m3 (i.e. 4.4% loss) and the compressive strength from 25.08 N/mm2 to 17.98 N/mm2 (i.e. 28% loss) for 0-30% variation of VA content with no laterite introduced. The compressive strength also decreased with increase in laterite content; the strength of the laterized concrete however increases as the curing age progresses
Sidoarjo Mud: A Potential Cement Replacement Material
Get PDFThis paper presents an experimental and analytical research conducted to study the properties of mortar when treated Sidoarjo mud was added into the mix replacing partially the cement content. The replacements were done at 0, 5, 10, 15, and 20%. Compression, tensile, porosity and Ultrasonic Pulse Velocity (UPV) tests were conducted to evaluate the effect of Sidoarjo mud in mortar. Analyses on the mud were also conducted through X-ray diffraction (XRD), X-ray Fluorescence (XRF), and scanning electron microscope with an energy dispersive X-ray analysis system (SEM-EDX). The results showed that the mud could be used as a cementitious material with optimum ordinary Portland cement (OPC) replacement at 10%
Volume Stability of Bitumen Bound Building Blocks
Get PDFThis paper covers results of laboratory investigations on the volume stability of masonry units incorporating waste materials bound with bitumen (Bitublocks), due to moisture adsorption, thermal exposure and vacuum saturation. The materials used were steel slag, crushed glass, coal fly ash, and 50 pen bitumen. The samples were produced in hot mix method, compacted, then exposed to moist and temperature. It was found that moisture adsorption from the environment caused the Bitublock to expand. The samples with less intense curing regime experienced lower expansion and became stable faster, and vice versa. Under thermal condition (at 70°C), the samples with less intense curing regime underwent higher expansion, and vice versa. They were also highly reversible. Their volume stability was found unique under water exposure. The expansion on first vacuum saturation cycle was irreversible, then largely reversible on the following cycles
Development of Spectral Hazard Map for Indonesia with a Return Period of 2500 Years using Probabilistic Method
Get PDFThis study is performed to develop spectral hazard map for Indonesia with a Return Period of 2500 years earthquake. It will be proposed for revision of the Indonesian hazard map in SNI-03-1726-2002 as response to the meeting organized by the Department of Public Works on 27- October-2008 in Jakarta. The meeting has decided to revise the Indonesia hazard map by referring to IBC-2006 where spectral acceleration values at Peak Ground Acceleration/PGA, 0.2 and 1.0 second with a return period of 2500 year will be applied for general buildings. The spectral hazard map was analyzed using total probability method and three dimensional (3-D) source models with recent seismotectonic parameters. Four source models were used in this analysis, namely: shallow background, deep background, fault, and subduction source models. Generally, the results of analysis show the values of PGA with a return period of 2500 years relatively higher 1.2-3.0 times than in SNI-03-1726-2002
Remediation of Diesel Fuel Contaminated Sandy Soil using Ultrasonic Waves
Get PDFUltrasonic cleaning has been used in industry for some time, but the application of ultrasonic cleaning in contaminated soil is just recently received considerable attention, it is a very new technique, especially in Indonesia. An ultrasonic cleaner works mostly by energy released from the collapse of millions of microscopic cavitations near the dirty surface. This paper investigates the use of ultrasonic wave to enhance remediation of diesel fuel contaminated sandy soil considering the ultrasonic power, soil particle size, soil density, water flow rate, and duration of ultrasonic waves application
Building Blocks Incorporating Waste Materials Bound with Bitumen
Get PDFThis paper described an investigation and evaluation which was carried out in the United Kingdom-UK, on the properties of masonry building block materials that incorporate waste materials, namely: steel slag, crushed glass, coal fly ash, rice husk ash (RHA), incinerator sewage sludge ash (ISSA), municipal solid waste incinerator bottom ash (MSWIBA) or shortened as IBA, bound with bitumen or asphalt, named as Bitublock. The binder used was 50 pen bitumen. The properties of the blocks evaluated were: compressive strength, density, porosity, initial rate of suction (IRS), creep, and volume stability. It was found that the Bitublock performance can be improved by optimizing porosity and curing regime. Compaction level of 2 MPa and curing regime of 200°C for 24 hours gave satisfactory bitublock performances that at least comparable to concrete block found in the United Kingdom (UK). The Volume stability (expansion) of the unit is affected by environment relative humidity
Owner and Contractor Perceptions Toward Factors Causing Delays in Structural and Finishing Works
Get PDFA construction project comprises of a number of work packages, which are subjected to delays. These delays may be caused by many on-site factors. The aim of this research is to represent owner and contractors perceptions towards delay factors that frequently occur in structural and finishing works. Data for analysis were gathered by distributing questionnaire. A total of 198 sets of questionnaire were gathered and used for subsequent analyses. In general, design changes during construction are perceived by respondents as the most frequent factor to cause delay in all structural and finishing works. The results also show that there are a number of differences between owner’s and contractor’s perceptions towards the occurrences of the factors. Whilst most contractors concern that information factors related to project design and scope frequently causing delays in construction works, owners consider many contractor originated factors, as most frequent delay causes
Estimation of Congestion Cost of Private Passenger Car Users in Malioboro, Yogyakarta
Get PDFCongestion is the condition when the hourly traffic demand exceeds the maximum sustainable hourly throughout of the link. The aim of this research is to estimate the congestion cost of private passenger car users in central business district along the corridor of Malioboro, Yogyakarta, Indonesia. The amount of the congestion cost is the difference between perceived and actual generalized cost in traffic jam condition. In this paper, only the congestion costs of private passenger car users are estimated, as they are expected to shift to buses. The generalized costs from origin zone i to destination zone j consist of vehicle operating cost, travel time cost, and pollution cost. This study shows that while the perceived generalized cost for private cars at Central Business District (CBD) Malioboro is IDR 3101.00 per trip, the actual generalized cost in traffic jam condition is IDR 5802.00 per trip, giving the estimation of congestion cost in CBD Malioboro for private passenger car users as IDR 2701.00 per trip