17 research outputs found
Risk Probability of Time and Cost on Building Construction Project: A Monte Carlo Simulation
Construction project has never been avoided by not only low risk but also high risk. It can also occur in building and infrastructure construction project of Aceh Regional Intelligent Agency (BINDA) office complex. The complex structural works can impact the significant risk to the project construction process. To minimize the risk, it is required to review the risk analysis to the time and the cost. The problem of the research was how many probabilities of the highest risk by using Monte Carlo. The objective of the research was to analyze the highest risk probability percentage of time and cost in building construction project by using Monte Carlo simulation. Sampling technique used was census sampling by using 18 respondents. The variables used were contractual risk, construction risk, material and equipment risk, design and technology risk, and force majeure risk. The output of risk acceptability level analysis by using probability and impact found that the dominant risk in undesirable category is wrong implementation as the highest value of 7.50 risk value. The simulation output of Monte Carlo by using @risk software resulted that project duration time was 460 days on 99% probability. For probability distribution of cost estimation resulted that budget plan estimation was IDR 1,991,000,000 on 99% probability, so the project cost estimation can get the benefit as 1.00% by using @risk simulation. Therefore, the response provided is coordination to supervision consultant and owner
Statistical Analysis of Accident Patterns and The Causes at A State Road in Perlis
Data from the World Health Organization have stated that each year, approximately 1.3 million road users are at high risk of a road traffic accident. Therefore, this study aims to evaluate the accident patterns and causes at a state road of Kangar to Alor Setar. The methods used to evaluate the accident patterns are the chi-squared test (CST) and level of service (LOS) survey. The Pearson CST shows that the significant factors for accidents are the age of the drivers, in which people below 30 years old are likely to be involved in accidents ( = 0.037), and type of vehicles used, in which motorcycles are more prone to be involved in accidents ( = 0.000). However, gender shows an equal risk for accident involvement ( = 0.911). The LOS E is observed on evenings of Monday and Friday, indicating the unstable flows of traffic during those periods. Partial least squares structural equation modelling is used to evaluate the causes of accidents from the road user’s perspective via a questionnaire. Before distribution, the questionnaire underwent a pilot study to ensure its validity and reliability. Four hypotheses were developed with the following independent variables: human factors, vehicle factors, environment factors and road condition factors. Results show that the majority of the road users (33.3%) travelled 1 to 3 times per week and 23.1% of them were involved in accidents while travelling on this road. The validity test via the structural model shows that the most significant factors affecting the relationships to the accidents are the road factors (t = 6.166, p = 0.000), the vehicle factors (t = 4.3399, p = 0.000) and the human factors (t = 2.893, p = 0.005). Thus, the factors are significant to the causes of accidents on this road. Countermeasures that emphasise these factors are very important to be considered by authorities to reduce accidents on this road
Statistical Analysis of Accident Patterns and The Causes at A State Road in Perlis
Data from the World Health Organization have stated that each year, approximately 1.3 million road users are at high risk of a road traffic accident. Therefore, this study aims to evaluate the accident patterns and causes at a state road of Kangar to Alor Setar. The methods used to evaluate the accident patterns are the chi-squared test (CST) and level of service (LOS) survey. The Pearson CST shows that the significant factors for accidents are the age of the drivers, in which people below 30 years old are likely to be involved in accidents ( = 0.037), and type of vehicles used, in which motorcycles are more prone to be involved in accidents ( = 0.000). However, gender shows an equal risk for accident involvement ( = 0.911). The LOS E is observed on evenings of Monday and Friday, indicating the unstable flows of traffic during those periods. Partial least squares structural equation modelling is used to evaluate the causes of accidents from the road user’s perspective via a questionnaire. Before distribution, the questionnaire underwent a pilot study to ensure its validity and reliability. Four hypotheses were developed with the following independent variables: human factors, vehicle factors, environment factors and road condition factors. Results show that the majority of the road users (33.3%) travelled 1 to 3 times per week and 23.1% of them were involved in accidents while travelling on this road. The validity test via the structural model shows that the most significant factors affecting the relationships to the accidents are the road factors (t = 6.166, p = 0.000), the vehicle factors (t = 4.3399, p = 0.000) and the human factors (t = 2.893, p = 0.005). Thus, the factors are significant to the causes of accidents on this road. Countermeasures that emphasise these factors are very important to be considered by authorities to reduce accidents on this road
The Behavior of Non-Destructive Test for Different Grade of Concrete
Rebound hammer are prefer as non-destructive testing methods; where compression test as destructive test. A general series of tests for rebound hammer and destructive test was carried out at heavy concrete laboratory to obtain the desire result. A set of concrete cubes of sizes 100 x 100 x 100 mm had been casted and subjected to water curing which was held for 7, 14, 21 and 28 days to get the exact result of cube strength and rebound number. Rebound hammer testing were initially done before the compression test. The data obtained from each test has been evaluated and tabulated in this report. From this research, the variation between predicted strength and experimental strength for rebound hammer testing was 1.6%. This indicated rebound hammer testing managed to predict the strength more accurately. However, non-destructive test shown a margin of less than 10% error compare to destructive test
Characteristics of Concrete Exposure in the Marine Environment
The characteristics of concrete in the marine environment with various grades of concrete of grade 30, 35, and 40 investigate in this research. The objective of this study is to identify the optimum grade of concrete in the marine environment. Several test was conducted such as water absorption, density, ultrasonic pulse velocity (UPV), and compressive strength. The results show that the optimum grade of concrete in the marine environment is grade 40, which has the lowest water absorption of 8%, the highest density test of 2399 kg/m3, the highest UPV test result of 4723.249 m/s, and the highest compressive strength test of 31.63 MPa. The high result indicates the high quality and durability of the concrete. The study contributes to the understanding of the characteristics of concrete in the marine environment and provides valuable information for the selection of the appropriate grade of concrete for marine structures
Sustainability Relationship between Space Configuration, Activity Patterns, and Mosque Acoustics Quality
The Great Mosque of Yogyakarta was built in 1773. This mosque has a traditional architectural style. This study investigates the relationship between the mosque's architectural form, the activities inside it, and its acoustic characteristics. It employed quantitative and qualitative methods, including sound pressure level (SPL) measurement, reverberation time, and architectural and activity observations. Acoustic measurements, architectural observations, and activities are conducted inside and outside the mosque from morning to night for one week. The research finding is a spatial continuity pattern identified as the gradation of SPL value. Consistent continuity of SPL values in accordance with the nature of activities hierarchy. The result of this study is to improve mosque noise control by arranging outdoor and indoor spaces in a sustainable manner. © 2022 Authors. All rights reserved
Microstructural aspects in steel fiber reinforced acrylic emulsion polymer modified concrete
Scanning electron microscope observations of polymer-free and polymer-modified cements have shown that the polymer particles are partitioned between the inside of hydrates and the surface of anhydrous cement grains. For optimum dosage of acrylic emulsion polymer with 2.5%, the C-S-H gel in this structure is finer and more acicular. Some polymer adheres or deposit on the surface of the C-S-H gel. The presence of acrylic emulsion polymer confines the ionic diffusion so that the Ca(OH)2 crystallized locally to form fine crystals. The void in the structures seems to be smaller but no polymer films appears to be bridging the walls of pores although many polymer bonds or C-S-H spread into the pore spaces. In addition to porosity reduction, acrylic emulsion polymer modified the hydration products in the steel fiber –matrix ITZ. The hydration product C-S-H appeared as a needle like shape. The needle-shaped C-S-H increases and gradually formed the gel, with needles growing into the pore space. The phenomenon is more obvious as curing age increased
Microstructural aspects in steel fiber reinforced acrylic emulsion polymer modified concrete
Scanning electron microscope observations of polymer-free and polymer-modified cements have shown that the polymer particles are partitioned between the inside of hydrates and the surface of anhydrous cement grains. For optimum dosage of acrylic emulsion polymer with 2.5%, the C-S-H gel in this structure is finer and more acicular. Some polymer adheres or deposit on the surface of the C-S-H gel. The presence of acrylic emulsion polymer confines the ionic diffusion so that the Ca(OH)2 crystallized locally to form fine crystals. The void in the structures seems to be smaller but no polymer films appears to be bridging the walls of pores although many polymer bonds or C-S-H spread into the pore spaces. In addition to porosity reduction, acrylic emulsion polymer modified the hydration products in the steel fiber –matrix ITZ. The hydration product C-S-H appeared as a needle like shape. The needle-shaped C-S-H increases and gradually formed the gel, with needles growing into the pore space. The phenomenon is more obvious as curing age increased
Engineering Behavior of Concrete with Recycled Aggregate
Concrete is extensively used as construction materials in Malaysia. Concrete contributes suitable feature for construction industry for instance durability, adequate compressive strength, fire resistance, availability and is economic as compared to other construction materials. Depletion of natural resources and disposal of construction and demolition waste remarkably claim environmental threat. In this paper, the engineering behavior, durability, and concrete microstructure of recycled concrete aggregates (RCA) on short-term concrete properties were investigated. The studied concrete at design mix proportion of 1:0.55:2.14:2.61 (weight of cement :coarse aggregates :sand :water) used to obtain medium-high compressive strength with 20%, 50%, and 100% of RCA. Results show that for the same water/cement ratio, RCA replacement up to 50% still achieved the targeted compressive strength of 25 MPa at 28 curing days. Addition, at similar RCA replacement, the highest carbonation depth value was found at 1.03 mm which could be attributed to the pozzolanic reaction, thus led to lower carbonation resistance. Scanning electron microscopy microstructure shows that the RCA surface was porous and covered with loose particles. Moreover, the interfacial transition zone was composed of numerous small pores, micro cracks, and fissures that surround the mortar matrix. On the basis of the obtained results, recommendable mineral admixtures of RCA are necessary to enhance the quality of concrete construction
Engineering Behavior of Concrete with Recycled Aggregate
Concrete is extensively used as construction materials in Malaysia. Concrete contributes suitable feature for construction industry for instance durability, adequate compressive strength, fire resistance, availability and is economic as compared to other construction materials. Depletion of natural resources and disposal of construction and demolition waste remarkably claim environmental threat. In this paper, the engineering behavior, durability, and concrete microstructure of recycled concrete aggregates (RCA) on short-term concrete properties were investigated. The studied concrete at design mix proportion of 1:0.55:2.14:2.61 (weight of cement :coarse aggregates :sand :water) used to obtain medium-high compressive strength with 20%, 50%, and 100% of RCA. Results show that for the same water/cement ratio, RCA replacement up to 50% still achieved the targeted compressive strength of 25 MPa at 28 curing days. Addition, at similar RCA replacement, the highest carbonation depth value was found at 1.03 mm which could be attributed to the pozzolanic reaction, thus led to lower carbonation resistance. Scanning electron microscopy microstructure shows that the RCA surface was porous and covered with loose particles. Moreover, the interfacial transition zone was composed of numerous small pores, micro cracks, and fissures that surround the mortar matrix. On the basis of the obtained results, recommendable mineral admixtures of RCA are necessary to enhance the quality of concrete construction