Outdoor thermal comfort index in Malaysian urban areas

Rapid urbanisation and industrialisation have adversely impacted the urban environmental heat stress due to urban heat island phenomenon. These thermal environmental problems can be even more challenging to people living in urban areas with tropical hot and humid climatic conditions throughout the year. Buildings in urban area is one of the major elements that contributes to the heat stress problem. The objectives of the study are threefolds. First, to evaluate outdoor thermal comfort by using Universal Thermal Climate Index (UTCI) associated with regression equation during the hottest daily temperature based on 3 years of hourly climatic data at principal meteorological stations of five selected cities in Malaysia. Second, to simulate the current urban layout of the five cities with different types of area (i.e., residential, commercial and industrial areas) based on the analysed climatic input data of the worst case scenario by using Computational Fluid Dynamic (CFD) modelling to investigate its impact on UTCI. Third, to establish the most influential building arrangement parameter towards the outdoor thermal comfort. It was revealed that the UTCI values at five principal meteorological stations for the worst case scenario of heat stress were in the range of 35 °C to 37 °C. Meanwhile, the predicted UTCI levels due to the impact of buildings within the current urban layouts of the five cities were generally higher in the range of 39 °C to 47 °C. Alor Setar’s residential area was found to have the lowest UTCI while Alor Setar’s industrial area demonstrated the highest UTCI value. The predicted results from the Pearson coefficient correlation analysis revealed that packing density and H/W ratio are the two parameters that show significant impact toward UTCI with the correlation coefficient (R2) of 0.746 and 0.689 respectively. However, the result from MLR analysis showed that packing density is the one and only BAP that has strong positive influence towards UTCI with the correlation coefficient (R2) of 0.557

Technology of crack detection in reinforced concrete structures

Some crucial signs of structural failure that are critical for repair would be cracks on the structures as well as constant exposure that can result in severe environmental damage. Being able to detect cracks on structures is becoming an essential aspect of the technology of the construction industry. Destructive Testing and Non-Destructive Testing are the two methods used for structural crack detection. This study focused on the techniques used to detect cracks. Several effective methods to detect cracks were carried out and compared to identify the most suitable method in detecting cracks on structures within the demographics of Malaysia. Image processing techniques (IPTs) through the photogrammetry method, surface crack analysis program and Convolution Neural Network (CNN) were carried out to examine crack detection through measurement and monitoring from images. The distance was determined in this study for the physical properties, using both conductibility and accuracy. The photogrammetry method was able to conduct distance at 0.1 - 40 m, with an accuracy of up to 0.005 mm. Therefore, the surface cracks analysis provided 0.10 mm accuracy, while results on CNN had an accuracy of 0.95 mm (98.22 % and 97.95 % in training and validation). Results from physical properties showed that photogrammetry had the highest accuracy, while CNN has the least accuracy. Hence, this study concluded that Photogrammetry method and Convolution Neural Network (CNN) were both the most effective methods to be used in providing clear information and effective ways to detect crack on structures

Level of Service for Pedestrian Movement towards the Performance of Passenger Information in Public Transport Stations in Klang Valley

Rapid growth in car ownership in Malaysia plays a major role to traffic congestion. Hence, public transportation is crucial to cater the residents in high-density area especially in Klang Valley. Signage information in public transport station is one of an important passenger information system. Poor placement of sign information will decrease the efficiency of passenger flow and caused congestion in the station. Passenger information system is very useful for trip planning and decision making. Therefore, it is interesting to study the performance of passenger information system in focusing the movement behavior of pedestrian at non-peak period. Thus, the study on pedestrian movement during non-peak period on weekdays and weekends in mass transit stations and bus transit stations in Klang Valley was carried out by using video observation. The observation of the pedestrian movement was made in Mass Transit Station 1 in the middle of Kuala Lumpur and Mass Transit Station 2 in southern of Kuala Lumpur. The other site was focused at Bus Transit Station 1 in Putrajaya and Bus Transit Station 2 in Kajang. Findings shown that Mass Transit Station 1 having the best facility in terms of passenger information which the level of service obtained is LOS A, while the lowest level of service which is LOS E was obtained in Bus Transit Station 2

Eco-interlocking paving block (Eco-IPB) by using LDPE/Sand blends

Bitumen and interlocking paving blocks are the common materials used in the construction of flexible road pavements in Malaysia and other developing countries. In the last few years, more focus has been paid on the interlocking paving block when dealing with less durable area because of certain environmental and organizational limitations. Nonetheless, cement has been used as a bonding agent in the conventional concrete interlocking paving block (CIPB) and has a detrimental effect on the environment. This research was therefore conducted to examine the alternative material to paving block by substituting cement content with plastic wastes; so called as an Eco- interlocking paving block (Eco-IPB). The aim of this research was to produce a sustainable, lightweight, stiff and cost-effective product. In this research, the Eco-IPB was prepared in four different LDPE/sand blends of 1:1, 1:2, 1:3 and 1:4. The thermal analysis and physical tests were conducted to determine the temperature effect and physical performance of plastic bags. The performance of Eco-IPB was evaluated with regard to the density measurement, water absorption and compression test. The findings showed that the optimum LDPE/sand ratio of Eco-IPB of LDPE was 1:2 based on the high compressive strength of 20.80 MPa which had been achieved. Moreover, the widespread use of plastic waste as an alternative construction material will help to reduce plastic residues and promote green technology

A simulation model of reinforced concrete beam containing expanded polystyrene beads (EPS) and palm oil fueled ash (POFA) using finite element method

In this study, Expanded Polystyrene bead (EPS) and Palm Oil Fuelled Ash (POFA) will be used to replace several percents of cement and aggregate in reinforced concrete beam construction. EPS can produce lightweight concrete, and the use of POFA can produce high strength concrete and can also reduce waste disposal. The reinforced concrete beams were analysed using computer software called ABAQUS. The main reason Abaqus software is used as analytics software for this project is that the software is designed specifically for analyzing advanced structural and heat transfer. It is designed for both linear and nonlinear pressure analyses for both tiny and huge structures. This software can also be used to analyze the proposed reinforced concrete beam failure pattern of EPS and POFA. The percentage of EPS and POFA were 40% to 60% in concrete as replacement material. The information obtained from Abaqus is then used to verify the experimental results. The data also contains the appropriate percentage of EPS and POFA in the reinforced concrete beam where performance in terms of bending, pressure, and failure pattern is at maximum. The result shows decrease performance of RC beam containing 40-60% EPS and POFA

Eco-Interlocking Paving Block (Eco-IPB) by using LDPE/Sand Blends

Bitumen and interlocking paving blocks are the common materials used in the construction of flexible road pavements in Malaysia and other developing countries. In the last few years, more focus has been paid to the interlocking paving block when dealing with the area that less durability because of certain environmental and organizational limitations. Nonetheless, cement has been used as a bonding agent in the conventional concrete interlocking paving block (CIPB) and has a detrimental effect on the environment. This research was therefore conducted to examine the alternative paving block by substituting cement content with plastic wastes, it has called as an Eco-interlocking paving block (Eco-IPB). The aim of this research is to produce a sustainable, lightweight, stiff and cost-effective product. In this research, the Eco-IPB was prepared in four different LDPE/sand blends of 1:1, 1:2, 1:3 and 1:4. The thermal analysis and physical tests were conducted to determine temperature effect and physical performance of plastic bags. The performance of Eco-IPB was evaluated with regard to the density measurement, water absorption and compression test. The findings show that the optimum LDPE/sand ratio of Eco-IPB of LDPE was 1:2 based on the high compressive strength of 20.80 MPa had been achieved. Moreover, the widespread use of plastic waste as an alternative construction material will help reduce plastic residues and promote green technology. &nbsp

Compatibility issue related to the use of biodiesel with automotive materials

Biodiesel fuel can be used in diesel engine in accordance to the standard provided. However, a significant issue with biodiesel fuel was noted. Some of the fuel quality were outside the accepted range of the specification stated in the standard. Thus, this can be lead to the problem of utilization them in diesel engine. Moreover, material compatibility is the main concern whenever the fuel composition is altered in the fuel system. A large variety of metals and non-metals are worn as the material of construction for the various components of the fuel system. Introduction of biodiesel fuel often generate many problems in the components of the fuel system. This paper attempts to present the compatibility issue related to the use of biodiesel with automotive material

Assessment of Outdoor Thermal Comfort and Wind Characteristics at Three Different Locations in Peninsular Malaysia

Urbanization and rapid growth in construction have led to the problems of global warming and urban heat island throughout the world. In order to reduce these problems particularly in hot and humid climatic region, a research on current level of outdoor thermal comfort and wind characteristics based on the local weather conditions around Malaysia should be conducted. This paper reports on the analysis of outdoor thermal comfort level at hottest temperatures and wind characteristics at three locations in Peninsular Malaysia by using hourly climatic data recorded by Malaysian Meteorological Department (MetMalaysia). The level of outdoor thermal comfort was assessed based on the Universal Thermal Climate Index (UTCI). The results showed extreme heat stress conditions have occurred at Alor Setar, Kuantan, and Subang with UTCI values of 51.2°C, 49.7°C, and 49.0°C respectively taking into account only temperature data from the year 2012 to 2014. However, for 20 years data from 1994 to 2014, the calculated UTCI also showed extreme heat stress conditions with their respective values of 49.6°C, 43.8°C, and 49.7°C for Alor Setar, Kuantan, and Subang respectively. Meanwhile, the hourly mean wind speed for three years data at Alor Setar, Kuantan, and Subang, were 1.70m/s, 1.69m/s, and 1.63m/s respectively. The highest mean wind speed of 11.6m/s was observed at Subang, while no wind movement (i.e. 0m/s) was considered to be the lowest hourly wind speed for all three locations. The observed prevailing wind direction for all the three locations was from the north (0°). It can be concluded that Peninsular Malaysia is generally facing extreme heat stress problem due to unfavourable climatic conditions

Assessment of Outdoor Thermal Comfort and Wind Characteristics at Three Different Locations in Peninsular Malaysia

Urbanization and rapid growth in construction have led to the problems of global warming and urban heat island throughout the world. In order to reduce these problems particularly in hot and humid climatic region, a research on current level of outdoor thermal comfort and wind characteristics based on the local weather conditions around Malaysia should be conducted. This paper reports on the analysis of outdoor thermal comfort level at hottest temperatures and wind characteristics at three locations in Peninsular Malaysia by using hourly climatic data recorded by Malaysian Meteorological Department (MetMalaysia). The level of outdoor thermal comfort was assessed based on the Universal Thermal Climate Index (UTCI). The results showed extreme heat stress conditions have occurred at Alor Setar, Kuantan, and Subang with UTCI values of 51.2°C, 49.7°C, and 49.0°C respectively taking into account only temperature data from the year 2012 to 2014. However, for 20 years data from 1994 to 2014, the calculated UTCI also showed extreme heat stress conditions with their respective values of 49.6°C, 43.8°C, and 49.7°C for Alor Setar, Kuantan, and Subang respectively. Meanwhile, the hourly mean wind speed for three years data at Alor Setar, Kuantan, and Subang, were 1.70m/s, 1.69m/s, and 1.63m/s respectively. The highest mean wind speed of 11.6m/s was observed at Subang, while no wind movement (i.e. 0m/s) was considered to be the lowest hourly wind speed for all three locations. The observed prevailing wind direction for all the three locations was from the north (0°). It can be concluded that Peninsular Malaysia is generally facing extreme heat stress problem due to unfavourable climatic conditions