Papers by Author: Amiruddin Ismail

Abstract: Bonding strength of bitumen is one of the most important properties in need of independent evaluation. Conducting a pull-off test to determine the bonding strength of bitumen can be done using the Universal Test Machine (UTM). In this work, the UTM was used to investigate the effect of adding an additive to with a 60/70 penetration grade bitumen; the additive used was nano-clay at a percentage of 2% and 4%. A designed mold was fabricated and used with granite and stainless steel substrates. The investigation covered the influence of variation in the mixing process (mixing duration and power of rotation during mix) on the bonding strength of the samples. X-ray diffraction (XRD) was used to discover the nano-clay exfoliation within the binder structure. Also, empirical tests - penetration and softening point tests - were conducted. The results varied according to variation in percentage of additive, substrates used and the mixing process. The bonding strength and softening point results were able to identify the effect of the additive, and were able to detect changes caused by the adding condition; both were very well correlated, unlike the penetration test result which had a weaker correlation with bonding strength.

Abstract: Due to lack of previous study on applying polymer additives in road base construction, this research presents experimental results on the improvement of long-term road base performance by the addition of carboxylated styrene–butadiene emulsion (Rovene^® 4045) and Portland cement. The specimens stabilized with Portland cement (0–6%) and Rovene^® 4045 (5–10%) and then subjected to different stress sequences to study the wetting and drying (WD) and wheel tracking (WT) tests on the 7-day-cured specimens. Results of tests conducted to assess the specimens’ resistance to WD cycling showed that the addition of a 4% Portland cement–7% Rovene^® 4045 mixture resulted in reductions of 86.99% in water absorption, volume changes of 88.55%, and weight changes of 92.84% relative to a sample with only 4% cement after 12 WD cycles. The permanent strain behaviour of the samples was assessed by the WT test. The results of WT test showed that the permanent deformation characteristics of the mixture were considerably improved by utilization of Rovene® 4045 modification, which resulted in reductions of 218.9% at 25 ^oC, and 356.8% at 50 ^oC in permanent strain of the mixture respectively. Therefore, this research nominates a new polymer additive having outstanding engineering properties and environmental friendly.

Abstract: Polymer modified bitumens have tended to be the most popular among the various types of modified binders that are available worldwide. Polymer modification significantly alters the rheological characteristics of the binder, thereby requiring the use of fundamental rheological testing methods to provide an indication of the performance of the binder and subsequently the asphalt mixture. In this paper the characterization of bitumen modified with epoxidized natural rubber (ENR) was done with four percentages of ENR content. The effects of the modifier on the conventional properties, storage stability and rheological properties were investigated. The results indicated that storage stability of ENR modified bitumens (ENRMB) were mainly dependent on the ENR content. ENR reduced the temperature susceptibility. The degree of the improvement generally increased with ENR content up to 9%.

Abstract: Cement-Treated Base (CTB) is a non-conventional method used in road bases materials to improve its engineering properties due to the hardening of cement when moisture is present and extends the period of curing times. This study investigates the effects of cement additive on properties of base layer using laboratory mechanistic evaluation of stabilized soil mixtures. Laboratory tests conducted were Unconfined Compressive Strength (UCS), Indirect Tension test for Resilient Modulus (ITRM) and Flexure Strength (FS) tests. The results revealed that by adding Portland cement, the mechanical properties of the mixture have improved where the UCS is found to be an important quality indicator. In addition, the variables that influenced these tests, which are cement content, curing time, moisture content, and dry density, play important role to determine the performance of CTB. This paper presents the finding of a correlation conducted to analyse the influences of these variables using regression and ANOVA to establish significant models with the aim of predicting the strength base on mixture parameters. Keywords: Cement-Treated Base, Unconfined Compressive Strength, Indirect Tension test for Resilient Modulus, Flexure Strength, Moisture Content, Dry Density, Regression Analysis.

Abstract: Good decisions about transportation investments and policies require accurate information to the characteristic of transportation system alternatives that are acceptable to individual and social are most important and necessary to identification and consideration. The primary aims of this research are to clarify the relationships between urban vehicle’s traits that are acceptable for individual and social from urban planning perspective. The study finds that are acceptable vehicle’s characteristics and do effects on individual or traveller include travel time, travel costs, safety and security, convenience, available and assurances. It is worth mentioning factors such as climate, geographic location, cultural factors and economic status are factors that will be affecting on the urban transportation traits from individual and society perspective. Methodology of this research is on based of field study (field observation, data collection, take photo and some interview) and library study (literature review, study about title and else). The study wants to do discuss via analytically and descriptively methods. The aims here are to gain a better understanding of the variables that effect on the acceptable urban vehicle traits for individual. Therefore, research will focus on identification and consideration of most important traits of the urban vehicles that is acceptable for the passenger or individual perspective. This is not only solving way to global problems about urban vehicle's traits from individual and society perspective because of various factors with different traits will become in order to play.

Abstract: Change order is a frequent phenomenon in most construction projects. However, these changes can be controlled when their causes are known. This report is set to find out the various techniques through which this phenomenon can be controlled most especially in the roadway construction projects in south of Iran. In order to reduce this occurrence to the minimum, certain mechanisms have been identified as being very effective and these are clearly the project objectives and scope of change order of work, provision of complete documentation, finalize the design during the design phase. The outcomes of this study would provide necessary information that may be used by employers and contractors to minimize cases of change orders in construction projects. Moreover, it is anticipated that the results of this study will assist greatly in reducing the total cost of construction works and the time of completion of the project hence increase the efficiency of the work.

Abstract: Nowadays, the total volume of passenger trip demand has increased due to population and economic growth. In this situation , government policy encourages people to use public transportation for inter-city trips. In the meantime, buses are the most widely used in transit technology today. The most important issue in buses service is timely arrival. Due to the limited capacity of the streets and increasing car production, we cannot devote a specific lane to bus operation to separate their operation from other traffic. Generally, actual arrival time of buses in comparison to planned arrival time occurs in three scenarios : sooner, on-time, and later. This article represents different scheduling model to achieve timely arrival. For this purpose we tested two different scenarios by actual public bus operation. The data was obtained in the city of Tehran, since Iran was used in this study.

Abstract: Bus networks occupy less space in city streets, and compared to other kinds of public transportation, need less investment cost. An accurate bus operation schedule which considers actual arriving and departure time is essential for bus companies, due to high passenger demand. In real-world cases, there are daily differences in the frequency of bus dispatch from the terminal, and headway of buses between each bus bay along their route, depending on peak hour traffic and resulting congestion. In this research we studied effective parameters for preparation of proper bus operation scheduling. Measures are essential to ensure that buses receive priority over other traffic, if they are to be attractive to passengers. Finally, we suggest some solutions for lessening interval time in headway and frequency scheduling for bus services. Data obtained from an actual bus operation in the city of Tehran in Iran was used in this study.

Abstract: In bus networks there are many stations used for boarding and alighting passengers along the bus route. In designing bus stop location three sides approach to be considered; the big picture, street side and curb side. Apiece of three sides have directly affects in the bus scheduling. The effectiveness of bus operation will depend on number of bus stops and its spacing. Basically, bus stations have two kinds: bus stop, use to service passengers in one bus line and bus interchange (terminal) use to share station between some bus lines. This article described a survey on bus stop location efficiency in bus operation where study on bus stop location in three points: near-side, far-side and mid-block were considered. It has been highlighted bus stop location in situation mid-block has higher efficiency than others situations.

Abstract: Nowadays, delays problem are important issue in preparing schedule for public transportation. It is related to behaviour of passengers, behaviour of transportation means and interaction with traffic. Behaviour of passengers are including: demand patterns of passengers, fare payment and waiting time in station and in-vehicle. Behaviour of transportation means included fleet size and frequency of operation. The most interaction between public transportation and others traffic is in traffic congestion. In this paper, we studies different behaviour of passengers duration operation time in two points: in-station and in-vehicle. They are including: arrival rate of passengers, kinds of fare payment and waiting time. For illustrate behaviour of passengers on delays problem we survey they affects in bus operation. Hence, a case study based on an actual public bus operation in Tehran, Iran is used to demonstrate it.