M. A. Hafez

Axle overloading at the southern part of the North-South Expressway in Malaysia

Overloaded vehicles may cause excessive wearing and damages to pavements, roads and bridges. They also threaten the road safety and contribute to several fatal accidents, thus the governments around the world have implemented axle load limitations. This paper investigates the overloading level at the southern part of North-South Expressway in Malaysia. The data were gathered from three survey stations located along the southern part of North-South Expressway for a period of one year. It was found that overloaded axles form a considerable percentage of the total volume. It has been recommended that enforcement level of axle load limitations along the southern part of North-South Expressway should be increased.

Rutting Load Equivalency Factors of Heavy Vehicles Operating in the Sothern Part of Malaysian Peninsula

In this study, load equivalency factors based on rutting criteria of heavy vehicles operating at the southern portion of Malaysian peninsula were developed. The study was based on the traffic volume and weight collected by three weight-in-motion stations for more than 6 million heavy vehicles. It was also based on the analysis of the effect of their weight on more than three hundred and fifty kilometers of flexible pavements. Based on the analysis made in this study, the average rutting load equivalency factors for each heavy vehicles type were developed. The developed rutting load equivalency factors could be used in flexible pavement design and rehabilitation purposes in the southern portion of Malaysian peninsula.

Prediction of axial limit capacity of stone columns using dimensional analysis

Stone column is the most favorable method used by engineers in designing work for stabilization of soft ground for road embankment, and foundation for liquid structure. Easy installation and cheaper cost are among the factors that make stone column more preferable than other method. Furthermore, stone column also can acts as vertical drain to increase the rate of consolidation during preloading stage before construction work started. According to previous studied there are several parameters that influence the capacity of stone column. Among of them are angle friction of among the stones, arrangement of column (two pattern arrangement most applied triangular and square), spacing center to center between columns, shear strength of soil, and physical size of column (diameter and length). Dimensional analysis method (Buckingham-Pi Theorem) has used to carry out the new formula for prediction of load capacity stone columns. Experimental data from two previous studies was used for analysis of study.

Fatigue Damage Ratios for Heavy Vehicles Operating in the Southern Part of Malaysian Peninsula

In this study, fatigue damage ratios caused by different types of heavy vehicles operating in the southern part of Malaysian Peninsula were developed. More than 6 million heavy vehicles’ traffic volumes and weights were collected from 3 Weight-In-Motion stations located at Tangkak, Yong Peng, and Sedenak. Through the analysis, an average fatigue damage ratios for each heavy vehicles types were developed to be used in flexible pavement design and rehabilitation purposes.

PFA-Cement Mixture for Sand Column Parameter Stabilization

Most of the waste materials produced by construction practice and factories are considered as waste products to be disposed. Disposal of these materials in landfills can inculcating ecological pollution and chemical effects on the environment. Rather than disposing and letting these waste materials unattended, finding a solution or method to recycle these waste materials are better, particularly for Fuel Ash. Therefore, this study was premeditated to investigate the effectiveness of using Pulverized Fuel Ash (PFA) in improving the geotechnical parameters. Shear Box Test and Unconfined Compression Test (UCT) were conducted on this study. Shear Box test was prepared by combining three materials; sand, cement and PFA and 7 days of curing time. The results show the average rate for the treated samples of shear strength increased in the range between 130 and 145 kPa, in parallel with the increase in percentage of sand and PFA. While for UCT test, the samples were prepared based on two different conditions: with and without lime to examine whether it would affect the strength of the cement (Sand-PFA) mixture or by using cement alone to see if it is enough to get the desired results. Samples were prepared by using various percentages of materials and 28 days of curing time. The results show the average rate of Unconfined Compression Strength (UCS) of samples are between 2 and 18 MPa which increases proportionally with increase in percentage of material. Based on data obtained from the experiments, it can be concluded that, the parameters of soil will be treated by increasing the percentage of material used. However, there are limitations on the addition of materials that are used because the graph will begin to show a decline if the percentage increase is added to the mixture exceeds the optimal dose.

A Study on Effect of PFA on Stabilized Material Using Direct Shear Test

Pulverized fuel ash (PFA) can be classified as hazardous Coal Combustion by-Product (CCP), which can contributes to the environmental pollution. According to (ACAA 2009), USA itself has produced approximately 125.5 million tons per annual of CCP which merely 56 million tons of these waste by-products has been successfully employed in applications and others still remain untreated. Disposal of these materials in landfills can deduce ecological. Thus, finding the solutions and methods of recycling these waste materials are needed, as it can be used as one of the materials in construction projects, engineering purpose or stabilizing process. Therefore, a study on direct shear test have been conducted and the data collected from this study were compared and analyzed through various methods to find out how does PFA works on improving geotechnical properties.