Superpave grading for high traffic volumetric criteria
The Superpave mix design system is a comprehensive method of designing paving mixes determined by the traffic, climate, and structural section of a particular pavement site. The first project of the Superpave mix design in Malaysia was in 1996. The application was in the technical specifications for runway and taxiway pavement for Kuala Lumpur International Airport (KLIA) project. In the meantime, research work carried out by the Public Works Department (PWD) showed that distresses happened usually on heavily trafficked roads and becomes a major problem as axle loading increased. It is clearly shown that there are inabilities of conventional mix design methods to control the performance of materials. In conjunction with that, the Superpave has been proven in western countries as the best mix design method because it offers performance-based specification for asphalt pavement mixtures. For this reason, this method is selected for the laboratory mix design. After all, the aim of this research is to evaluate the properties of the Superpave mixture design using Malaysian materials. The properties of the mixture design intended to satisfy for heavy duty roadways. As a summary, several trial aggregate gradations were developed and initial trial asphalt content has been calculated for four categories; CLV, CHV, FLV, and FHV. And finally, three design aggregate structures are selected and it's has proven suits for heavy duty roadways volumetric criteria.
Fatigue Modelling for Stone Mastic Asphalt (SMA)
Fatigue cracking is one of the major distresses found in many asphalt pavements. The 
premature cracking of the pavements results in the increased annual cost of resurfacing, 
maintenance and rehabilitation. Generally, any asphalt mix is tested in the laboratory 
and predictions are made using the performance curves and local conditions. However, 
in Malaysia there are not any pavement prediction models developed yet that can be used 
to predict the asphalt mix's fatigue life performance under the local environmental 
conditions. This paper looks into the fatigue characteristics of SMA by using local 
materials and environmental conditions. For the purpose of evaluation SMA14 ( SMA 
with 14mm aggegate as nominal) with 5 different gradations within the JKR's ACW14 
gradation envelope were used. The repeated load indirect tensile tests at three different 
temperatures (30°C, 40°C, 50°C) and five different dynamic loadings (500N, 750N, 
1000N, 1250N, 1500N) were carried out under stress controlled mode using the MATTA 
Machine. The fatigue performance test results plotted on a logarithmic scale of fatigue 
strain and load repetitions showed a good agreement with the historic trend of the 
fatigue data. The logarithmic relationship between fatigue loading and strain was 
evaluated and found to be linear at certain reliability regardless of the testing condition 
and mix parameter. This indicates that the fatigue model for SMA is a function of asphalt 
volume, resilient modulus and the fatigue strain values.
Fatigue of Asphalt Concrete Mixtures—Summary of Existing Information
DATA ARE PRESENTED ON THE FATIGUE BEHAVIOR OF ASPHALT CONCRETE MIXTURES BASED ON A REVIEW OF THE LITERATURE, AS WELL AS RESEARCH, WHICH ILLUSTRATE THE EFFECTS OF A NUMBER OF MIXTURE VARIABLES ON FATIGUE RESPONSE AND INCLUDE AN INDICATION OF THE INFLUENCE OF: MIXTURE STIFFNESS, AIR VOID CONTENT, AGGREGATE GRADATION, AGGREGATE TYPE, ASPHALT CONTENT, AND ASPHALT TYPE. A LITERATURE REVIEW INDICATES THE VARIATION TO BE EXPECTED ON TYPICAL CONSTRUCTION PROJECTS. THIS INFORMATION TOGETHER WITH THE FATIGUE DATA PRESENTED PREVIOUSLY ALLOWS THE ENGINEER TO ASSESS THE RELATIVE IMPORTANCE OF THESE MIXTURE VARIABLES ON PREDICTING THE PERFORMANCE OF PAVEMENTS. ASPHALT CONTENT AND TEST TEMPERATURE APPEAR TO BE MORE CRITICAL THAN THE VARIATION ASSOCIATED WITH AGGREGATE GRADATION, ASPHALT HARDNESS, AND AIR VOID CONTENT. /DOT/