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.
THE SUPERPAVE MIX DESIGN MANUAL FOR NEW CONSTRUCTION AND OVERLAYS
The Superpave mix design system is a comprehensive method of designing paving mixes tailored to the unique performance requirements dictated by the traffic, environment (climate), and structural section at a particular pavement site. It facilitates selecting and combining asphalt binder, aggregate, and any necessary modifier to achieve the required level of pavement performance. This laboratory manual presents Superpave mix design system in a complete, step-by-step format. It is intended for engineers and technicians in public and private organizations to use when designing paving mixes for all classes of highways, from farm-to-market roads to urban freeways. An essential companion to this manual is "The Superpave Mix Design System Manual of Specifications, Test Methods and Practices." The Superpave software program--"The Superpave Specification, Mix Design and Support Program"--and its users manual are also necessary to take full advantage of the mix design system.
APPLICATIONS OF THEORY IN THE DESIGN OF ASPHALT PAVEMENTS
Pavement design, like other aspects of engineering design, requires that engineers have the ability to analyze pavement structures in terms of significant system parameters. Moreover, it is necessary that such analyses incorporate essential features of observed pavement performance and appropriately measured values of the parameters to make the necessary quantitative evaluations required for design. It is generally recognized, however, that the parameters involved together with their interrelationships are complex. In recent years a number of attempts have been made to formulate, in a systematic manner, pavement design systems which bring these factors together as a part of the development of improved methods of pavement design, methods which will have the capabilities to: (1) accommodate the continually changing loading requirements; (2) better utilize available materials; (3) accommodate new materials which might be developed; (4) better define the role of construction; and (5) improve the reliability for performance prediction (or of the design estimate). While it is difficult to develop one pavement design system which, at this stage in time, will incorporate all desirable factors, it is possible to develop a series of subsystems the goal of each of which is to minimize a particular form of distress. To minimize the effects of various distress mechanisms, design frameworks (subsystems) have been established and specific formats are developed. These subsystems parallel the design approach widely used in Civil Engineering practice in which a structure is selected (designed), its behavior under anticipated service conditions analyzed, and its adequacy with respect to a specific distress criterion determined. A discussion of the most recent methods available to examine each of these subsystems is included. Considering this information, the authors recommend a specific technique to solve for each distress mode recognizing present limitations in materials characterization techniques and availability of solutions for boundary value problems representative of pavement structures as well as present limitations in knowledge of traffic, environmental, and construction effects. The concluding section is concerned with a discussion of factors not now included in the subsystems described in the report. Consideration is given to optimization, and the applicability of dynamic programming techniques to optmizing the solution of the pavement design problem is discussed. Included in the discussion is the ability of dynamic programming to consider the following factors: (a) Adaptive System - the incorporation of new information gained through observations of performance to predict future performance, (b) Sensitivity - the influence of individual parameters on the total system, and (c) Stochastic Processes - the ability to evaluate the degree of uncertainty in the information that forms the basis for design. /AUTHOR/