Influence of aggregate packing structure and bitumen-aggregate binding characteristic on the mechanistic performance of hot-mix asphalt concrete

• Main Author: Muhammad Izwan Ibrahim.
• Other Authors: Wong Yiik Diew
• Format: Final Year Project
• Language: English
• Published: 2010
• Subjects: DRNTU::Engineering::Civil engineering::Transportation
• Online Access: http://hdl.handle.net/10356/39692
• Institution: Nanyang Technological University

Numerous trials and samples were conducted in the selection of a favourable aggregate blend for a Hot-Mix Asphalt (HMA) which is a time consuming process. Hence, a method was developed as a tool to effectively analyse and evaluate HMA in the laboratory and relate it to the field performance. Aggregate gradation is one of the most important parameters in HMA. The method of designing aggregate gradation is called the Bailey Method. The Bailey Method is a method that focuses on aggregate packing structure to develop a proper gradation for a mix. It provides a good starting point for mix design and a good tool to estimate air voids and VMA change in HMA. It affects the engineering properties of a mix such as stability, durability, permeability, and fatigue resistance. In Singapore, W3B gradation as specified by Land Transportation Authority (LTA) has been the benchmark pavement mix design for the past few years. A new blend mix named as W3D1 was thus created through the application of Bailey Method, a method that optimizes aggregate packing structure. The new blend was compared against the conventional W3B mix on their performance. The new blend is a fine-graded mix constituting 60% of fines while W3B has 45% of fines. The selected optimum binder contents for W3D1 and W3B were 5.16% and 5.00% respectively. The new blend mix attained good results in Marshall Stability and Resilient Modulus Test. However, the conventional W3B mix exhibited better creep resistance than the new W3D1 mix.