Utilisation of recycled concrete aggregates in asphalt mixture

• Main Author: Lau, Kia Kgoon.
• Other Authors: Wong Yiik Diew
• Format: Final Year Project
• Language: English
• Published: 2012
• Subjects: DRNTU::Engineering::Civil engineering::Construction technology
• Online Access: http://hdl.handle.net/10356/48982
• Institution: Nanyang Technological University

The feasibility of full substitution of coarse and fine recycled concrete aggregates (RCA) into porous asphalt (PA) mixture for light traffic road pavement construction, in particular pedestrian and bicycle paths, were investigated in this project. Besides investigating the use of RCA in the PA mixture, the effects of three filler types (RCA filler, hydrated lime and kaolin) on the asphalt mixture were also examined. Nine small specimens and two large PA specimens incorporating each filler type were batched for performance testing. The mix design followed earlier research project by Yeung (2009). The three PA blends are denoted PA RCA-1, PA RCA-2 and PA RCA-3 for RCA PA mixture using RCA filler, hydrated lime and kaolin, respectively. Permeability test, marshall test, skid resistance test, rutting test and dynamic creep test were conducted. Permeability results showed that all the specimens were highly porous, with PA RCA-1 being the most permeable, hence indicating the highest voids content. However it is less stiff and deforms the most under rutting and creep test. Marshall stability test showed that PA RCA-2 can withstand the highest loading before failure but it is ranked last in terms of drainage ability. PA RCA-3 had the best performance against creep and rutting deformation, but its low resistance to skid makes it less suitable to be used for pedestrian and bicycle paths. The overall investigation reveals that full substitution of RCA into porous asphalt mixture for light traffic road pavement construction is feasible. Nevertheless, more in depth studies and research are recommended.