The Use of Stabilisation Materials in Cold-in Place Recycling of Flexible Pavement

This study was conducted to investigate the effectiveness of using silica fume, rice husk ash and lime as stabilisation materials in the cold-in-place recycling of flexible pavement. The cold-in-place recycling sample consists of 75% of recycling asphalt pavement taken from the site, 25% of crushed run and 5.05% of water. Asphalt mixture added with 1.5% cement (by total weight of a sample) was used as a control sample. Meanwhile silica fume, rice husk and limestone were added to samples at different percentages of 1, 3, 5, 7 and 9%. Five different tests; namely compaction test using vibrating hammer, Marshall Stability and Flow tests, unconfined strength test, indirect tensile modulus test and static creep test were conducted. It was found that all the stabilisation materials show inconsistent results compared to the 1.5% cement mixture. However, the use of 7% of rice husk shows good potential as a stabilisation material because of its strength, better withstand for higher loads and higher creep resistance compared to the silica fume and limestone mixtures. The results also showed that the optimum content of silica fume and limestone are 7% and 3% respectively to produce good cold-in-place recycling mixture.