Assessment of construction and demolition waste materials for sublayers of low traffic rural roads

The need for exploiting massive amounts of natural raw materials for constructing pavements of roads as a key element for development of infrastructures in modern age, together with enormous production amounts of wastes related to civil engineering activities as biggest portion of solid waste generated all over the world, have highlighted the importance of utilizing recycled aggregates of these materials in road pavement layers. The key factor in this quest, is to evaluate load-bearing abilities of various kinds of waste aggregates. Aggregates of reclaimed asphalt, pre-stressed or normal concrete, masonry and demolition waste (CDW) exhibit different behavior under loading after compaction. The ideal situation would be to achieve the densest compacted and durable layer in order to get the highest durability, comparing to traditional road materials. In this study, aggregates from four types of recycled materials are being subjected to study for unbound and cemented pavement layers. Initial laboratory evaluations of size and composition are followed by constructing a field on a subgrade with high non-homogenous surface. Vibrating elastic modulus (Evib) for these materials were determined by Continuous Compaction Control (CCC) Oscillating Rollers. It is observed that, despite the weaknesses arisen from weak components such as masonry and elongated tiles, the stabilized distribution of the particle size can accelerate reaching to final compaction of unbound aggregates with roller passing. This process could be repeated with more or less same pattern in cemented layer, which exhibited an enhanced stiffness and uniformity in order to minimize the weak parts of non-uniform subgrade layer, and provide a high rigid pavement.