Feasibility study of roller compacted concrete with recycled aggregates as base layer for light-traffic roads

摘要

This research aims to produce roller compacted concrete (RCC) using recycled aggregates (RAs) from construction and demolition waste (CDW) with low cement content. Previous research has confirmed that RA performs favourably when applied to a road base layer as a granular material or as a cement-treated granular material. In addition, previous studies have made progress in analysing the feasibility of using RCC with different types of RA, such as recycled concrete aggregate (RCA) and recycled pavement aggregate (RPA). Under this framework, the technical feasibility of using RCC with a 100% coarse RA incorporation ratio and low cement content in the base layer of light-traffic roads was determined. For that purpose, two series of RCC mixtures were produced with different cement contents: 150 and 250 kg/m(3). Each series consisted of RCC mixtures with one natural aggregate (NG) and three different types of RA, specifically, one RCA and two mixed recycled aggregates (MRA), as coarse fraction. The percentage of ceramic particles in the RA ranged from 2.5% to 23.4%. The mechanical properties (e.g. the compressive strength, splitting tensile strength and elastic modulus) and drying shrinkage were studied in the RCC specimens produced. Mechanical properties were diminished as percentage of ceramic increased. These reductions in mechanical properties were near 30% for the RCC with RA with the greatest ceramic elements, respect to RCC with NG. The results support the feasibility of using RCC with a 100% coarse RA incorporation ratio and low cement content to form light-traffic-road base layers, such as residential streets, sidewalks and bike lanes.