Self-cementing mechanisms of recycled concrete and masonry aggregate

Towards a holistic approach in the design of flexible asphalt pavements, it is important to understand the integral role of the underlying layerworks for the well-functioning of the pavement as a whole. Balancing the utilisation of high quality materials, against the increasing depletion of natural materials is a driving force in investigating alternative resources for pavement construction. Some countries use recycled materials as a matter of normality due to lack of quality materials and its proven structural capacity. In this context, construction demolition waste is researched in this paper. Historically, the approach in using this material has been to establish the short term performance (i.e no curing of the material before testing). In this context, the behaviour of construction demolition waste exhibit similar affinity of governing variables i.e degree of compaction, moisture content (saturation level) and stress dependency to that of granular materials. Mechanisms that manifest over time such as self-cementing of latent unhydrated hydraulic binder are not included when these short-term laboratory tests are performed and the behaviour analysed. In this research, a laboratory experimental program including unconfined compression-, monotonic and multi-staged cyclic testing for various ages of RCA and curing times were performed. An analysis of these results revealed a significant influence of the residual unhydrated cement on the material behaviour. This paper discusses these conclusions towards a better understanding of the potential behaviour of these types of materials and allows for the consideration of previously ignored material phenomena towards maximisation of the benefits of self-cementation.

Language

  • English

Media Info

  • Pagination: 7p
  • Monograph Title: 11th Conference on Asphalt Pavements for Southern Africa: CAPSA15, 16-19 August 2015, Sun City, South Africa

Subject/Index Terms

Filing Info

  • Accession Number: 01597116
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Apr 22 2016 11:15AM