Improvement of Bearing Capacity in Recycled Aggregates Suitable for Use as Unbound Road Sub-Base

Laura Garach; Mónica López; Francisco Agrela; Javier Ordóñez; Javier Alegre; José Antonio Moya

doi:10.3390/ma8125493

Improvement of Bearing Capacity in Recycled Aggregates Suitable for Use as Unbound Road Sub-Base

Materials (Basel). 2015 Dec 16;8(12):8804-8816. doi: 10.3390/ma8125493.

Authors

Laura Garach¹, Mónica López², Francisco Agrela³, Javier Ordóñez⁴, Javier Alegre⁵, José Antonio Moya⁶

Affiliations

¹ Department of Civil Engineering, University of Granada, Severo Ochoa s/n, Granada 18071, Spain. lgarach@ugr.es.
² Department of Construction and Project Engineering, University of Granada, Severo Ochoa s/n, Granada 18071, Spain. mlopeza@ugr.es.
³ Area of Construction Engineering, University of Córdoba, Ed. Leonardo Da Vinci, Campus Rabanales, Ctra N-IV, Km-396, Córdoba 14014, Spain. fagrela@uco.es.
⁴ Department of Construction and Project Engineering, University of Granada, Severo Ochoa s/n, Granada 18071, Spain. javiord@ugr.es.
⁵ Department of Construction and Project Engineering, University of Granada, Severo Ochoa s/n, Granada 18071, Spain. fjalegre@ugr.es.
⁶ Ministry of Development, Avda Madrid, 7, Granada 18071, Spain. jamoya@fomento.es.

Abstract

Recycled concrete aggregates and mixed recycled aggregates are specified as types of aggregates with lower densities, higher water absorption capacities, and lower mechanical strength than natural aggregates. In this paper, the mechanical behaviour and microstructural properties of natural aggregates, recycled concrete aggregates and mixed recycled aggregates were compared. Different specimens of unbound recycled mixtures demonstrated increased resistance properties. The formation of new cement hydrated particles was observed, and pozzolanic reactions were discovered by electronon microscopy in these novel materials. The properties of recycled concrete aggregates and mixed recycled aggregates suggest that these recycled materials can be used in unbound road layers to improve their mechanical behaviour in the long term.

Keywords: electronic microscopy; mechanical properties; pozzolanic reactions; recycled aggregates; self-cementing.