Abstract The use of recycled aggregates in con- crete opens a whole new range of possibilities in the reuse of materials in the building industry. The utilisation of recycled aggregates is a good solu- tion to the problem of an excess of waste material, provided that the desired final product quality is reached. The studies on the use of recycled aggregates have been going on for 50 years. In fact, none of the results showed that recycled aggregates are unsuitable for structural use. However, some hypothetical problems related to durability aspects resulted in recycled aggregates being employed practically only as base filler for road construction. This paper focuses on the pos- sibility of the use of recycled aggregate concrete as a structural material. For that purpose an experi- mental study of the shear behaviour and strength of beams made with recycled aggregate concrete was studied. Twelve beam specimens with the same compression strength, four concrete mix- tures using different percentages of recycled coarse aggregates (0%, 25%, 50% and 100%) and three different transverse reinforcement arrange- ments were cast and tested up to failure. Analyt- ical predictions of the experimental results were carried out using a numerical model based on the modified compression field theory and simplified models such as those proposed by Cladera & Mari, the Canadian standard CSA and the Eurocode-2. The results obtained indicate that a substitution of less than 25% of coarse aggregate, scarcely affects the shear capacity of RC beams, provided that all measures related to dosage and durability aspects have been adopted. Keywords Recycled aggregates Æ Recycled aggregate concrete Æ Structural behaviour Æ Shear strength 1 Introduction The amount of construction and demolition waste (CDW) has increased considerably over the last few years. The recycling and the reuse of this material is necessary, considering the impact that the use of natural resources and non use of CDW is causing. This would not happen if the use of recycled material were possible. The largest CDW obtained is concrete [1, 2], and it is the most used construction material nowadays. The studies with respect to the appli- cability of recycled concrete aggregates (RCA) are extended around the world. Most research has focused basically on the mechanical properties of recycled aggregate concrete as a test element, and its real application is in road construction. How- M. Etxeberria (&) Æ A. R. Marı´ Æ E. Va ´ zquez Department of Construction Engineering, School of Civil Engineering, Universitat Polite ´ cnica de Catalunya (UPC), 08034 Barcelona, Spain e-mail: miren.etxeberria@upc.edu Materials and Structures (2007) 40:529–541 DOI 10.1617/s11527-006-9161-5 ORIGINAL ARTICLE Recycled aggregate concrete as structural material M. Etxeberria Æ A. R. Marı´ Æ E. Va ´ zquez Received: 13 July 2005 / Accepted: 15 March 2006 / Published online: 13 July 2006 Ó RILEM 2006