Permeability properties of self-compacting concrete with coarse recycled aggregates L.A. Pereira-de-Oliveira ⇑ , M.C.S. Nepomuceno, J.P. Castro-Gomes, M.F.C. Vila University of Beira Interior – C-MADE, Centre of Materials and Building Technologies, Covilhã, Portugal highlights  Permeability properties of SCC with 20%, 40% and 100% of coarse recycled aggregates were studied.  According to the air permeability method applied, the SCC mixtures are considered airtight.  The recycled coarse aggregate incorporation did not significantly affect the water permeability.  Water capillarity coefficient is slightly decreased when 100% of coarse recycled aggregate is used.  Water penetration depth is reduced with the increasing of the recycled aggregate in SCC. article info Article history: Received 12 July 2013 Received in revised form 11 October 2013 Accepted 31 October 2013 Available online 21 November 2013 Keywords: Capillary water absorption Coarse recycled aggregate Concrete permeability Self-compacting concrete abstract This article addresses to the issue of durability related properties of self-compacting concrete (SCC) with the use of coarse recycled aggregates obtained from demolition of concrete structures. The objective was to verify the influence of recycled aggregates on SCC permeability properties. For this purpose four different types of concrete mixes were produced, one of them used as reference with natural coarse aggregates and the others prepared with 20%, 40% and 100% of recycled coarse aggregates. The properties related to the durability of SCC, as air and water permeability and capillary absorption were determined on concrete specimens with and without preconditioning. The results from fresh and hardened concrete properties lead to the conclusion that it is viable to replace natural coarse aggregates by recycled coarse aggregates since the present research does not show any detrimental to the SCC permeability properties. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction The potential use of recycled aggregates in the self-compacting concrete composition increases the ecological value and partly solves the issues of waste disposal sites generated by construction and demolition of structures. In the last two decades, the proper- ties of normal concrete with recycled aggregates were extensively studied [1–6]. From these studies it is known that, comparing with the natural aggregates, the recycled aggregates density is lower and the water absorption is higher. These differences are due to the incrustation of cement paste on the recycled aggregates sur- faces. Thus, the increased of the content of recycled aggregates in normal vibrated concrete, both coarse and fine, causes a loss of the mechanical properties. Furthermore, the coarse recycled aggre- gate shows a greater negative influence than the recycled fine aggregate [7–9]. Also the durability of the recycled aggregates con- crete can be strongly affected by the porosity and the high water absorption of the recycled aggregates [10]. The cause is usually associated to the fact that, to reach the same workability, the water demand to produce concrete with recycled aggregates is higher compared to natural aggregates, leading to the increase of the water/cement ratio, thereby, also increasing the porosity of the cementing matrix [8]. The use of water-reducing admixtures may minimize this effect, since they may provide workability to the mixture without increasing the water/cement ratio. The relatively poorer durability properties of recycled aggregates concrete can be adequately compensated by the use of fly ash, either as a replace- ment of cement or addition, in the concrete mix design [7]. When compared with normal vibrated concrete, the SCC mix- tures usually exhibit a better durability potential, even when the mixtures have larger water contents. This is due to increased fines content in SCC, that refines the microstructure and hence the pore network of the material [11]. It is the capillary porosity that greatly affects the permeability of concrete [12]. The permeability of SCC is typically lower than that of ordinary concrete. This is mostly attributed to the superior flow properties, dense microstructure and refined pore. Good flow properties result in superb packing condition due to better consolidation, and thus contribute to reduce the permeability of concrete [13]. So, the SCC mixtures 0950-0618/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.conbuildmat.2013.10.061 ⇑ Corresponding author. Tel.: +351 275329738; fax: +351 275329969. E-mail address: luiz.oliveira@ubi.pt (L.A. Pereira-de-Oliveira). Construction and Building Materials 51 (2014) 113–120 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat