Valorization of seashell by-products in pervious concrete pavers Dang Hanh Nguyen a,b , Mohamed Boutouil a , Nassim Sebaibi a,⇑ , Lydia Leleyter b , Fabienne Baraud b a Ecole Supérieure d’Ingénieurs des Travaux de la Construction de Caen (ESITC-Caen), 1, rue Pierre et Marie Curie, 14610 Epron, France b Normandie Univ., France, UCBN UR ABTE EA 4651, QALEA, F-14032 Caen, France highlights  Seashell By-Products (SBP) size highly influences the granular arrangement of matrix.  The SBP can effectively replace gravel 2/6 mm for pervious concrete pavers.  SBP 2/4 mm provides a good compromise for the overall composition of the matrix.  SBP 4/6.3 mm decrease in mechanical strength and promoting the water infiltration.  The compaction pressure into a single layer of 7.4 kPa is optimal with good strength. article info Article history: Received 29 May 2013 Received in revised form 8 August 2013 Accepted 12 August 2013 Keywords: Valorization Seashell by-products Pervious concrete pavers Permeability abstract Seashell By-Products (SBP) are produced in an important quantity in France and are considered as waste. This paper studies their use as a partial replacement of aggregates in pervious concrete pavers considered as an environmentally friendly building material. After designing the control pervious concrete pavers by investigating the energy and the pressure compaction, the coarse aggregate fraction were partially (20% or 40% by mass) replaced by SBP obtained from the Crepidula shell. The crushed Crepidula seashell of 2/ 4 mm and 4/6.3 mm were used to make new seashell by-products based pavers. In this paper, the mechanical and hydrologic properties of both pervious concrete pavers were determined. Results show that the seashell by-products have the potential to be used as aggregate. The mix design allows achieving both a compressive strength of 16 and 15 MPa for respectively the control pervious concrete pavers and the seashell by-products based pavers and a permeability coefficient in the range of 3–8 mm s 1 . Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction According to the French Union of Aggregate Producers [1], in France, almost 400 million tons of aggregates are consumed each year, i.e. 6 tons per inhabitant. However, most of the aggregates used are natural aggregates which are usually excavated from river beds, quarries, dredged from sand or shingle banks under the sea. In order to reduce the environmental impact of building materials and specially natural resource consumption, the reuse of waste and by-products is one of the solutions. For aggregates, many studies [2–6] have been carried out to investigate the replacement of nat- ural aggregates in concrete by recycled aggregates, slag aggregates, and recently seashells. Regarding the seashells, it was reported [4–6] that they are a hard material that can produce good quality concrete, however, a higher cement content may be required. Moreover, due to the angularity of the shells, additional cement paste is required to ob- tain the desired workability. Aggregate containing complete shells (uncrushed) should be avoided as their presence may result in voids in the concrete and lower the compressive strength. In Europe, France has an important fishing and shellfish farming industry that produces nearly 200,000 tons of shells from shellfish breeding and nearly 50,000 tons of shellfish per year from fishing [7]. These activities generate thousands of tons of seashell by- products (empty shells) to be discharged, as they are considered as waste. For the moment, some attempts has been made in France to recycle them as soil conditioner [8] or animals food [9] but none of these attempts gave satisfaction in terms of viable and added va- lue recycling. In this study, Seashell By-Products (SBP) from the French west coast were prepared and used to partially replace natural aggre- gates to make a specific concrete: pervious concrete pavers. Pervi- ous concrete is an environmentally friendly material and an effective means to meet growing environmental demands. Pervi- ous concrete is used to prevent from flooding during heavy rain and to increase the water infiltration into the soil [10,11]. Pervious concrete uses the same materials as conventional con- crete, with the exceptions that the fine aggregate is nearly or en- tirely eliminated, and the size distribution of the coarse 0950-0618/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.conbuildmat.2013.08.017 ⇑ Corresponding author. Tel.: +33 2 31 46 23 00; fax: +33 2 31 43 89 74. E-mail address: ec.ecomateriaux@esitc-caen.fr (N. Sebaibi). Construction and Building Materials 49 (2013) 151–160 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat