Page 221 - New Trends in Eco efficient and Recycled Concrete

Recycled mollusc shells
8

Caroline Martı´nez-Garcı´a, Bele ´n Gonza ´lez-Fonteboa, Diego Carro-Lo ´pez
and Fernando Martı´nez-Abella
Civil Engineering School (Escuela de Ingenieros de Caminos, Canales y Puertos),
˜
˜
University of A Coruna, Coruna, Spain

8.1 Introduction

In order to promote the sustainability of concrete, efforts have been made to incor-
porate by-products and wastes from different industries as alternatives in natural
materials used in the mix proportions. That is the case of natural aggregates being
replaced with many different by-products. Seashell waste, such as oyster shells,
mussel shells, and scallop shells, is available in huge quantities in certain regions
and is usually dumped in landfills.
In fact, bivalve molluscs represent almost 10% of the world’s total fishery pro-
duction, being 26% of the entire volume and 14% of the entire value of the world’s
total aquaculture production. In fact global bivalve mollusc production (capture
plus aquaculture) has increased substantially in the past 60 years, going from nearly
1 million tonnes in 1950 to about 14.6 million tonnes in 2015 (FAO, 2015). By spe-
cies, bivalve mollusc production via aquaculture in 2015 consisted of 38% clams,
cockles and ark shells, 35% oysters, 14% mussels and 13% scallops and pectens
(FAO, 2018).
China is by far the leading producer of bivalve molluscs, with 10.35 million
tonnes in 2015, representing 70.8% of global molluscan shellfish production and
80% of global bivalve mollusc aquaculture production, as all of the Chinese bivalve
production is cultured. Japan is the second largest producer, far behind China with
a production in 2010 of approximately 819,131 tonnes, followed by the United
States (676,755 tonnes), the Republic of Korea (418,608 tonnes), Thailand
(285,625 tonnes), France (216,811 tonnes) and Spain (206,003 tonnes). Other main
bivalve-producing countries are Canada, Chile, Italy and New Zealand (FAO,
2018).
The production of these large quantities of molluscs represents an important eco-
nomic activity for several countries. The consumption of these products varies in
terms of type of mollusc, but around 10% of molluscs are destined to the cannery
industry. This represents the focal point of the production of mollusc shells and
makes it easier to recycle the mollusc shell as concrete aggregates (Martı ´nez-Garcı ´a
et al., 2017).

New Trends in Eco-efficient and Recycled Concrete. DOI: https://doi.org/10.1016/B978-0-08-102480-5.00008-7
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