Recycling of Clay Sediments for Geopolymer Binder Production. A New Perspective for Reservoir Management in the Framework of Italian Legislation: The Occhito Reservoir Case Study

Abstract

Reservoir silting is an unavoidable issue. It is estimated that in Italy, the potential rate of silting-up in large reservoirs ranges from 0.1% to 1% in the presence of wooded river basins and intensive agricultural land use, respectively. In medium and small-sized reservoirs, these values vary between 0.3% and 2%. Considering both the types of reservoirs, the annual average loss of storage capacity would be of about 1.59%. In this paper, a management strategy aimed at sediment productive reuse is presented. Particularly, the main engineering outcomes of an extensive experimental program on geopolymer binder synthesis is reported. The case study deals with Occhito reservoir, located in Southern Italy. Clay sediments coming from this silted-up artificial lake were characterized, calcined and activated, by means of a wide set of alkaline activating solutions. The results showed the feasibility of this recovery process, optimizing a few chemical parameters. The possible reuse in building material production (binders, precast concrete, bricks, etc.) represents a relevant sustainable alternative to landfill and other more consolidated practices.

Preparation, structure and properties of hybrid materials based on geopolymers and polysiloxanes

“…A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 6 In particular, the synthetic approach developed by us [23][24][25] is used to obtain, for the first time, novel geopolymer-based hybrid materials starting from an aluminosilicate source (i.e. metakaolin, MK) a silicate solution and a low-cost commercial oligomeric siloxane mixture.…”

Thermally treated clay sediments as geopolymer source material

“…Among the recycling possibilities, applications as raw materials in the manufacture of artificial aggregate, bricks and cement clinker have recently been studied (Bernardo et al, 2000;Chiang et al, 2008;Huang, 2011a, 2011b;Tang et al, 2011). The use of clay sediments for the manufacture of geopolymer-based materials can be an interesting alternative to disposal (Chen et al, 2009;Ferone et al, 2013a;Molino et al, 2014).…”

Mechanical and thermal properties of lightweight geopolymer composites

“…Several strategies have been proposed for reducing the embedded CO 2 in the built environment [32][33]. Geopolymers are innovative binders that have been extensively researched in recent years consisting of amorphous aluminosilicates that are synthesized using alkaline activation of solid precursors such as fly ash [34][35][36], calcined clays [37][38][39][40] and blast furnace slag [41][42][43]. Geopolymers are a potential alternative to traditional Portland cement in selected applications, because they combine reduced environmental impact with excellent mechanical properties.…”