Compressed Earth Blocks Using Sediments and Alkali-Activated Byproducts

Abstract

Sediment dredging is necessary and vital to preserve maritime activities and prevent floods. The management of these sediments represent an environmental challenge for many countries all over the world. This study focuses on evaluating the feasibility of using dredged sediments for the manufacturing of compressed earth blocks (CEB). The alternative construction material has the potential of reducing the need for dredged sediment onshore storage or ocean dumping. Several experimental tests have been conducted on two geopolymer types, which were obtained by mixing sediments from the northern region of France, fly ash (FA), and grounded blast furnace slag (GBFS). The geopolymers, which were activated using an eight-molar concentrated sodium hydroxide solution (NH), were cured at a temperature of 50 °C. The results have shown that a geopolymer content of 36% of FA and 10% of GBFS along with (NH) alkaline solution has significantly improved the mechanical properties of CEBs, which have outperformed those of Portland Cement-stabilized traditional blocks. The use of NH has resulted in the formation of crystalline calcium silicate hydrate (C-S-H) amorphous gel. Adding GBFS to the mix has enhanced the geopolymer paste compressive strength and microstructure because of the formation of additional C-S-H. The valorization of dredged sediments in CEB based on geopolymer stabilization can contribute to the reduction of the CO2 footprint of the construction industry.

Building a Sustainable Future from Theory to Practice: A Comprehensive PRISMA-Guided Assessment of Compressed Stabilized Earth Blocks (CSEB) for Construction Applications

“…Similar results were reported by [38,42,54,57]. Reference [29] used fly ash with ground blasted furnace slag to stabilize soil blocks and found that the 28-day compressive strength was significantly greater than that of the preceding studies. The CSEB displayed a compressive strength of 16.53 MPa.…”

“…The CSEB displayed a compressive strength of 16.53 MPa. This is linked to the formation of hydrated calcium alumina silicate coexisting with geopolymer gels to form a vast, three-dimensional array of aluminosilicate [29].…”