Compressed Earth Blocks Using Sediments and Alkali-Activated Byproducts

Fouad Belayali,Walid Maherzi,Nor-Edine Abriak,Ahmed Senouci,Mahfoud Benzerzour

doi:10.3390/su14063158

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.

Highlights

IntroductionToday, saving natural resources and combating climate change are two major challenges faced by our planet to ensure good living conditions for mankind in the future
Today, saving natural resources and combating climate change are two major challenges faced by our planet to ensure good living conditions for mankind in the future.Natural resources, such as fossil fuels, are not renewable
The objective of this paper is to study the physical and mechanical behavior of compressed earth blocks using the sediment in the raw state as sand and to analyze its microstructure

Summary

Introduction

Today, saving natural resources and combating climate change are two major challenges faced by our planet to ensure good living conditions for mankind in the future. Natural resources, such as fossil fuels, are not renewable. Pierrehumbert et al [1] have reported that the carbon dioxide emissions in the atmosphere through activities, such as fossil fuel burning, cement production, and deforestation, need to be reduced to zero. The lack of progress towards the reduction of carbon dioxide emissions has created justifiable panic about the world climate. The use of sediments in building materials can save natural resources and promote a disposal solution that does not disturb the ecosystem. In France, approximately 50 million m3 of sediments are dredged, stored, treated, or transported abroad each year, compared to 300 million m3 in Europe [2] and nearly 300 million m3 in the United States

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