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Since their appearance in the 1950s, compressed earth blocks, a modern form of adobe brick have increasingly been studied for their many advantages compared to earlier forms of earthen materials. Their mechanical and thermal improvement is one of the main interests of many researchers. This study investigates the mechanical and thermal behavior of compressed earth blocks (CEB) loaded with crushed mussel shells (CMS) and stabilized with Portland cement. Two series of mixtures were prepared for CEB manufacturing using various CMS contents (0%, 5%, 10% and 15%), then compacted with a static load. Series 1 CEB without cement; Series 2 CEB with cement. Using X-ray diffraction, the mineralogical composition of soil and CMS was established. A scanning electron microscopy (SEM) examination of the mussel shell's morphology was performed too. The compressive and tensile strengths for both series were assessed after two different curing times (14, 28 days). The thermal conductivity of manufactured blocks was evaluated using the hot-disk method. The findings revealed that the increase in CMS content (from 0% to 15%) led to a reduction of the compressive strength by 35% for non-stabilized CEB and by 53% for stabilized CEB. However, the obtained compressive strengths remain above the minimum required compressive strength (𝜎𝑐 > 1 𝑀𝑃𝑎). In contrast, the thermal performances of both series were significantly enhanced. When increasing the CMS content (from 0% to 15%), the thermal conductivity decreases by 13% for non-stabilized CEB and decreases by 17% for stabilized blocks. The findings presented in this paper suggest that mussel shell aggregates are a feasible option to improve thermal behavior of compressed earth blocks.

Background: The management of marine waste is a major concern in several countries. Recycling shell waste in concrete formulations may be one of the alternatives for producing sustainable materials at a lower cost. Objective: In this research paper, the performance of ground mussel waste for non-structural concrete formulation has been investigated. Methods: Two alternatives were explored in this research. The first aimed at incorporating treated Mussel Powder (MP) for partial substitution of cement (6, 12, and 24% by weight). The second aimed to investigate the feasibility of using MP as an additive with a proportion of 3, 6, 9 and 12% by weight of cement. Physico-mechanical properties of advanced composites have been studied in both fresh and hardened state through several laboratory tests. Results: The test results indicated that the inclusion of the MP allowed the formulation of concretes with normal density and lower air content. The mechanical behavior was characterized using new formulas adapted to the newly formulated concretes. Based on the obtained results, the treated MP could be used as a cement substitute with a proportion up to 12% or as a mineral additive with a percentage of 3% to produce a non-structural concrete that meets the normative requirements in terms of compressive and tensile strength. Conclusion: The recycling of mussel waste in concrete will contribute to the preservation of the environment by reducing the quantity of shellfish waste. The concept of “green” concrete can be achieved through the use of the formulated concretes in the paving works or as a blinding concrete.

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