Recycling Construction Waste to Improve Soil-Cement Mixes for Stronger, Eco-Friendly Building Blocks

What is it about?

The research explored the use of mixed recycled aggregate (MRA) with specific granulometry in combinations with soil-cement mixtures to investigate their physical-mechanical properties. The methodology employed a two-level factorial experimental design to evaluate varying ratios of MRA to soil (1.00, 1.67, and 2.33) and different cement content levels (10% to 14%). The study identified that the optimal mixture contained 60.2% MRA, 25.8% soil (MRA/soil ratio of 2.33), and 14% cement, resulting in a compressive strength of 3.4 MPa and water absorption of 18.1%. A multiple regression model predicted that a mixture with an MRA/soil ratio of 1.71 and 10.22% cement could achieve the minimum required compressive strength of 2.1 MPa with water absorption below 22%. The findings suggest that the inclusion of construction and demolition waste (CDW) in soil-cement blocks could enhance recyclability and sustainability. The study also emphasizes the necessity of correcting clay soils to improve the performance of soil-cement mixtures.

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Photo by Trương Tuyết Ly on Unsplash

Photo by Trương Tuyết Ly on Unsplash

Why is it important?

This study is important as it addresses the significant environmental impact of the construction industry by proposing the incorporation of construction and demolition waste (CDW) into soil-cement mixtures. By doing so, the research contributes to reducing natural resource consumption and waste generation, which are major concerns in construction. This approach promotes sustainability by utilizing recycled materials in building, potentially lowering carbon emissions and minimizing energy usage compared to conventional materials. The study's findings offer a scalable solution for enhancing the recyclability of CDW, aligning with global efforts towards eco-friendly construction practices. Key Takeaways: 1. Optimal Mixture Composition: The study identifies that incorporating 60.2% mixed recycled aggregate (MRA) with 25.8% soil and 14% cement results in a compressive strength of 3.4 MPa and water absorption of 18.1%, indicating a viable mixture for soil-cement blocks. 2. Predictive Modeling: Using multiple regression models, the research predicts that a mixture with an MRA/soil ratio of 1.71 and 10.22% cement can achieve the necessary compressive strength while keeping water absorption below 22%, showcasing the potential for tailored soil-cement formulations. 3. Enhancing Soil-Cement Performance: The study highlights the importance of particle size correction in improving the compressive strength and stability of soil-cement mixtures, emphasizing the role of granulometric composition in developing sustainable building materials.