The study investigates recycling organic waste in Algeria due to the rising use of natural resources and energy in concrete production and the large amount of organic waste discarded. The aim is to use compost as a partial replacement for sand, reducing the use of natural aggregates in the concrete industry while also reusing previously discarded waste as part of a circular economy. An experimental study was carried out on concrete’s thermal and mechanical properties to determine the effect of partial compost replacement on these properties. Five mixtures were created by replacing sand with compost in different proportions: 0, 5, 10, 15, and 20%. Slump and density were assessed in the formulations’ original state. Mechanical tests were performed on the hardened concrete to determine porosity, compressive strength, and flexural strength. Thermal tests were also conducted on various types of concrete to determine thermal conductivity. The findings show that the texture of the compost reduced the slump, highlighting the importance of incorporating an admixture to achieve the desired workability. While meeting normal-weight concrete standards, concrete density was reduced. The mechanical properties of concrete with small amounts of compost were similar to regular concrete; instead, waste porosity improved insulation.
Purpose of study: The interest of this study is to show that the composting of various organic materials makes it possible to contribute to reducing the quantities of Waste sent to landfills and, consequently, the removal of their environmental impact. The aim is to show that aerobic composting of organic Waste can be an alternative to sustainable waste management in Algeria by examining the potential for producing compost from different organic waste streams.
Methodology: The method is based on analyzing documentary data, field surveys and experiments. The latter examines the potential for producing compost from different organic waste streams in Algeria. Three types of Waste are composted and analyzed: green Waste, kitchen waste and a combination. The experiment was carried out from March until June 2021; it involved using organic Waste to produce three different composts in their composition. Research has focused on studying the complex interplay between physical, chemical and biological factors that occur during composting and compost quality parameters.
Result: The results showed that composting the organic fraction of Waste reduced its mass by 22% for green Waste, 70% for kitchen waste and 63% for the mixture of the two. The variation of the process monitoring parameters (temperature, humidity, pH) corresponds perfectly to those established in previous studies. Through analysis and the germination test, the result has made it possible to obtain good-quality compost that can be used in agriculture.
Conclusion: The maturity of the composts obtained was checked by the germination test, demonstrating that the highest germination rate was recorded at the level of the soil-compost mixtures, regardless of the type of compost used. However, compost made from kitchen scraps alone has the highest rate. Chemical analyses of the composts confirmed these results, which are acceptable to French standards, given the lack of Algerian standards. This study demonstrates that composting has significantly reduced the Waste mass and obtained good quality compost.