Exploring the Strength Properties and Buoyancy of Self-compacting Ultra-Lightweight Foamed Concrete Utilizing Recycled LECA

In response to contemporary needs, the construction sector is directing its attention towards sustainable alternatives to traditional concrete. Lightweight concrete is gaining prominence as a practical choice to fulfill structural, economic, and environmental criteria. The primary objective of this study was to manufacture pontoons (Dimensions: 300 mm × 300 mm × 50 mm) utilizing recycled materials, including lightweight expanded clay aggregate (LECA) balls (0, 5, 10, 15, and 20%), with the capacity to float on water. Additionally, the research sought to determine the optimal concrete material mixing ratio, focusing on both strength characteristics and buoyancy performance. In this study, 30 samples for the cube test and an additional 5 for the ultra-lightweight foam concrete (ULFC) pontoon analysis to fulfill the study’s objectives. Testing of lightweight concrete cube specimens took place on the 7th and 28th days following the curing period. Furthermore, the buoyancy test for the pontoon concrete was conducted on the 28th day. The test results reveal that the concrete mix with the highest average compressive strength is ULFC-L0, yielding 3.75 N/mm2. From the result, the ULWFC-L20 mixture exhibited a favorable result by substantially enhancing its load capacity to withstand the highest buoyancy force, reaching a value of 21.2 N. Hence, the primary discovery of this study is that the integration of environmentally friendly LECA aggregate has enhanced the buoyancy capacity of ULFC. This development offers a promising alternative for advanced applications in the coastal and offshore marine structures sector.