Optimization in recipe design of interlocking compressed earth blocks by incorporating fine recycled concrete aggregate

Abstract

Interlocking Compressed Earth Blocks (ICEBs) have recently surfaced as a valuable and innovative inclusion among earthen building materials. They offer workable answers to the common problems with burned bricks and cement blocks. Researchers frequently used river sand in their studies to address and reduce the finer content in soil. This study explored recipes to make ICEBs from construction and demolition wastes. Fine recycled concrete aggregate (FRCA) was used as a soil modification within the ICEBs as a part of this investigation to support eco-friendly, low-carbon product development driven by global climate concerns and the need for improved construction waste management to combat pollution. ICEBs, made by mixing construction and demolition trash, regulate environmental impact and address the scarcity of building materials. Due to the inherent diversity of soil and the lack of a standardized mix design for the manufacturing of ICEB, 40 different mix ratios were generated using the proportionated blends of sand and FRCA. Based on the compressive strength results, the best recipes representing conventional river sand and the FRCA were selected. The prepared samples of ICEBs using the optimized mix recipes of river sand and FRCA were further analyzed for mechanical, thermal, and durability performance alongside the required forensic endorsements, and the test results were enhanced for both ICEBs compared to first-class burnt clay bricks. Sand-incorporated ICEBs achieved 13.72 MPa compressive strength, while FRCA-incorporated ICEBs reached 13.38 MPa. Both ICEBs showed a noticeable improvement in compressive strength compared to various studies. The durability of ICEBs, in terms of water absorption, improved around 70% compared to fired bricks commonly used in the construction industry. The test findings reveal that FRCA incorporated ICEBs showed 14.3% lower thermal conductivity than ICEBs with sand incorporation. Therefore, the use of ICEBs specially designed with FRCA provides the most sustainable alternative to conventional fired bricks used by the construction sector in the developing countries.