Properties of Stabilised Compressed Earth Blocks Using Lime and Cement for Low-Cost Housing in Adamawa State

This study evaluates the properties of stabilised compressed earth blocks (CEBs) produced using local earth materials from Adamawa State, North East Nigeria, with cement and lime as stabilising agents. The housing deficit in Nigeria's North East geopolitical zone is severe, and CEBs offer a cost-effective, locally sourced building material with a lower embodied carbon footprint than fired bricks or cement blocks. Earth material is collected from three sites in Yola, Gombi, and Song Local Government Areas and characterised by Atterberg limits, Proctor compaction, and particle size distribution. Stabilisation is conducted at cement contents of 5, 8, and 10 percent, lime contents of 4 and 6 percent, and binary combinations of cement and lime. Blocks are produced by static compression at 10 MPa and cured for 28 days under moist conditions. Unconfined compressive strength, wet compressive strength, water absorption, and erosion resistance (spray test) are evaluated. Results indicate that 8 percent cement-stabilised blocks satisfy NIS 369 minimum dry compressive strength of 2.0 MPa and meet erosion resistance requirements. Binary combinations of 6 percent cement and 4 percent lime provide a 15 percent cost reduction while maintaining performance. Blocks from Yola source material consistently outperform other locations due to higher clay mineral content. Keywords: compressed earth blocks, stabilisation, low-cost housing, Adamawa State, lime.