Mechanical, durability, and thermal performance of bio-stabilized compressed earth blocks for sustainable housing

Affordable and sustainable building materials are urgently needed to address housing shortages in developing nations. Compressed earth blocks (CEBs) are a promising alternative to conventional masonry, yet their mechanical strength and durability remain limiting factors. This study proposes a bio-based stabilization strategy incorporating starch biopolymer (STB, 2–6%) as a binder, wheat husk ash (WHA, 1–3%) as a pozzolanic filler, and NaOH-treated jute fibre (JF, 0.3–0.9%) as reinforcement into sand–clay CEBs. After 56 days of curing, compressive strength increased from 0.41 MPa (untreated) to 4.03 MPa with 4% STB, representing an ∼881% improvement. The addition of 2% WHA further enhanced strength to 4.1 MPa, while incorporation of 0.6% JF raised it to 4.29 MPa, an overall increase of ∼928% compared with untreated blocks. Indirect tensile strength rose from 0.11 MPa to 0.43 MPa (∼289% gain). According to the findings, durability is enhanced in terms of short-term resistance to Freeze–Thaw (F-T) deterioration, with strength loss under 12 F–T cycles reduced from 37% (untreated) to