Loess stabilization using cement, waste phosphogypsum, fly ash and quicklime for self-compacting rammed earth construction

Loess is green building material according with contemporary call for sustainable development. This paper works on the using of cement, waste phosphogypsum, fly ash and quicklime for loess stabilization. The unconfined compressive strengths of air curing samples with different contents of the mentioned four materials were studied, respectively. An orthogonal test was used to evaluate the effects of additives on softening coefficient, flexural and compressive strength of stabilized samples with 55 degrees C curing temperature. Effects of curing temperature ranging from 15 degrees C to 85 degrees C on strength and water-resistance were investigated. And the microstructure of the samples was analyzed by SEM observation. The experimental results revealed that samples with mix proportion of 100% loess, 10% cement, 3% PG, 20% FA and 8% quicklime obtained a high compressive strength of 18.64 MPa at 3d and a softening coefficient over 0.9. Curing temperature had a significant improvement on loess stabilization. Microstructural analysis results showed the formation of ettringite and C-S-H gels in the cementitious system, which was consistent with macro-mechanical properties. (C) 2019 Elsevier Ltd. All rights reserved.