Effect of the interaction between calcium sulphate and mineral additives on shear strength parameters of clayey soils

Journal of Engineering Research

Khelifa Harichane¹  Hamid Gadouri² 

[1] Chlef University;Medea University

关键词: Calcium sulphate;    Clayey soils;    Lime (L);    Natural pozzolana (NP);    Shear strength;   

DOI  :  

学科分类：社会科学、人文和艺术（综合）

来源: Kuwait University * Academic Publication Council

【 摘 要 】

In Algeria, inappropriate soils with high plasticity and low bearing capacity are commonly encountered, it was therefore necessary to improve these soils using mineral additives in order to make them acceptable for construction. However, various forms of deterioration have been observed in construction projects due to the presence of sulphates responsible on the formation of new expansive phrases such as ettringite. For this raison, an experimental investigation was undertaken to study the effect of the presence of calcium sulphate (CaSO 4 .2H 2 O) on the behaviour of the shear strength of two clayey soils stabilized with lime (L), natural pozzolana (NP) and their combination. The mechanical property investigated is the shear strength on samples cured for 7 to 120 days. In addition, X-ray diffraction (XRD) test was conducted in order to investigate the mineralogical changes of both clayey soils. The results show that both clayey soils samples without CaSO 4 .2H 2 O can be successfully stabilized with L or with a combination of lime-natural pozzolana (L-NP) which substantially increases their shear strength and produces high values of shear parameters. However, when combining a fraction of CaSO 4 .2H 2 O to samples containing L alone or a combination of L-NP, a further increase in shear strength values is obtained. In addition, higher shear parameters values are recorded. The increase in strength values is attributed to the formation of ettringite which is observed in XRD diagrams. In general, the chemical stabilization of soils depends on the calcium sulphate content, the additive type and its content, the curing period and the mineralogical composition of soil.

【 授权许可】

Unknown