Stabilization of the swelling soil for earth construction

This study is concerned with the method of cast earth as part of an investigation series on earth construction. The effect of two clay swelling inhibitors; polyethylene glycol [PEG] and of carboxymethyl cellulose [CMC] on the swelling of a clay-bearing soil are studied to enable the stabilization of the soil with CEM I 42.5 N. The soil composed of 14% clay, quartz, and calcite, is stabilized with 10% cement. 3% polycarboxylate superplasticizer is added relative to the mass of the cement, to gain the soil pourable properties. The results show that the PEG and CMC clay-swelling inhibitors reduce the expansion of the soil by ~30 and ~40% and lead to a maximum increase of 24 and 46% in the 90-day compressive strength respectively. The interactions between clay, cement, and swelling inhibitors are discussed. The findings allow advantageous applications for producing building units for construction purposes in desert areas.