الفهرس 
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Abstract
Abstract
The present thesis is devoted to study the properties and the behavior of a stabilized soil using the cast earth technology, within the context of earth construction. The soil is stabilized with Portland cement as well as with cement replacement materials. The superplasticizers are added to the mix to enhance the fluidity necessary for casting the soil. The interaction between the binders and the superplasticizers is studied.
Another goal for the thesis is to avoid the negative effect of the clays present in the soil which hinders the casting procedure. It is concerned with treating the clay-bearing soil with suitable reagents to attain the required flowability.
The thesis is composed of two parts:
1) The first part deals with investigating the compatibility between the superplasticizers and the binders used to stabilize the soil.
2) The second part deals with investigating and improving the casting behavior a chosen clay-bearing stabilized soil.
In the first part, the compatibility between four polynaphthalene sulfonates (PNS) and four polycarboxylates (PC) superplasticizers with three cement systems; a) CEM I 42.5 N, b) its mix with 25% cement kiln dust as well as c) its mix with 25% glass powder, is studied. The compatibility issue is followed up with infrared spectra and NMR spectroscopy. These methods give data on the purity, polymerization properties and charge density of the superplasticizers.
The polycarboxylate superplasticizers are found to be more effective than the polycondensates. The greater the purity of the admixture and the higher polymerization degree lead to a better compatibility between the superplasticizer and the binder. Cement dust improves the fluidity of the mix and glass powder hinders it.
It was not possible to cast soil with 14% clay and stabilized with 10% binders in the presence of superplasticizer. The casting procedure of the same soil was, however, successful after treating the soil with the following clay-swelling inhibitor reagents; 1) 1% polyethylene glycol (PEG) or 2) 2% carboxymethyl cellulose (CMC). These reagents reduce the swelling properties of the clay and render the stabilized soil well castable with the superplasticizers.
The treated soil showed low expansion capacity (” ” " ~ " ” ”30 – 40%) and moderate 90-day compressive strength values (” ” " ~ " ” ”4 N/mm2).