Study On The New Raw Soil Materials

Raw soil material general reference those without roasting,only after simple treatment of undisturbed soil materials. In addition to make the best use of local material, raw soil material has excellent thermal stability and thermal insulation performance, so it can create a suitable residential environment and application environment for mankind. In addition, raw soil material has humidity conditioning property、breathable、fire protectioning property、low energy consumption and cost cheap, what is more, it can return to the natural environment after service period.However, the traditional raw soil materials has a serious of defects, such as poor strength 、 large volume deformation and low water resistance, when earthquake is coming the raw soil buildings will be very dangerous. Right now, it greatly hindered the improvement of raw soil material construction quality because people are lack of sufficient scientific cognition about the property of raw soil materials. China, with a vast territory, rich in raw soil resources, to developed high strength、good stability and water resistance is significant for green building with comfortable and low energy consumption.The research object of this article is the new raw soil materials which used the expansive soil as the main raw materials, steel slag and a few additives as the modifying agent, curing in room temperature after compaction molding. In this paper,we discuss the relationship between strength、softening coefficient on different ages、frost resistance 、 dry-wet circulation resistance properties on 60 days and the composition of modified admixtures、the content、preparation conditions. In addition,we test the coefficient of thermal conductivity of new raw soil material. In order to explore the formation mechanism of the new raw soil materials, we try to find out the mineral composition by X-ray diffraction(XRD) analysis of the new raw soil material. We get the following conclusion.(1) It can easily developed new raw soil material with high strength and good water stability by using the modified admixture.(2) The strength of the new raw soil material developed relative slowly and the early strength is low. But it can develop a long time. The highest comprehensive strength can reach to 8.78 Mpa at 60 days, in addition, it has excellent frost resistance and dry-wet circulation resistance, the softening coefficient is ranks between 0.6 to0.8.(3) As the modifying agent content increased, the optimal water content of the new raw soil material will be increase accordingly, at the same time the strength of the new raw soil material、water saturated strength and softening coefficient increased too,in addition, the frost resistance and water resistance will also be getting better and better. It shows that when the modifying agent content is 20% and 25%, the strength of the raw soil material is more than 7.5 Mpa, the BDR is less than 40%, the softening coefficient is more than 70% in the optimum moisture content and maximum dry density, which means that it can be used as a new type of green building materials.