Preparation Technology Of Raw Soil Wall Materials With Pouring Type

Raw soil material is a kind of building material which can be used for building construction only by simple processing without roasting.Buildings made of raw soil materials have good thermal insulation performance and can regulate indoor humidity.However,the wide use of raw soil materials is affected by the backward traditional construction technology and the defects of low strength,large shrinkage and poor water corrosion resistance.The purpose of this paper is to study pourable construction technology of raw soil wall materials and analyze the modification technology of it.It is expected that the mechanical properties,shrinkage properties,water resistance and working properties of raw earth materials will be improved.In addition,the energy consumption of the modified raw soil material during its use is simulated.Through the above research,the following experimental conclusions are obtained:1)Prepared raw soil wall material with Chongqing native raw soil material,The springing table expansion of raw soil wall materials with different liquid-solid ratios was studied,and the simulated pouring test was carried out.The results of model pouring test show that the pouring performance of the mixture is very poor when its expansion is 125 mm-145 mm,marked as L5;it is poor when its expansion is 145 mm-170 mm,marked as L4;it is good when its expansion is 170 mm-190 mm,marked as L3;it is excellent when its expansion is 190 mm-240 mm,marked as L2;it is very excellent when its expansion is greater than 240 mm,marked as L1.The spreadability of jumping table can be used to characterize the pourability of raw earth wall materials.2)In this paper,the effect of tung oil modification experiment was discussed from three aspects: physical and mechanical properties,water resistance and working performance,and the most suitable tung oil content and liquid-solid ratio were explored.The optimum tung oil modification ratio is 15% tung oil and 0.40% liquid-solid ratio.The compressive strength is 4.15 MPa,the flexural strength is 1.45 MPa and the shrinkage is 1.5%.When tung oil is emulsified by emulsifying process,raw soil material's mechanical properties can be improved by about 15% and its extension can be increased by 20 mm.Pourability up to L3.3)The optimum proportion of cement modification is 0.40% liquid-solid ratio and 7% cement content.Cement modification can make the compressive strength of raw soil material reach 3.76 MPa,the flexural strength reach 1.26 MPa,the shrinkage rate is reduced to 1%,and the expansion can be increased by 10-15 mm.When water reducer is used in the soil-cement system,the working performance of the mixture can be improved.When the cement content is 7% and the water reducer content is 1.5%,the expansion of the mixture in the experimental group with liquid-solid ratio of 0.30 can be increased from 130 mm to 178 mm.Pourability up to L3.4)Cement-tung oil composite modification can obtain pouring type raw soil wall materials with good working performance,low liquid-solid ratio and good physical and mechanical properties.The liquid-solid ratio of 0.30 composite modified raw soil material mixture's Pourability property up to L3.compressive strength increased to 6.84 MPa,flexural strength 1.64 MPa,shrinkage only 0.74%,and soaking softening coefficient 0.90 in 3 hours.5)The pouring type raw soil wall material prepared in this paper has better thermal insulation performance than rammed raw soil wall.It proves that the modified experiment does not destroy the unique thermal insulation characteristics of raw soil materials.In summary,the compressive strength of the pouring type raw soil wall material prepared in this paper can reach 6.84 MPa,the shrinkage can be controlled within 1%,the water resistance coefficient in 3 hours can reach 0.90,and the pourability can reach L3.It has better thermal insulation performance than the traditional rammed raw soi wall,and can be used as the building material of raw soil building wall in Chongqing area.