Research On Pisha Sandstone-porous Planting Concrete Preperation And Plant Experiment

The Pisha sandstone is a kind of sedimentary rock layers with poor diagenesis,which originated in dry sub-arid regions.It will easily have slope failure problems under the erosion of wind,water and gravity,and thus causing disasters,because of it's typical constitutive property and special water sensitivity.Previous concept still mainly based on governance of the Pisha sandstone itself,ignoring the potential utilization value of it as natural resource.So it is of great importance to make use of the Pisha sandstone as resources to reduce governance cost,meanwhile,and to improve the governance efficiency.Further researches on the Pisha sandstone,in Jungar country of Erdos,using the Pisha sandstone as mineral admixtures for Portland cement and sulphoaluminate cement.The composition,microstructure and morphology of cementitious material hydration hardened products are analyzed by means of X-ray diffraction and scanning electron microscopy to investigate the effect of the Pisha sandstone on cements properties,hoping to make the most of the Pisha sandstone as mineral admixture of cement in the future,meanwhile,the properties and plant compatibility of the Pisha sandstone-porous planting concrete under the condition of it's workability are investigated.The main conclusions are as follows:?1?The addition of the Pisha sandstone with some degree have accelerating setting effects on Portland cement and sulphoaluminate cement,and would increase Standard consistency water consumption of Portland cement and sulphoaluminate cement.The addition of the Pisha sandstone would improve the compressive strength of Portland cement with some degree,and the compressive strength of sulphoaluminate cement are decreased,The release rate of Portland cement and hydration heat are decreased with the degree of the Pisha sandstone substitution,accompany with heat of hydration delay.When the mass fraction substitution of the Pisha sandstone powders is 5?,the initial setting time of Portland cement and sulphoaluminate cement are shortened by 30? and 47?,respectively,and the water requirement for normal consistency are increased by 6.6?and 21.7?,respectively.?2?The Pisha sandstone contains SiO₂.thus the hydration process of Portland cement are promoted with the degree of the Pisha sandstone substitution,meanwhile,increased thewater-cement ratio of Portland cement,result in the increase of C-S-H formation,lead to the increase of harden cement paste densities,and the decrease of holes,so the compressive strength of Portland cement increased.but are decreased with excessive substitution of the Pisha sandstone.As for sulphoaluminate cement,the bigger the proportion of Pisha sandstone was,the lower hydration process was,the addition of Pisha sandstone result in the decrease of Ca?OH?2 and C-S-H formation,the harden cement paste structure turned loose and holes increased.which lead to the decrease of the compressive strength of cement.?3?Control cement paste fluidity at 180 mm and objective void of porous concrete at 28?,combine molding technology including slurry mixing and vibrating method to prepare porous planting concrete,the results shows that the compressive strength,pore structure and permeability performance of the Pisha sandstone-porous planting concrete reach the standard of porous concrete.?4?Choose the preferably cementitious material proportion with well concrete performance to conduct vegetation experiment,mix the lou soil,nutrition soil,fertilizer and seeds with a certain proportion,then mix with water at a suitable sizing agent condition,fill the porous concrete with this sizing agent,and watered daily.It turned out that the plants grows satisfactorily well on concrete.Lolium perenne was chosen.Proved that the compatibility between porous planting concrete and plants performance well.The experiment consequences indicate that the addition of the Pisha sandstone would improve the compressive strength of Portland cement with some degree,and the release rate of Portland cement and hydration heat are decreased.So it can be considered as modified material applied to the Pisha sanstone area,and generalize the use of porous planting concrete to the soil erosion area.