Study on Performance of Foamed Cement Soil for Backfill Preparation by Site Excavation
In order to improve the utilisation of excavated soil in urban underground space,experiments were conducted to investigate the effects of foam content and soil content on the backfill properties of excavated soil foam concrete.The results show that the prepared foam concrete not only meets the requirements of general urban underground space for backfill performance,but also meets the requirements of general natural foundation for bearing capacity.Increasing the foam content can significantly improve the fluidity of the excavated soil foam concrete and reduce its wet density.Increasing the soil content will lead to a decrease in the working performance.The unconfined compressive strength of excavated soil foam concrete decreases with the increase of foam content and soil content.The thermal conductivity decreases with the increase of foam content and increases with the increase of soil content,mainly because the introduction of foam will reduce the density,while the increase of soil content will reduce the density.When the foam content is less than or equal to 0.4m3,the water resistance coefficient of the excavated soil remains above 0.9,and when the foam content exceeds 0.4m3,the water resistance coefficient is significantly reduced.Increasing the soil content will slightly reduce the water resistance.When the soil content exceeds 40％,the water resistance can still meet the requirements in the specification.Therefore,in practical engineering applications,in order to improve the utilization rate of excavated soil as much as possible,the soil content should be as high as 40％,but the foam content should not exceed 0.4m3.
万方数据
维普
