建渣与粉砂制备可控基坑回填材料的性能与应用

Properties and Application of Controlled Foundation Materials from Construction Waste and Pit Silt

摘要:

以济南遥墙机场改扩建施工产生的大量建筑垃圾、粉砂土为主要骨料制备了具有高流动性、自密实和高强度特点的可控低强度材料（CLSM）。试验结果表明，掺入建渣或石屑的试验组比纯粉砂的试验组强度显著提升，且强度随掺量增加而增大；建渣的改性效果比石屑高出约80%，且更为经济；最佳配合比干湿循环强度降低并稳定在1 MPa左右，质量损失率稳定在1%左右，其压缩性能与水泥掺量为6%（质量分数）的水泥土相同，干湿后压缩变形量远小于压实粉砂，满足飞行区道基的长期承载要求。

Abstract:

In order to deal with the problem of backfilling in the narrow area of the underpass in the high-load flight area， a large amount of construction waste and silt produced by the reconstruction and expansion of Jinan Yaoqiang Airport was used as the main aggregate to prepare the controlled low-strength materials（CLSM） with the characteristics of high fluidity， self-compaction， and high strength. The test results show that the strength of the test group mixed with construction waste or stone debris increases significantly compared with the only silt used. The modification effect of construction waste is about 80% higher than that of stone debris. It is more economical to add construction waste than stone debris， but not for the increase of the cement content. The dry - wet cycle strength of the best mix ratio decreases and stabilizes at about 1 MPa， with the mass loss rate stabilizing at about 1%. The compression performance is the same as soil with a 6% cement quality score， and the compressive deformation after the dry - wet cycle is much less than that of silt， which meets the long-term bearing requirements of the foundation in flight area.