Abstract:

In the excavation process of foundation pit, a large amount of muck is generated. In order to minimize the influence of muck accumulation and transportation generated by foundation pit excavation, the technology of manufacturing unfired bricks by foundation pit muck should be developed. Hence, the proportioning test on unfired bricks with silty clay as main raw material, cement as cementing material, and fine sand as grading reinforcing material is designed by uniform test method based on a test area of Hangzhou Metro Line 10. Through linear regression and singlefactor analysis of test results, the influence of various factors on the water resistance and compressive strength of the samples are investigated. The results show that: (1) The softening coefficient of unfired brick prepared by foundation pit muck in silty clay stratum increases with the rise of cement and fine sand proportion. (2) The 7day and 28day compressive strengths increase with the rise of cement proportion and decrease with the rise of straw fiber proportion. When the better material ratio is adopted, the softening coefficient of unfired bricks is greater than 0.8, the 7day and 28day compressive strengths are greater than 10 MPa.

Key words: silty clay, foundation pit muck, recycling, unfired brick, proportioning design