Construction use of abandoned soils

Abstract

Taiwan is a county under rapid development. Excavation in thousands of construction sites generated a huge amount of soils. In many cases, the soils are disposed randomly such that they are termed abandoned soils. A comprehensive study was conducted to investigate for reuse options of these soils: sub-grade construction, cement block production, structural concrete production, and asphalt concrete production. Five soils, representing predominant soil types in Taiwan were selected in this study. The compaction test results demonstrated that all five soils were suitable for subgrade construction. The compression tests for cement mortar showed that all soils produced mixes with strengths higher then 3.45 MPa and may be used to make cement blocks. The compressive strength test results of soil concrete samples showed that all soils except for the mix having 100% of soil No. 5 produced strengths higher than 17.25 MPa. The wet/dry durability test showed that the pozzolanic action of the soil concrete samples continued beyond 28 days and there seemed to be no detrimental effects. A comprehensive mix design was performed for each soil type and also developed a control mixture to test the use of abandoned soils in hot mix asphalt concrete. The study demonstrated that with proper design even clayey soils can be used to produce construction materials.