关键词: 重塑石灰土, 强度再生, 红黏土, 微观形貌

Abstract: There are large amounts of crushed lime stabilized soils after the rebuilding of engineering projects which are constructed with limed soils many years ago. It’s necessary to reuse them to avoid environmental pollution and to save construction investment. But the strength of crushed lime soil would significantly reduce. So, the gel materials are added to enhance the mechanical properties of crushed lime soil. The remolded lime soil is re-stabilized through adding 5% lime or cement. Comparisons of strength and compressibility between the lime re-stabilized soil and cement re-stabilized soil are made. The results show that the mechanical properties of lime re-stabilized soil are better than those of cement re-stabilized soil. Furthermore, it reveals the internal mechanism of superior performance for lime re-stabilized soil with particle size analysis, scanning electron microscope, X-Ray diffraction and thermo gravimetric analysis tests. It is found that the lime and limed-aggregates in lime re-stabilized soil can be cemented up well. But cement fails to form effective cementation with limed-aggregates. The cement re-stabilized soil forms edge-plane and edge-edge contact porous structure. The Calcium hydroxide remained in the remolded lime soil is the major factor which makes the property of cement re-stabilized soil inferior to the lime re-stabilized soil.

Key words: remolded lime soil, strength recovered, laterite soil, microtopography