Effects of Delay Time on Compaction and Strength Properties of Stabilized Granular Soil

Abstract

Weak and marginal soils are conventionally stabilized with chemical stabilizers like lime and cement. During construction, sometimes inevitable delays occur between mixing of stabilizer with the soil and compaction, which have adverse effects on the geoengineering properties of the stabilized soil structures. The present study emphasizes the effects of delay time on compaction and strength properties of a granular soil stabilized with three different stabilizers, i.e. lime, cement and slag-based geopolymers. In this study, these three different stabilizers were added with soil in different proportions varying from 0 to 15% of the dry soil, and the effect of time lag was studied individually. The optimum moisture contents (OMC) and maximum dry densities (MDD) of these mixtures were determined after a time lag of 0, 3, 6, 12, 24, 48, 72 and 168 h. Further, cylindrical specimens of size 36 mm diameter and 72 mm length were prepared for all these mixes compacted to MDD at OMC taking into the effects of delay. Before conducting the UCS test, these specimens were cured at an average temperature of 30 °C for 0, 7 and 28 days in closed secure environment for assuring the prevention of moisture loss while curing. It was observed that the delay time significantly affects the OMC and MDD of mixes, and it is more noticeable in case of cement and geopolymer binders than the lime. Similarly, delay time affects the strength of cement and geopolymer stabilized mixes more adversely than lime stabilized mixes.