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 of stabilized soil structures sometimes inevitable delays occurs between mixing the additive with the soil and compaction, which have adverse effect on the geoengineering properties of the stabilized structures. The present study emphases on 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. The granular soil is mixed with 2.5, 5, 7.5, 10, and 15% of lime and cement and 5,10,15% of slag based geopolymer by dry weight of the soil. The optimum moisture contents (OMC) and maximum dry densities (MDD) of these mixes were determined after delay periods of 0, 3, 6, 12, 24, 48, 72, 168 hours. As well, cylindrical specimens of size 36mm diameter and 72mm lengths were prepared for all these mixes compacted to MDD at OMC taking into the effects of delay. These specimens were cured at an average temperature of 300 C for 0, 7, and 28 days in closed secure environment for assuring the prevention of moisture loss while curing, after that the unconfined compressive strength (UCS) were determined. It is observed that from the test results the OMC and MDD of mixes are effected by the delay time and it is more understandable for cement and geopolymer binders than the lime. Similarly, delay time effects the strength of cement and geopolymer stabilized mixes more adversely than lime stabilized mixes