Lime Stabilised Glacial Till Clay Incorperating Wheat Straw or Waste Tyre Rubber Granules

This chapter reports the potential of using Lime for the Stabilisation of Glacial Till Clay (GTC) incorporating Wheat Straw (WS) or Waste Tyre Rubber Granules (WTRG). WS is a readily available agricultural waste that is left over after the harvesting of the wheat grains. WTRG is a waste product obtained from shredding scrap tyres into a fine powdery material. In order to assess and understanding the strength variations caused by the addition of WS or WTRG and lime into the glacial till, thirteen mixes were designed at various GTC content with up to 3% WS or WTRG replacement levels, where 2% lime was used as stabiliser. Compacted cylindrical test specimens (50 mm diameter and 100 mm long) were used. Compressive strength tests were carried out after 7, 14, 28 and 56 days of curing. The results showed that the strength of the stabilised test specimens were predominantly improved by the addition of lime, although, higher WS or WTRG dosages resulted in a reduction in strength. A dosage of 1% WS-lime stabilised clay provided a slightly higher strength gain of 2.65 N/mm2 for the 56-day strength, compared to the control mix with no WS (2.5 N/mm2). The 1% WTRG –lime-stabilised clay also resulted to a high strength value of 2.6 N/mm2. Overall, the results suggest that it is possible to stabilise clay soil using lime based systems incorporating WS or WTRG for use as Improved filling material in road building or as a subgrade material or for unfired brick making.