GCL hydration by lateritic soils under isothermal and heating/cooling cycles

Recent work has shown that GCL hydration by subgrade is influenced by a series of variables related to GCL characteristics, as well as subgrade initial moisture content, particle size and mineralogy. Another major variable is the effect of GCL exposure to daily thermal cycles during the landfill construction phase. Additionally, tropical climate conditions, such as in Brazil, result in the occurrence of lateritic fine soils, which present high moisture content and a particular mineralogy. The present study evaluated the GCL hydration by two lateritic subgrades (clay and clayey sand) under isothermal conditions and heating/cooling cycles. The isothermal analysis confirmed the influence of subgrade initial moisture content on GCL hydration since both soils with the highest moisture content showed 50% higher GCL hydration. GCL samples exposed to heating and cooling presented poor hydration, even at a higher subgrade moisture content, confirming the influence of thermal conditions on GCL hydration and properties. In comparison with studies of literature, lateritic soils showed higher GCL hydration speed than soils formed in temperate climates.