Recyclability of Soils Stabilised with Natural Hydraulic Lime for Earthen Constructions
摘要
The construction sector has a significant impact on the environment through greenhouse gas emissions, energy consumption, resource depletion and waste generation. In response, earth is increasingly recognised as a sustainable construction material due to its abundance, local availability, non-toxicity, and excellent hygroscopic properties. While research on earthen materials has underscored its environmental and thermo-hygrometric benefits, the recyclability of earth, particularly when stabilised with mineral binders, remains poorly understood. Stabilised soils are frequently regarded as less recyclable, yet their actual reuse potential has been scarcely investigated. This research investigates the recyclability of lime-stabilised soils, focusing on two soil types with different grain sizes. Two recycling methods were evaluated: recycling the stabilised soil without further modification and applying additional stabilisation in each cycle. These methods were tested for three recycling cycles to evaluate the behaviour of the material and performance over time. The change in aggregate size after each cycle, compressive strength and water absorption by capillarity were studied. The study found that additional stabilisation must be applied for recycling without downcycling previously stabilised soils. The results show that if the same amount of lime is applied at each cycle, the strength increases exponentially. Due to the irreversible nature of mineral stabilisation, it is recommended to use cementitious stabilisers only when necessary.