Laboratory improvement of clay mineralogical and swelling properties using hydraulic binder treatment

This article outlines the findings from experimental research to improve the mechanical characteristics, notably the swelling potential of a clay sourced from the Boumagueur area in eastern Algeria. In a first part, oedometer tests conducted according to ASTM 4546-03, revealed that increasing binder content significantly reduced swelling properties. From the natural state (without hydraulic binder) to 9% binder content, swelling pressure decreased by 72% for samples treated with lime, 58% for cement, and 62% for the lime-cement mixture. Similarly, swelling potential was notably reduced, with lime treated samples showing an 87% decrease, compared to 57% for cement and 73% for the lime-cement mixture. In the second part of this work, X-ray diffraction analysis confirmed that the reduction in swelling was due to the formation of a cementitious phase, such as hydrated calcium silicate (CSH). Overall, the addition of hydraulic binders effectively improved the swelling behavior of the soil.