Lime Stabilized Rammed Earth – Influence of Curing and Drying Conditions

In this project, the use of excavation soil for the construction of noise barriers made of rammed earth (RE) is investigated. In its natural form, RE has poor durability when exposed to harsh Danish weather conditions, and one of the most common ways to improve the durability of earth-based construction materials is through stabilization with inorganic binders such as lime. Some of the precautionary measures one needs to take when stabilizing soil with lime is the suitability of the soil and the importance of proper curing before the material is exposed to drying. Unstabilized RE (USRE) specimens, as well as lime stabilized RE (LSRE) specimens with 5% lime are produced and exposed to different combinations of curing and drying before testing the unconfined compressive strength (UCS). The results show that the USRE specimens obtain the highest UCS in the dry condition but completely eroded in the wet condition. On the other hand, little to no erosion took place for the LSRE specimens and a UCS could be obtained in the wet condition. An additional curing time of 14–91 d prior to drying the RE specimens results in an increase in UCS, but the influence is highly dependent on the temperature. An increase in the temperature from 23 ℃ to 40 ℃ results in a higher increase in UCS than increasing the curing time from 0 d to 91 d for specimens cured and dried at 23 ℃.