Cement Stabilized Soil Field Samples: Quality Control for Bases and Sub-bases

Quality control assessment of cemented pavement layers typically involves extracting cores and subjecting them to unconfined compression tests. This research focuses on evaluating the applicability of the porosity/cement (η/C_iv) index in field pavement projects. The study investigates wetting–drying accumulated loss of mass and unconfined compression tests on soil–cement cores that were mixed, compacted, and cured in field layers. The field layers consist of a sand-Portland cement blends with varying dry unit weights (18.5 kN/m³ and 19.5 kN/m³) and cement contents (3%, 5%, and 7%). These results are then compared with laboratory samples of similar characteristics. The findings reveal, for the first time, that the η/C_iv index is a suitable parameter for assessing both durability and strength of compacted sand-Portland cement layers in the field. Furthermore, the study highlights that durability tests are less sensitive to sample extraction procedures compared to unconfined compression tests. Consequently, there is a risk of inadequate representation of the true field performance of cemented-stabilized materials when using unconfined compression tests on small diameter core samples.