Effect of Freeze-Thaw Cycles on Performance of Stabilized Subgrade

Abstract

A comparative laboratory study was conducted to evaluate the durability of three different subgrade soils stabilized with hydrated lime, class C fly ash (CFA), and cement kiln dust (CKD). Cylindrical specimens were compacted at optimum moisture content (OMC) and cured for 7 days in a moist room having a constant temperature and controlled humidity. Selected specimens were also compacted at a higher molding moisture content of OMC+4%. After curing, the specimens were subjected to different freeze-thaw (F-T) cycles and tested for unconfined compressive strength (UCS) or resilient modulus (Mr). The UCS and Mr values after F-T cycling were compared with those of the raw soil specimens to determine the influence of soil and additive type on durability. The UCS and Mr values revealed that the addition of cementitious additive increased the durability of stabilized specimens against F-T cycles. The extent of improvement in durability, however, was dependent on the characteristics of both soil and additive and number of F-T cycles.