Wetting-Drying Durability of Lateritic Soil Stabilized with One-Part High-Calcium Fly Ash Geopolymer

This study investigates the durability under wetting and drying conditions of marginal lateritic soil (MLS) stabilized with a one-part high-calcium fly ash geopolymer (OPFAG). The variables include an MLS: fly ash ratio of 70:30, solid sodium hydroxide content ranging from 0 to 40%, and the number of wet-dry cycles. Durability is evaluated by measuring the unconfined compressive strength (UCS) of MLS samples stabilized with OPFAG and MLS samples stabilized with ordinary Portland cement (OPC). The results show that OPFAG improved the engineering properties of MLS. The highest UCS values are achieved at 20% solid sodium hydroxide, achieving a UCS of 1889 kPa for the geopolymer-stabilized MLS and at 5% OPC for OPC-stabilized MLS (1320 kPa). The UCS of both stabilized MLS samples increases with the number of wet-dry cycles up to 6 cycles, after which a decline is observed.