Curing time impact on flexural properties of alkali activated clayey soil with and without Polypropylene fiber reinforcement

Soil remediation is one of well-known methods used in construction engineering to treat problematic soil. Alkali activator such as Potassium hydroxide has been known for its activation of amorphous aluminum silicate occurring in fly ash. This when added to soft soil results in cemented material with strength properties resembles that of cement. However, the failure mode observed is very brittle making the application of such technique very limited to specific engineering applications. To extend the use of alkali activation method in the field of construction engineering soil reinforcement using polypropylene fibers has been recentlyadapted. One of engineering properties in assessing resistance against horizontal displacement is flexural strength towards bending. In this regard alkali activated soft soil with Potassium hydroxide and reinforced with polypropylene fibers was subjected to two different curing regimes namely 28 and 90 days. The flexural tests revealed greater impact on flexural properties for both alkali and alkali reinforced specimen due to prolonged curing regime of 90 days when comparing with that of specimen cured for 28 days. Keywords: Soil stabilization; Polypropylene fibers; Alkali activation; flexural strength; Curing regime.