Long term behavior of a pulverized fly ash grouted sand

摘要

A laboratory investigation was conducted in order to develop a new grout based on pulverized fly ash. Pulverization of a selected Greek fly ash yielded a gradation with D_(15)=1.3#mu#m, D_(50)=6#mu#m and D_(85)=20#mu#m and Blaine specific surface equal to 8300 cm~2/gr. Suspensions of pulverized fly ash were injected into clean sands and the grouted specimens were tested in triaxial compression and permeability. Grouted specimens were tested in triaxial compression after curing periods of 28 days and70 months, in order to evaluate the long term behavior of grouted sand. The coefficient of permeability of the sands is improved by 4 to 7 orders of magnitude. The Mohr-Coulomb failure criterion represents the behavior of grouted sands. The cohesion values of grouted sands range from 280 kPa to 450 kPa after 28 days of curing and increase by 30 percent, on the average, when the curing period is extended to 70 months.