EFFECT OF AGING ON THE PENETRATION RESISTANCE OF SANDS

The main objective of this study was to understand the effect of aging on the penetration resistance of freshly deposited sands. Two types o f sand, locally available river sand used as masonry sand and Beaufort Sea sand, were selected for the study. The sands were allowed to age under a constant stress of 100 kPa in a specially designed apparatus i n a dry state, as well. as submerged in distilled water and in simulat ed sea water. Penetration resistance of the sand beds was measured per iodically by pushing 4 probes into the sand bed. Mineralogical and fab ric studies on freshly deposited and aged sand samples were conducted to detect the effect of aging, if any, on sand grains. The results ind icate that aging significantly increases the penetration resistance of sands. The rate of increase in penetration resistance was higher for the submerged sand as compared with the dry sand. The increase in pene tration resistance of the sand in a dry state was attributed to rearra ngement of sand grains. In the submerged state, besides the rearrangem ent of sand particles, partial cementation caused by precipitation of salts and probably also silica on the sand grains and in the pores res ulted in the larger increase in the penetration resistance.