01044083

Component

Hydraulic properties of the polymer-enhanced bentonite-sand mixtures (PEBSMs) investigated in this study consisted of the water retention behavior (the soil-water characteristic curve (SWCC)) and the saturated and unsaturated coefficients of permeability. The SWCCs of the compacted polymer-enhanced bentonite-sand mixtures were measured using two techniques; namely, axis-translation technique and vapor equilibrium technique. The results obtained from both methods were combined to establish a single SWCC for each specimen. The study revealed that the wetting curves for the PEBSM and clay are above the drying curves. This fact is thought to be due to the specimens being not saturated before starting the drying tests. Since the specimens are of expensive soils therefore, such a trend can be expected. The net of polymer and bentonite clusters are considered to retard the flow of water during the direct measurement. However, the net of polymer and bentonite clusters are compressed during loading and rebound during unloading. Hysteresis effect was found for the PEBSMs in the permeability versus degree of saturation curve. It is due to possible difference in the spatial distribution of water in the specimens depending whether the specimens were on drying or wetting path.

01042056

07-1092

English

21p

2007

Transportation Research Board 86th Annual Meeting

CD-ROM

Figures; Photos; References (11) ; Tables (3)

Bentonite; Hydraulic properties; Loading and unloading; Mixtures; Polymers; Soil water; Wetting and drying tests

Flow capacity (Water flow); Hot water and sand mixture; Retention; Soil water characteristic curve

Geotechnology; Highways; I41: General Soil Surveys

Transportation Research Board Annual Meeting 2007 Paper #07-1092

TRIS, TRB

Feb 8 2007 5:42PM