29Oct 2013

Demonstration of in-situ stabilization of soils for Pennsylvania Department of Transportation

By uretekhr

URETEK recently had the opportunity to illustrate the  in-situ stabilization of soils through injection using the URETEK 486Star structural polymer.  The demonstration was conducted for the Pennsylvania Department of Transportation at Pennsylvania State University.

First step, build the boxes.

1 - The test boxes

Each box was constructed of .75″ plywood restrained by 2″ x 2″ x .125″ angle iron and .375″ and Plexiglas inserts restrained by 2″ x 2″ x .25″ angle iron.

2 - The different grades

Next, each box was filled with various untreated soils.  The first level was 9″ of silty sub-grade mixed with RAP.  The second level was 6″ of medium sand, the third level was river run aggregate (.375″ to .75″ diameter) and the top level was 2″ of limestone aggregate.  Each soil layer was rained in from approximately 3 feet height and there was no additional compaction.

3 - Injecting STAR 486 polymer

Next, the URETEK team injected each box with approximately 150 pounds  of the URETEK 486Star 4-PCF FR.

4 - Polymer filling voids - close
In this image you can see the polymer (the yellow color on left side) actually moving into the voids.

After the boxes were saturated with the 486Star polymer, the boxes were dismantled and the plywood, Plexiglas panels and restraints were removed.

4 - Dismantling the sample's walls

What was left was a substance strong enough to withstand an ad hoc unconfirmed compressive test.  Front = 5.5″  Rear = 10″ GVW = 12,000 lbs.

6 - Demonstrating strength of STAR 486