PROBLEM

Stabilization of areas of roadways where full depth repair is to be done to minimize the need for additional cutout of poor base/sub-base/sub-grade once the roadway surface has been removed.  The failure of the pavement surface is often caused by weak or insufficient support in the foundation soils.  Ignoring this problem leads to premature failure of the patched pavement.  Tearing out the base/sub-base/sub-grade is costly and causes significant lane closure time including daytime lane closures.  The replacement of the foundation soils is often ineffective due to the inherent difficulty to compact the new soils in a small area.  Adjacent panels can be negatively affected by disturbing their foundation soils during the repair.

SOLUTION

Utilize URETEK Deep Injection process to stabilize the foundation soils prior to replacement of the failed pavement section.  This is accomplished by drilling multiple 3/4″ holes through the existing pavement and injecting polymer through tubes, placed at minus 3′ to minus 4′ from the pavement surface.  This is usually done on a 4′ grid pattern.  URETEK monitors the surface using laser monitors and/or dial indicators and knows that the roadway has become adequately supported when an indication of movement is detected on the monitors.  Injection is also performed one row in front and in back of the failed section.  The pavement can then be removed, and new pavement placed on a sufficiently strong base/sub-base.

EXPECTED RESULTS

  • Foundation soils are sufficiently stiffened to support the load on the new patch.
  • Extends the life of the full-depth patch.

BENEFITS

  • Zero daytime lane closures.
  • Injection is accomplished sufficiently ahead of the patching crew so that the patching process can take full advantage of the lane closure time frame.
  • Injection can be accomplished in wet soil conditions as URETEK 486 STAR® hydro-insensitive polymer will form a dimensionally stabile polymer even when injecting into saturated soils. The expansion process will also drive the water out of the soil system.
  • No disruption to utilities.