Concrete Pavement with a Drainable Base – Stabilization & Lifting

Problem:

Pavement system has lost foundation support. The poor and/or uneven support can result in premature cracking of the concrete, spalling or corner breaks, and settlement at the joints and dips in the pavement. Insufficient support strength may be caused by:

  • Loose or un-compacted foundation soils that were untreated prior to construction of roadway
  • Loose soil or sand in the sub-base or subgrade below the drainable base migrate into the drainable base and is carried out of the system as the water flows through the drainable base. This allows the drainable base to drop into the sub-base/subgrade, causing loss of support for the concrete pavement.

Solution:

Apply the URETEK Deep Injection Process with URETEK 486 water resistant expansive polymer injected through tubes at a typical depth of 12″ to 24″ below the drainable base to repair foundation soils and then continue injection into the soils if needed to lift the concrete pavement to grade. If DCP tests show deeper problems, additional depth(s) of injection can be added as needed. This is accomplished by drilling multiple 3/4″ holes through the concrete and injecting through tubes into the foundation soils. 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. This stabilizes the foundation soils, compressing the drainable base back up against the bottom of the pavement without filling the drainable base with polymer.

Expected Results:

  • Compact the loose foundation soils and compact the loose drainable base back up to the bottom of the concrete slabs.
  • No fouling of the drainable base with polymer – preserving the drainable base while not wasting limited maintenance money on filling the drainable base with polymer.
  • Continued injection into the soils through tubes can lift the pavement system if needed, without fouling the drainable base.

Benefits:

  • Zero daytime lane closures
  • Pavement can be lifted without the expense of filling the drainable base and without further fouling of the drainable base
  • Injection can be accomplished in wet soil conditions as the 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.
  • Injecting a concrete “mud jacking” slurry or a polymer directly under the surface of the concrete to lift the pavement will first fill the drainable base, making it impervious to water, permanently fouling the drainable base. This process will also use significant additional material to fill the drainable base before the material will begin to lift the roadway, forcing the client to pay for a negative. The concrete mud-jacking material has very little tensile strength and will not hold up to the vibration of traffic. While the polymer will certainly lock up the drainable base and has great tensile strength – the foundation soils will not be repaired.
  • Removal and Replacement of pavement, drainable base and the weak foundations soils is extremely expensive and causes significant traffic delays.