Box Culvert Leak Sealing

Box culvert leak sealing using polyurethane grouting.

Challenge:

As part of an interchange upgrade, a new double box culvert was constructed.  After the new box culvert was commissioned, the original single  box culvert needed to be abandoned in place.  Access to the box culvert was only available from one end, and there were multiple sources of active water infiltration into the box culvert.

Constraints: 

The customer wanted lump sum pricing, so all sources of infiltration (potential leaks during grouting) had to be completely sealed prior to abandonment material placement.  More than 10 water infiltration/potential cellular concrete exfiltration locations were identified.  

Due to the length of the culvert (350 feet), the material used for abandonment needed to be easily pumped up to 450 feet.  Due to site constraints, material needed to be pumped 100 feet to reach the open end of the box culvert.

Solution:

Plural component polyurethane grouting was selected by CJGeo for sealing all potential cellular concrete exfiltrations. Sites included RCP pipes terminating in stone beds, a 48″ HDPE culvert extension punched through the walls of the box culvert, and multiple holes in the ceiling covered with steel plates.  Given the lump sump nature of the contract, and the exceptional flowability of cellular concrete, the culvert had to be completely watertight.  

Some of the infiltration points were actively leaking water, so the selected material had to set in, and stop active water flows.  

Result:

A CJGeo polyurethane grouting crew sealed all of the leaks in the structure.  Work was completed prior to setting the injection pipes for the cellular concrete.  The cost of sealing the leaks in the culvert to make it watertight were significantly less than the potential losses due to leaks during grouting.