I-66 Annular Space Grouting

Haymarket, Virginia

The Job

During the widening of Interstate 66 near the interchange with US-15, nine new culverts were installed by jack and bore, and one via direct jacking. The carrier pipes were a mix of spiral metal, precast concrete, and corrugated HDPE, and ranged in length from 150 to 350 feet.

The Challenge

The contractor, who was responsible for grouting, was concerned about carrier pipe buoyancy during grouting, and also run length. All work had to be done from one side of the interstate highway (three lanes in each direction, plus full-width shoulders and a median strip), as there was no access on the far side.

The Solution

CJGeo proposed 30lb/cuft cellular concrete for the annular space grouting. Cellular concrete is the preferred material for annular space grouting because it is highly flowable, and reduces the chances of damage to carrier pipes in long placements. Its low unit weight also reduces carrier pipe buoyancy. CJGeo placed 350CY of cellular concrete to successfully complete the jack and bore annular space grouting over three different mobilizations.