PA Turnpike Undersealing
The Job
As part of a 24 lane mile mill & pave rehabilitation on the Pennsylvania Turnpike, slab stabilization was required. The Turnpike’s specification for stabilization is either liquid asphalt or polyurethane.
The Challenge
In order to keep MOT in place continuously, work had to be done 24 hours per day. Due to work on three bridges within the repair area, undersealing also had to be phased.
CJGeo’s Solution
CJGeo proposed undersealing with CJGrout 40NHL, a 4.0 lb/cuft free rise polyurethane grout formulated specifically for undersealing thick pavements in transportation environments. 40NHL is hydroinsensitive, so performs well in wet environments, as confirmed with NYSDOT GTP-9 testing.
Using a double gang drill and single grout truck, CJGeo crews undersealed up to 1.8 lane miles per shift. Drilling was completed at night, and grouting during the day, to allow the general contractor to keep MOT in place continuously.
Bridge Approach Polymer Grouting
The Job:
The George Washington Memorial Parkway connects Washington, DC with Fairfax and Alexandria Counties in Virginia. Originally designed as a scenic route, the road has transformed into a heavily used commuter route in and out of Washington. The road runs along the Potomac River, with bridges crossing deep ravines, including Windy Run.
Challenge:
Martins Construction reached out to CJGeo two weeks prior to required mobilization. The project was an accelerated deck replacement and structural repair, and loose soils on both approaches required stabilization using compaction grouting in a manor which would not affect return to service or the bridge deck overlay work.
CJGeo’s Solution:CJGeo proposed polyurethane compaction grouting using CJGrout 30NHL, which is specifically formulated for improving the bearing capacity of loose soils. Grouting was performed on 4’ centers, at 5’, 10’ & 15’ below grade, until surface movement was detected. Top-down grouting was used to help ensure maximum densification of underlying soils, and approximately 25,000 pounds of grout were used over two mobilizations. Due to polyurethane grout’s nearly immediate cure, CJGeo helped ensure that ground improvement stayed out of the critical path of this accelerated project. Pre and post grouting DCP testing was performed by Schnabel Engineering to quantify the soil density improvement.
CJGeo proposed polyurethane compaction grouting using CJGrout 30NHL, which is specifically formulated for improving the bearing capacity of loose soils. Grouting was performed on 4’ centers, at 5’, 10’ & 15’ below grade, until surface movement was detected. Top-down grouting was used to help ensure maximum densification of underlying soils, and approximately 25,000 pounds of grout were used over two mobilizations. Due to polyurethane grout’s nearly immediate cure, CJGeo helped ensure that ground improvement stayed out of the critical path of this accelerated project. Pre and post grouting DCP testing was performed by Schnabel Engineering to quantify the soil density improvement.
