Photo Courtesy: NCFI Ployurethanes
As part of the New Jersey Turnpike Authority’s (NJTA) $1 Billion Capital Projects Campaign “to boost mobility and improve safety for generations to come,” box culverts
are suddenly big business.
“Most people take them for granted,” says Douglas Laubshire Sr., a partner with Expert
Concrete Restoration and Repair (ECRR), a waterproof and repair contractor in Tri-State area.
“These concrete structures are everywhere, especially in areas with bodies of water, moving
water, high rainfall, and where roadways pass over those water bodies. They allow for creeks to
flow under roadways, water passages to be maintained between bodies of water, and provide
support for roadways. You don’t notice them until they fail and the road sinks or is flooded.”
If a culvert shows signs of failure, and the vital structures they support are at risk DOTs
swing into action. When the NJTA’s maintenance contractor discovered trouble with a culvert in
Woodbridge, NJ they called in Laubshire’s company, ECRR.
Laubshire explains, “A section of the turnpike was sinking around a box culvert, so we
got the call to inspect it, determine if it might be the cause, and present a repair solution. The
18-foot-long concrete box culvert was experiencing severe soil infiltration. As happens with
concrete, cracks appear over time along the walls and were allowing water and the support soils
around the culvert and underneath the roadway to seep in. There was significant soil loss, and
the soil beneath the roadway had weakened and was causing it to settle.”
To repair the culvert, ECRR used an innovative geotechnical polyurethane product
called Terra-Lok by the U.S company NCFI Polyurethanes.
Josh Burcaw, EVP of NCFI Polyurethanes’ Geotechnical Division, says, “Remediating
soil loss around culverts is a twofold problem. First, the voids and cracks must be fully sealed to
prevent future intrusion into the culvert. The second issue is to rehabilitate the weak soils
around the culvert and below the roadway, or whatever structure is being supported to
reestablish the soil and culvert’s load-bearing capacity. Terra-Lok, does both in a single
Terra-Lok is a single-component polyurethane system formulated for permeating loose
soils and filling voids, making it ideal for culvert rehabilitation. When injected into the soil at
depth, Terra-Lok permeates the area in a gooey liquid state allowing for full saturation of the soil
and the filling of any voids, gaps, pockets, or seams. Terra-Lok reacts to exposure to the
moisture content of the soil, expands up to 25 times its initial liquid volume, then cures in place
to become monolithic. The result is a densified soil base with void areas filled, including cracks,
crevices, and separated joints.
The culvert was 16-feet below the surface, so ECRR had to inject Terr-Lok on a two-foot
grid pattern at eight-foot depths, for full soil permeation to stabilize the culvert, roadway, and soil
According to Laubshire, “It took us three days to install, and when we finished, the
polymer had sealed the cracks around the perimeter of the culvert and stabilized the soil. The
project was a complete success and helped the NJTA avoid weeks of repairs and delays, and
saved tens of thousands of dollars with alternative methods.”
NCFI Polyurethanes got its start in 1964 and manufactures polyurethane foam systems for
spray foam insulation (SPF), geotechnical, agricultural, SPF roofing, marine flotation,
aerospace, molding, and many other uses. The company also offers a complete line of flexible
foams for furniture, transportation, bedding, carpet underlay, and packaging. NCFI also has
manufacturing plants in NC, GA, and TX. NCFI belongs to the Barnhardt Manufacturing
Company, Inc. family of companies. To learn more about NCFI please visit www.NCFI.com.