A Smoother Ride For North Freeway Commuters
by: Gail Delaughter, October 31, 2011 3:10:00 pm
"This section of I-45 experiences up to 290,000 vehicles per day. That includes both directions, northbound and southbound."
TxDot Assistant Area Engineer Henry Quiroga has been overseeing the resurfacing project. A little over a mile of roadway was resurfaced from north of the 610 Loop to just north of Tidwell, .
"The existing roadway was exhibiting a lot of cracking, potholes, and it was requiring maintenance on a more regular basis than desired."
Quiroga lays out small samples of asphalt on the hood of his truck to explain the three layer process that transformed the bumpy roadway into a smooth, glasslike surface. First, crews milled out four inches of the existing road bed. They then put down a hot asphalt rubberized surface, designed to seal the road bed from water. On top of that layer goes a fine mix of asphalt.
"The rich bottom layer, or RBL, is intended to actually move and flex with the roadway. Since it is a concrete sub-surface it's going to tend to crack, so this is intended to try to deter the cracking for as long as possible."
The final layer is a coarse two-inch asphalt mixture, and Quiroga says the layers are designed to work together to handle the heavy volume of traffic, especially trucks. And he says the smoothness of the roadway is gauged throughout the process. One of the things they look at is bumps per mile.
"We offer an incentive and a disincentive to the contractor. If he achieves good to excellent ride quality, this contractor stands to make up to $15,000 in bonus."
The project costs one-point-nine million dollars and was completed in about two weeks. Quiroga says like any road surface, potholes and cracks will develop over time. But he says their intent is to lengthen the amount of time between repairs, and that will mean fewer detours for drivers.