
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: THURSDAY, September 8, 1994                   TAG: 9409080064
SECTION: VIRGINIA                    PAGE: C-1   EDITION: METRO 
SOURCE: RAY REED
DATELINE:                                 LENGTH: Medium

ASPHALT WINS AS SMOOTHER I-81 SURFACE

Q: When Interstate 81 was built, there was a big struggle between the asphalt and concrete industries for the paving contracts. As I recall, some stretches between Roanoke and Lexington were built with one surface, and some with the other, to allow the then-Highway Department to test which held up the longest. I assume there was a winner and loser ultimately, after several winters like the one we just had. What was the outcome of the Great Paving Wars?

F.L., Roanoke

A: Some good news turned up as we looked into your question: That bumpy stretch of concrete that everybody complains about on I-81 in Botetourt County will soon get a smooth topcoat.

It's expected to be repaved with-are you ready?-asphalt.

The Department of Transportation hopes to seek bids on the job in January. It'll be spread over two years.

The topcoat is a temporary fix. ``Tractor-trailer turnpike,'' the 32 miles of I-81 from Christiansburg through Botetourt County, is under study for a six-lane rebuilding project early in the 21st century.

None of this means concrete or asphalt is the better material. The diplomats at the Department of Transportation didn't lose any time saying concrete and asphalt both have vital places in road building-depending on the region.

They did admit they won't be using those materials the same way they were applied in the early '60s, when the interstate system was built. The engineers have learned a thing or two about drainage under pavement.

The key lesson: Water in mountain clay soil pools under pavement and washes away its foundation. After several thousand truck tires pound on a surface that's no longer supported by soil, a pothole grows.

It took awhile for this action to become apparent on I-81's 141/2 miles of concrete. During the first several years, concrete appeared to need very little maintenance. Then: pothole city, and the bumpy patch jobs we now ride on.

Overall, though, the concrete was a success. Predicted to have a life of 25 years when it was put down about 1965, it has lasted almost 30.

In upkeep costs, I-81's concrete is about equal to asphalt over the same period and under similar traffic, said Allen Williams, maintenance engineer for the Salem district.

One other point: I-81's concrete isn't that bad. Just ask anyone who's driven the older interstates elsewhere.

We want to avoid insulting anyone's regional heritage, of course, but ask someone who's moved here from states with abbreviations like, ah, Pa., N.J. or N.Y.

Got a question about something that might affect other people, too? Something you've come across and wondered about? Give us a call at 981-3118. Maybe we can find the answer.

by CNB