Why does concrete ride so much differently than asphalt?

State highways administrator Pericles Manthos says it's not just because they're two different materials, but because the materials and methods of applying them have improved.

"You have two schools, one that likes concrete because it's long-lasting, and one that likes asphalt because it's easier to apply and repair," said Manthos.

"That section of H-1 was poured quite a while ago, when they were still pouring concrete in sections and leveling them with flat wooden screeds. Newer sections, like the current widening in Aiea, uses more sophisticated techniques, slip-forms that are ground down to make them more level."

Laying concrete is like laying bricks; the bucking motion comes from the subtle difference between the level middles of the sections and the slight angles of the joints. Laying asphalt is a more organic process; it smooshes out like pudding and forms a continuous layer that behaves more like a liquid than a solid.

Asphalt is also more porous and rain falling upon it tends to percolate away. Not so with concrete, which is why concrete road sections generally have traction grooves combed in with diamond-bladed saws.

Concrete is springier as well. Elevated sections, such as those on H-3, are actually bowed upward in the middle. This "deflection" is designed to level out under the concrete's weight and the weight of average traffic.

"When we measure the sprung beams on H-3 to see how they're doing, we can't have cars travelling on them, because the roadway actually bounces up and down like a rubber band," said Manthos.

Williams concert cancelled

Teenie Beanies at auction

Beginning today, a complete set of Ty Teenie Beanie Babies will be available through an auction benefitting Ronald McDonald House Charities-Hawaii. Log on to the KHNL website at http://www.khnl.com or call KSSK 973-5745 for more information.

Twelve new Teenie Beanies are being offered with Happy Meals, or $1.69 with the purchase of any regularly priced McDonald's item through June 3. From June 4 to 17, four Teenie Beanie International Bears will be sold for $2.49 each, while supplies last, with the purchase of any regularly priced menu item.

Shop for a job at Expo

Job recruiters and workshops will be held to assist participants in writing resumes, preparing for the interview, job training, searching for jobs on the Internet, and exploring "hidden" job markets. Admission is $2.

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