Negotiations to end the costly two-week-old concrete strike in Northern Virginia collapsed yesterday, with Virginia Concrete Co. saying it had made its "final offer" and intended to begin hiring permanent replacements for striking workers if the proposal was not accepted.

The offer, including a 15 percent raise in wages over three years, was rejected unanimously by an 18-member Teamsters negotiating committee Thursday night as insufficient.

"The sticking point is money, period," said Teamsters Local 639 President Philip Feaster. "We're willing to continue talking."

"We gave the union our final offer," said Tom Wotring, a lawyer representing Virginia Concrete in the negotiations. "That means there is no more . . . . As I told them, we squeezed out every dime that we could squeeze."

Wotring said the company "will be back in business to some extent, hopefully a significant extent, some time next week." The Springfield company shut down this week after using management personnel during the first week of the strike to provide some concrete to the booming Northern Virginia construction industry.

Barring a change of heart by the union, Wotring said that the company was "going to have to find new drivers."

No new negotiations -- which have been conducted with the help of a federal mediator -- are scheduled.

The strike against Virginia Concrete, the largest supplier in the Washington area, has come at the height of the construction season.

Construction managers have begun to lay off workers and progress on scores of projects, including the Vienna Metro station, Tysons Corner office buildings and curb installation, has been delayed.

"Several contractors have said, 'You're hurting us,' " Feaster said. "And I said, 'We're not hurting you. Our people would be on those trucks if those people would give us the increase we have asked for, which we think is more than reasonable due to their . . . increase in profits over the last year.' "

About 270 drivers, mechanics and maintenance personnel went on strike May 16 over pay, pension and job security issues.

Feaster said the union wants raises of $1.50 an hour over the next three years, plus 40 cents an hour in pension contributions over the same time, for a total increase of $1.90 an hour.

The company's final offer is $1.50 an hour, which the company said workers could divide between salary and pension as they liked.

The maximum hourly wage for the striking workers is currently $10.50.

In a statement, Virginia Concrete said its offer "meets all the concerns" of the striking workers, and urged that they be permitted to vote on it. Union officials have rejected that request.