Hundreds of cement-truck drivers went on strike days before the Fourth of July holiday weekend, disrupting some of the largest construction projects in the city including the World Trade Center site.

More than 400 drivers for Local 282 of the International Brotherhood of Teamsters walked out of talks with the Association of New York City Concrete Producers after the union’s contract expired at 12:01 a.m. yesterday.

The local’s lead attorney, Bruce Levine, said the union had negotiated for weeks with the concrete makers.

“Local 282 fully intends to continue negotiating in good faith and looks forward to reaching an equitable resolution to this dispute so that its members can return to work as soon as possible,” Levine said.

The treasurer of the association, Joseph Greco Jr., told The New York Times in today’s editions that the union has said it would not restart negotiations until next week. A call to Mr. Greco today wasn’t immediately returned.

The union representing 3,200 crane and heavy equipment operators also went on a weeklong strike a year ago on July 1, stalling work at the trade center site and 1,000 other projects just before a holiday weekend.

The strike affects any construction site in the city working with concrete, including the trade center site, where a 1,776-foot skyscraper, September 11, 2001 memorial, and transit hub are being built. Other projects affected by the strike include new stadiums under construction for the Yankees and the Mets and several condominium projects.

Each construction site has separate schedules for pouring concrete and it wasn’t immediately clear how many sites were affected.