Truck drivers for Excavation Construction Inc. one of the general contractors on the Benning Road station on the Metro's Blue Line, went on strike against the large construction firm yesterday after efforts to reach a new contract agreement failed.

The drivers, members of Teamsters Local 636, threw up a picketline around the company's Bladensburg truck yard early yesterday morning. According to Teamster local president Daniel George. The union represents 80 drivers who work for the firm, said George.

The strike comes at a time when Excavation Construction Inc. is under investigation by two federal grand juries, including one probe in Baltimore which has focused on relations between the company and a former Teamster local offical.

That investigation is looking into allegetions that company officals did favors for former local president Franks DeBrouse in exchange for concessions from the union. Debrouse was ousted from the union presidency by a reform slate headed by George in June 1977.

The Teamsters contract with Excavation Construction expired April 30. Since then, according to both sides, there have been frequent meetings between union and management as the two side tried to agree on a new contract.

The main issue dividing the sides in the dispute is whether drivers should receive premium pay - time and a half - when they work on Saturdays, even if they have not already worked 40 hours that week. The previous contract provided such premium pay.

According to George, drivers low on the seniority list will frequently find they are unable to work a 40-hour week Monday through Friday because of such factors as bad weather. The drivers will then sometimes be compelled to work on Saturdays, he said.

Allen G. Siegel, an attorney who represented Excavation Contruction in contract talks, said that the company wanted to do away with the premium pay provision on certain federally regulated jobs inorder to be competitive when they bid against nonunion firms.