The company also moved to play down speculation that it was lining up a bid for Blue Circle Industries, Britain's leading cement maker, in the wake of last week's ground-breaking deal between RMC Group and Rugby Group.
Hanson bought BR DeWitt Inc, a New York state-based aggregates, asphalt and ready-mixed concrete producer, and Superior Products Co, a concrete- pipe maker with operations in Cleveland and Philadelphia. A breakdown of the price paid for each business was not disclosed.
"These transactions continue our successful strategy of building up our business through bolt-on acquisitions and capital expenditure," Andrew Dougal, Hanson's chief executive, said. "We have spent approximately pounds 275m on acquisitions in the US this year, out of a total spend of approximately pounds 380m."
More US acquisitions were expected in the coming months.
On possible moves in Britain, Justin Read, a Hanson spokesman, said: "It's life as usual. We don't think anything has changed."
Last week, RMC, Britain's leading producer of ready-mixed concrete, agreed to pay about pounds 920m for Rugby, the country's third-largest supplier of cement.
The advent of substantial vertical integration across the building materials industry - cement is concrete's costliest ingredient - triggered talk that Hanson may launch a copycat move for Blue Circle. Hanson is the country's fourth-largest supplier of concrete, and the second largest producer ofaggregates.
Hanson shares shed 14p yesterday to close at 479p, while Blue Circle backtracked 9.75p to finish at 320p. Blue Circle shares dropped to 269.5p in late October, a near 12-month low, after it issued a profits warning, citing difficulties in emerging markets.