DENVER — Summit Materials Inc. (NYSE: SUM) is acquiring companies in Denver and Arkansas for a combined $110 million. Denver-based Summit, one of the nation's fastest-growing construction-materials companies, said in a filing with the U.S. Securities and Exchange Commission that it has signed definitive agreements to purchase Everist Materials LLC of Denver and Razorback Concrete Co. of Arkansas. Everist is an aggregates, ready-mix concrete and asphalt company, and Razorback is an aggregates and ready-mix company, with collectively more than 100 million tons of permitted reserves. Both transactions are expected to close on or before Feb. 28, 2017. Summit filed with the SEC to sell 10…