Terracon was retained by the Airport Development Group for a series of apron expansions at the Stennis International Airport, which began in 2012. Terracon has performed special inspections during construction on the North, South and Middle Apron expansions. Terracon performed earthwork observation & testing, which included proofrolling of subgrades, field testing to determine in-place density, moisture content and compaction and laboratory testing. Terracon has also performed cast-in-place concrete sampling and testing, asphaltic concrete testing including coring, and oversight, and concrete beam flexural strength testing. All procedures are performed in accordance with ASTM D 1557 and ASTM D 6938.