Better Roads, May 2012
Road Science
By Tom Kuennen, Contributing Editor
Portland cement concrete (PCC) is the most widely used structural material in transportation infrastructure, and it’s widely used for pavements as well. But the control of freshly mixed PCC properties is essential to ensure workability during placement, and compressive strength and long-term durability. Not unlike modifiers in bituminous pavements (see Asphalt a la Carte: Modifiers Control Mix Performance, April 2012, pgs. 16-27), mineral and chemical concrete admixtures work both physically and chemically to improve the durability and quality of portland cement concrete, boost or retard set time, increase resistance to frost, sulfate attack and alkali-silica reactivity, and improve placement.