National Concrete Pavement Technology Center

Project description

Concrete for pavements must be proportioned so that the concrete is economical and durable. Because ordinary Portland cement (OPC) is the most costly component and is generally less durable than the aggregates, the OPC should be minimized. OPC significantly contributes to CO2 during manufacturing. Therefore, minimizing the OPC will also make the concrete greener. This research developed a mixture proportioning method to minimize the OPC content. This is achieved by characterizing the aggregates that will be use in the concrete to minimize the voids in the aggregates (fine and coarse). This will result in lower OPC requirements. This research assessed concretes proportioned with the new method. All concretes met edge slump and surface void requirements. All concretes met compressive and flexural strength requirements. Most concretes met formation factor requirements. Select testing indicates that shrinkage, as measured with shrinkage rings, is likely dependent on paste content; lower paste contents lead to lower shrinkage, but more research is needed. Select concretes did not perform well in freeze-thaw testing, however void spacing and size were not assessed.