Evaluation of Pervious Concrete Workability Using Gyratory Compaction

Portland cement pervious concrete (PCPC) is increasingly used across the United States, and this has prompted various entities to begin the process of developing standardized test techniques. A major issue with placing PCPC is the inconsistencies in concrete workability between mixtures developed in the laboratory and in the field. It is therefore urgent to properly determine workability of pervious concrete and to ensure that the designed concrete mixtures are suitable for particular compaction methods and field conditions. This paper describes a new test method for characterizing PCPC workability-the gyratory compaction test method. A modified Superpave gyratory compactor (SGC) is employed in the present study. Two PCPC workability parameters are defined from the gyration compaction curve: (1) workability energy index, which describes initial concrete workability and (2) compaction densification index, which describes the resistance of the tested mixture to further compaction. The effects of binder content and water-to-cement ratio as well as effect of concrete mixing time on PCPC workability are studied. Based on the test results, values of the workability parameters for concrete with various degrees of workability are specified.