Final report

Florida. Dept. of Transportation

PDF

Two distinct but related issues of importance to FDOT were investigated: (1) the possible impact of

recycled concrete aggregate (RCA) used as road base on the subsurface environment and (2) the

management of concrete grinding residuals (CGR) resulting from grooving and grinding operations for

Portland cement concrete pavements. Results from the literature and from testing on Florida-specific

RCA indicate that the leachate produced by the contact of water with RCA is elevated in pH. Several

factors were demonstrated to reduce leachate pH in the environment, but the extent to which this

reduction will occur depends on environmental conditions that require additional testing to evaluate.

CGR produced from concrete grinding operations is not hazardous waste, but is elevated in pH and

requires appropriate management. Best management practices should be implemented for CGR, and

examples of such practices are available. Management of CGR with concrete truck washout is a viable

option. If CGR is discharged adjacent to roadways, care must be taken to avoid impact on ecosystems.

US Transportation Collection

BDV31-977-48