STATE OF NORTH CAROLINA DEPARTMENT OF TRANSPORTATION
ROY COOPER J. ERIC BOYETTE
GOVERNOR SECRETARY
DATE: July 20, 2020
TO: Division Engineers
FROM: Todd W. Whittington, PE State Materials Engineer
SUBJECT: Modifications to Table 1000-1 – Slump Requirements for Concrete
To improve workability, finishing, and concrete consolidation in structures with congested steel designs, the allowable slump for Class AA, A, B, and lightweight concrete has been increased to allow up to 6 inches. The additional slump must be achieved by adding a chemical admixture conforming to Section 1024-3.
As prescribed in Note A of the table, in no case shall the water-cement ratio on the approved concrete mix design be exceeded. Concrete exhibiting segregation and/or excessive bleeding will be rejected. Utilizing an admixture to modify slump does not relinquish the contractor’s responsibility to ensure the final product quality and overall configuration meets design specifications. Caution should be taken when placing these modified mixes on steep grades to prevent unintended changes to the set slope.
This change will take effect immediately for all contracts. The Standard Specifications and all associated manuals and references have been modified to reflect these changes. To view the official announcement, click here. For your information, a copy of the special provision SP10 R01, Table 1000-1 is linked below:
If you have any questions, please contact Brian Hunter at 919-329-4030 or bhunter@ncdot.gov.
