Certification of Standard Reference Material 114r Portland cement

Abstract

The SRM 114 series for portland cement fineness has been provided by NIST since 1934 for use in calibrating instruments for measuring fineness characteristics of portland cement and other powdered construction materials. SRM 114r is the latest of this series providing certified values for cement fineness by Blaine apparatus, + 45 ?m (No. 325) Sieve, and informational values for particle size distribution by light scattering. ASTM C01.25 Committee on Fineness provided a range of desired materials properties, and the assistance of the Cement and Concrete Reference Lab provided a number of candidate plants with materials conforming to the Committee request. Approximately 1000 kg of cement was procured, homogenized, and packaged. An inter-laboratory study was initiated to develop the data set used to establish certified values. The certified values represent the consensus means and uncertainties for the Blaine and + 45 ?m residue. Informational values on particle size distribution are provided as the mean of the combined wet and dry laser diffraction data.