Analysis of the ASTM round-robin test on particle size distribution of Portland cement:

Abstract

A distribution of sizes or particle size distribution (PSD) is an essential property of cement powder. The only standard method to measure the PSD of cement, namely ASTM C115 [ 11 is limited in scope; this standard only describes a method for determining "fineness" with a lower size detection limit of 7.5 pm. As there is no standard procedure covering the whole range of cement PSD, the implementation of different measurement methods varies widely within the industry. A first report [2] was prepared to examine the methods used in the cement industry. The high variability of the data led to the necessity for further research.ASTM committee C01.25.01 sponsored a second round-robin test to measure the PSD of cement. The aim of the current report is to analyze the data generated during that test and to summarize the various approaches available to measure the PSD of cement. The analysis of the data is conducted in two parts. In the first part, an attempt is made to establish a reference distribution using a standard cement powder (SRM 114p), improving the results already obtained from the first round-robin. This is followed by examination of the parameters and methodology used by the participants in order to initiate discussion on developing a standard test method for cement PSD to be submitted for ASTM consideration. The report provides all raw data collected during the round-robin tests, and the results of a statistical analysis of the collected data. AcknowledgementsThe authors would like to thank the ASTM Task Group CO1.25.01 for providing the opportunity for this round-robin. We would like to thank all participants of the round-robin (listed below by alphabetical order of the institution) for providing time and staff to perform the tests.Also, we would like to thank Robin Haupt and the staff of the Cement and Concrete Reference Laboratory (CCRL), who were instrumental in providing the samples to the round-robin participants.

Measurement of Particle Size Distribution in Portland Cement Powder: Analysis of ASTM Round Robin Studies

“…The bootstrap method replaces difficult (or even impossible analytical) solutions to statistical problems with raw computing power (details on the bootstrap method are provided in Appendix C of ref. [Ferraris et al, 2002a]). The bootstrap method does not explicitly provide the criteria needed to determine outliers.…”

“…r Specified method (SM): all participants were requested to use a set of parameters specified by NIST (Appendix D of ref. [Ferraris et al 2002b]).…”

“…Four portland cements provided by the Cement and Concrete Reference Laboratory (CCRL) were included in the test: 131, 132, 135, and 136 (numbers were assigned by CCRL). The compositions and characteristics of these cements, measured as part of the CCRL proficiency program, are provided elsewhere (Ferraris et al, 2002a). The cement powder standard reference material (SRM) 114p was also included in this test.…”

“…Two portland cements provided by CCRL were included in the tests: 143 and 144. The characteristics of these cements, as measured in the CCRL proficiency program, are given elsewhere [Ferraris et al, 2002b]. SRM 114p was again included, with the specific intent of establishing a consensus reference PSD.…”

“…This is followed by an examination of the parameters and methodology used by the participants in order to initiate discussion on developing a standard test method for cement PSD to be submitted for ASTM consideration. The complete set of raw data collected during the round robin tests, and the accompanying statistical analyses, are available in two separate reports (Ferraris et al, 2002a(Ferraris et al, , 2002b.…”