Title:
Pyrolysis-Gas Chromatography/Mass Spectrometric Methods for the Determination of Chemical Additives in Portland Cement and Concrete
Author(s):
A. Jeknavorian and E. F. Barry
Publication:
Symposium Paper
Volume:
288
Issue:
Appears on pages(s):
1-19
Keywords:
admixture content in concrete; chemical admixture; mass spec¬trometry; pyrolysis-gas chromatography; thermal desorption.
DOI:
10.14359/51684227
Date:
9/14/2012
Abstract:
Novel methods based on thermal desorption (TD) and pyrolysis gas chromatog¬raphy (pyr-GC-MS) have been developed for the determination of chemical additives that are either inter-ground with cement clinker during the manufacture of portland cement or admixed during the production of portland cement concrete. This technique has been found to be readily applicable for phenol, glycol, and alkanolamine-based cement grinding aids as well as a number of different chemical admixtures such as naphthalene sulfonate form¬aldehyde condensate (NSFC), and two durability enhancing admixtures, a calcium nitrite-based corrosion inhibitor and a shrinkage reducing agent (SRA) comprised of isomeric glycols and ethers (SRA). Overall, the pyrolysis gas chromatographic-mass spectrometric (pyr-GC/MS) analysis of cement and concrete has the potential to be far more specific and less tedious than the common extraction-spectroscopic based methods currently used. Front end in-situ derivatization can further expand the capability of pyr-GC/MS by volatil¬izing otherwise thermally unstable or strongly adsorbed additives in cement and concrete.