Bulk Oxide Composition - Wet Chemistry
Loss on Ignition - Insoluble Residue
Other than X-ray fluorescence spectroscopy (XRF) for determination of bulk oxide compositions of pressed pellets or fused beads, or, direct measurements of water-soluble ions in liquids in XRF, or, ion chromatography for water-soluble cations and anions in filtrates of deified water-digested samples, or potentiometric titration for acid or water-soluble chloride, the following gravimetric (wet chemical) analyses are routinely done for concrete and masonry:
Determination of soluble silica content in masonry mortar or concrete after digestion in cold hydrochloric acid followed by digestion of the residues in hot sodium hydroxide solution (included in ASTM C 1084 for concrete, or ASTM C 1324 for masonry mortar)
Determination of hydrochloric acid-insoluble residue contents of masonry mortars to determine the proportions of acid-insoluble residues, which, based on optical microscope i.e. if determined to contain acid-insoluble siliceous sands correspond to the sand content of mortar (ASTM C 1324)
Loss on ignition of masonry mortars by successive heating from ambient temperatures to 110, 550, and 950 degrees C for successive loss of free water, combined water from dehydroxylation of hydrous phases, and, carbon dioxide from decomposition of carbonate phases, respectively (ASTM C 1324)
From standard development to analysis of trace elements, CMC uses ICP-AES facilities of a local laboratory.
Total Sulfur by High-T IR Combustion
The rapid CS cube is designed for fast, automated analysis of total sulfur content analysis in aggregates and concrete. Small amounts (0.5 to 1 g) of powdered samples are wrapped in tin foil to avoid dust formation and contamination in the analyzer.
Our rapid CS cube unit comes with an integrated 60-position autosampler for high sample throughput and safe unattended overnight operations. The proprietary blank-free ball-valve technology assures reliable sample feeding without the need for sophisticated and therefore susceptible mechanics. During operation all sample positions are accessible and reloadable at any position and time. The rapid CS cube is free from spectral interferences and works with just one detector and one detection range over the entire concentration range of the analyzer. The IR detector is customized for sulfur and carbon analysis. The result is a very good signal-to-noise ratio, excellent analytical sensitivity, and trouble-free measurements of unknown samples with strongly deviating concentrations. In addition, utilizing one detector for the entire measure range reduces the calibration effort to a minimum.
Analysis is done in accordance with ASTM D 4239 (S in coal and coke), DIN 51724-3 (S in solid fuels) as well as ISO 15178:2000 (S in soil), and EN 15936 (TOC in solids).
The instrument can also be used for determination of total organic carbon (TOC), e.g., in soil, sediment, sludge, and solid waste.