Title:
Relation of Shrinkage to Moisture Content in
Concrete Block
Author(s):
George L. Kalousek, Richard J. O’Heir, Kenneth L. Ziems, and Edwin L. Saxer
Publication:
Journal Proceedings
Volume:
50
Issue:
11
Appears on pages(s):
225-240
Keywords:
no keywords
DOI:
10.14359/11758
Date:
11/1/1953
Abstract:
Six types of aggregates and five curing methods used in commercial block production were used for shrinkage studies and strength determinations of concrete masonry units. Shrinkage and moisture loss were determined at 73 = 3 F in a cycle consisting of exposure to air at 25 percent relative humidity, immersion in water, exposure to air at 70 percent relative humidity, followed by exposure to air at 25 percent relative humidity. Autoclaved products underwent about half the shrinkage shown by units cured by other methods. Curing 6th steam at atmospheric pressure up to 170 F or moist air at 73 F tended to give the same results for each aggregate. Sand and gravel units shrank the least; cinders, expanded shale, expanded slag, and sintered shale gave similar results which were somewhat higher than that for sand and gravel. Pumice units showed slightly higher shrinkage than the latter group. The data show that a 40 percent moisture loss does not generally represent more than about 20 to 50 percent of potential shrinkage occurring at 25 percent relative humidity.