Calcium oxychloride has been reported to form in cementitious materials when calcium chloride (CaCl2) solutions react with calcium hydroxide [Ca(OH)2]. In this study, Ca(OH)2 is mixed with CaCl2 solutions with concentrations of 5 %, 10 %, 15 %, 20 %, 25 %, and 30 % by weight, using a 1:1 M ratio of Ca(OH)2 to CaCl2. The Ca(OH)2-CaCl2 solution mixtures are subject to a cooling and heating cycle. Volume change is measured to quantify the phase transformation associated with calcium oxychloride. Low-temperature differential scanning calorimetry (LT-DSC) is used to construct a phase isopleth, which is used to quantify the phase transformation associated with calcium oxychloride. Hysteresis is observed in the volume-change measurement during the cooling–heating cycle. In a temperature range of 50°C to 0°C, the formation of calcium oxychloride is complete for the 20 %, 25 %, and 30 % CaCl2 solutions. The liquidus temperatures at which calcium oxychloride is expected to form from LT-DSC during heating match those from the volume-change measurements.

2017
ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959
All rights reserved. This material may not be reproduced or copied, in whole or part, in any printed, mechanical, electronic, film, or other distribution and storage media, without the written consent of the publisher.
You do not currently have access to this content.