Observations on Tensile Strength of CSA Cement Mortars Cured at Constant Low Humidity
The purpose of this study was to assess the influence of different types of calcium sulfate on the direct tensile strength, according to ASTM C307, of calcium sulfoaluminate (CSA) cement mortar.Three mix designs were analyzed.Each mix design possessed constant mass amounts of CSA ce ment, calcium sulfate and sand.Two mix designs possessed identical water / cement ratios while one mix design possessed a slightly higher water / cement ratio.Each mix design differed in type of specific calcium sulfate comprising the constant mass amount of calcium sulfate.One mix design solely contained an hydrite (anhydrous CaSO4).The second mix design contained 50 weight % an hydrite and 50 weight % gypsum (CaSO4 · 2H2O).The third mix design sole ly contained gypsum.This study analyzed both CSA cement pastes and CSA ce ment mortars.CSA cement pastes were analyzed through the use of calorime try, thermal gravimetric analysis (TGA/SDT) and powder X-ray diffraction (XRD).From a long-term perspective, all three CSA cement mortar mix de signs experience decreases in direct tensile strength after curing for a specified number of days.TGA/SDT analysis suggests the rate of ettringite decomposi tion is unique for each respective combination of CSA cement and calcium sul fate.
Calcium sulfoaluminate cement Tensile strength Calcium sulfate Ettringite Decomposition
Joshua V Brien Kevin R Henke Kamyar C Mahboub
University of Kentucky,Department of Civil Engineering,Lexington,KY,40506,United States of America University of Kentucky,Center for Applied Energy Research,Lexington,KY,40511,United States of Americ
国际会议
武汉
英文
154-180
2013-10-23（万方平台首次上网日期，不代表论文的发表时间）