Effects of Partial Replacement of Cement by Fly Ash on The Temperature Rise of Mass Concrete

• Main Author: 林聰邦
• Other Authors: Tsong Yen
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/69266184009257305557

碩士 === 國立中興大學 === 土木工程學系 === 90 === The heat of hydration for cement in mass concrete can not be evolved well resulting in a big amount of heat to be accumulated internally, which will lead to a occurance of thermal crack on the surface of concrete .Using fly ash to replace part of cement in concrete can not only reduced the cement content but also decrease the amount of heat evolution. This study aims to investigate the effects of the thickness of concrete and the replacement of cement with fly ash on the hydration temperature of mass concrete. In this study, three different thickness of concrete specimens(1.5m, 1.0m, and 0.5m) and four fly ash replacement ratio (0%, 10%, 30%, and 50%) are selected. Thermocouples was used for measuring the temperature of concrete. The results shown that with the thicker concrete, the higher hydration temperature at the center of concrete was measured and a bigger difference of temperature between the inner and outer part of the concrete was found. Also, a larger temperature gradient on the cross section of concrete was occurred. In fly ash concrete, with a bigger fly ash ratio, the measured hydration temperature at the center of concrete was lower,and a smaller difference of temperature between the inner and outer part , and a lower temperature gradient of concrete was also found. Consequently, replacing part of cement by fly ash in mass concrete can effectively improve the temperature rise.