New Test Method for Durability of Concrete

• Main Authors: JIANG,NAI REN, 姜乃仁
• Other Authors: Chen H. J.
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/95895487600650130302

碩士 === 國立中興大學 === 土木工程學系 === 93 === Abstract Current test methods for assessing the durability of concrete primar-ily are based on the ability which the substances (the gas, liquid or ion) from the surface of concrete “permeate” into the internal part. In this re-search, a reverse thinking is provided that the durability of concrete may be estimated by the Oven Drying Test method which the moisture is “re-leased” from concrete. Moreover, the comparison with the frequently used test methods (Electrical Resistance Test, Permeability Test and Mercury Intrusion Porosimetry Test－MIP) for concrete’s durability is made in order to investigate the feasibility of the presented approach. Test results show that the rate of weight loss for concrete in Oven Drying Test increases with water-cement ratio (w/c) increasing, and this is ascribed to the higher amounts of capillary pores forming form the more free water without participating the hydration of cement for the paste with high w/c. Besides, the lower density of internal pore stricture is, the more easily the moisture released. It will result in the higher total rate of weight loss and be harmful to the durability of concrete. On the other hand, the values of the accumulative rate of weight loss obtained form Oven Drying Test and the data of durability tests both exhibit the superior correlation. In which, for the test results on the temperature of 100°C, the values of the correction coefficient (R2) by linear regression can be up to above 0.91. This indicates that regarding the Oven Drying Test as one of the tests for evaluating the durability of concrete is considerably practica-ble.