Mechanical and physical properties for concrete adding metakaolin

• Main Authors: Fan-Sheng Kong, 孔繁盛
• Other Authors: J.J. Chang
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/39164507565537553599

碩士 === 國立臺灣海洋大學 === 河海工程學系 === 92 === Abstract The production of cement consumes much energy and results in pollution due to the emission of CO2. In this study, we seek the alternative in a way to reduce the usage of cement. Metakaolin, which is transformed from kaolin using heat treatment, is used to replace part of cement. The performance for such kind of concrete is evaluated. The replacement percentage for cement using Metakaolin（or silica fume） is 5%, 10% and 15% by cement weight. The compressive strength, splitting tensile strength, water absorption, sorptivity, rapid chloride penetration test, four-probe resistivity were conducted to evaluate the physical and mechanical properties. In addition, scanning electronic microscope (SEM) and EDAX were used to evaluate the change of concrete after carbonation. The results indicate that as the replacement percentage of cement using Metakaolin increased the amount for required mixing water which is due to the densification effect of metakaolin and water absorption effect. Mechanical properties for Metakaolin concrete had better development as the replacement percentage increased. The Metakaolin concrete also had low porosity, low permeability and high resistivity. Overall speaking, 15% replacement of cement by Metakaolin had the best performance in mechanical properties as well as the physical properties. In addition, mix usage of metakaolin and silica fume to replace part of cement shows good compatibility for these two pozzolian materials. Key Words：metakaolin，heat treatment，silica fume，splitting tensile strength，pozzolian material