Mechanical Properties and Durability of Mortar with Fly Ash and Limestone Powder

• Main Authors: Chong-Li Chen, 陳重利
• Other Authors: Chun-Tao Chen
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/24254399230352900240

碩士 === 國立臺灣科技大學 === 營建工程系 === 102 === This study explores the mechanical properties and the durability of mortar with fly ash and limestone powders. The compressive strength of the mortar was reduced by 10% limestone addition so the fly ash was further added in order to compensate the strength loss by the pozzolanic effects in the long term. The durability of the mortar was also explored, including the sulfate resistance, expansion in water, shrinkage, alkali-silica reaction (ASR), carbonation, and chloride migration. In order to simulate the natural conditions onsite, the carbonation and the chloride migration was conducted in specimens subjected to prestress. In addition, this study tentative used new accelearated ASR techniques, such as pre-carbonation before ASR, carbonation after ASR, and alternative carbonation and ASR, to simulate the combined deteriorations in nature. The accelerated ASR was conducted in accordance to ASTM C1260 and the accelerated carbonation was conducted by exposing the specimens into 50% carbon dioxide. Results showed that the mortar with 15% fly ash and 10% limestone had low shrinkgage, expansion in water, ASR expansion, and no clear strength reduction. Moreover, the carbonation effectively reduced the ASR due to the reduction of alkalis in pore water, densified microstructure, and strength increases.