高鋁混凝土在高溫下之力學性質研究

A Study on Mechanical Properties of High Alumina Concrete under High Temperature

何佳忠(JIA-JHONG HO)

指導教授 ： 干裕成

朝陽科技大學/理工學院/營建工程系/碩士(2019年)

摘要

高鋁混凝土可作為耐高溫及核設施防輻射用途之屏蔽材料，因此配比會添加些能防輻射的材料，如氧化鋁砂來提高屏蔽效果。但高鋁混凝土在水化過程中，會因為溫度上升改變水化產物結晶結構，導致強度下降。此現象不只是影響結構強度，尚須考量輻射外洩之潛伏危機，因此必須尋求高鋁混凝土強度可能降低的問題。另外，台灣位於板塊之間地震頻繁，地震主要會造成房屋倒塌、損壞之外，偶而會伴隨著火災，因此必須對高鋁混凝土承受高溫後之力學性質及破裂韌性，進行評估及參考。
　　本研究主要研究含氧化鋁砂、矽灰及強塑劑之高鋁混凝土，經過高溫後的行為，進行系統性之探討，並與常重混凝土來比較各種力學性質；並藉由混凝土破壞力學實驗，評估比較破裂韌性。試驗結果顯示，常溫下氧化鋁砂高鋁混凝土抗壓強度及彈性模數明顯高於高鋁混凝土；但在800℃之時，則呈現相反情形。此外，高鋁混凝土在溫度23℃至400℃之間時，破裂行為呈現比常重混凝土有較大之破裂能。氧化鋁砂高鋁混凝土及添加矽灰高鋁系混凝土在添加強塑劑後，承受溫度至800℃時，破裂韌性則完全喪失。
關鍵字：高鋁混凝土、矽灰、氧化鋁砂、高溫、強度、破裂韌性

關鍵字

高鋁混凝土 ； 矽灰 ； 氧化鋁砂 ； 高溫 ； 強度 ； 破裂韌性

並列摘要

High-aluminum concrete can be a shielding material for nuclear facilities for the concern of radiation protection ability rather than strength. However, in the process of hydration, high-aluminum concrete will lead to conversion effect and decrease the strength due to the elevation of temperature. This affects not only the structural strength, but also results in radiation leakage. Nevertheless, the buildings in Taiwan often suffer the damage due to earthquake and fire. Thus, it is necessary to figure out the mechanical properties and fracture toughness of high-aluminum concrete after damage in high temperature.
This research investigates the mechanical properties of high alumina concrete with the inclusion of alumina oxide, silica fume and superplasticizer in high temperature. Five mixture designs of concrete and three temperatures (23 °C, 400 °C and 800 °C) were selected in this study. Mechanical properties and fracture toughness were evaluated in the experimental program. The test results showed that the strength of concrete decreases with the increase of temperature for all concretes. A-HAC behaves higher strength and more ductile than normal concrete at temperature between 23°C and 400 °C. The high-aluminum concrete including silica fume performs higher compressive strength and elastic modulus than high-aluminum concrete. However, the inclusion of superplasticizer in SF-A-HAC turns out lower strength at high temperature. Its fracture toughness is completely loss at 800 °C.
Key words: high alumina concrete, silica fume, alumina oxide, high temperature, strength, fracture toughness

並列關鍵字

high alumina concrete ； silica fume ； alumina oxide ； high temperature ； strength ； fracture toughness

參考文獻

參考文獻

1.臺灣電力公司核能工通中心，「輻射與環境」，行政院原子能委員會核能研究所，臺北，第1-12頁，1997。

2.Kinnol M., et al., “Low-Activation Multilayer Shielding Structure of LightWater Reactor Using Various Types of Low-Activation Concrete,” Progress in Nuclear Science and Technology, Vol. 1, pp.28-31, 2011.

3.S.N.Ghosh, “CEMENT AND CONCRETE SCIENCE & TECHNOLOGY, ” India, pp. 263-267, 1991.

4.Bradbury C., etc., “The conversion of high alumina cement/concrete, ” Materials Science and Engineering, Volume 23, Issue 1, pp. 43-53,1976.