온도증가에 따른 콘크리트의 색상과 잔존압축강도의 변화

다국어 초록 (Multilingual Abstract)

When reinforced concrete is subjected to high temperatures, compressive strength and elastic modulus of concrete, ductility and yield stress of steel decrease. Degradation of these properties after such an exposure may result in undesirable structural failures and are great importance in terms of the serviceability of buildings. Therefore, changes in material's properties have to be evaluated in decide whether the buildings exposed to high temperature effect will be repaired or demolished.
Assessment of fire damaged concrete usually starts with visual observation of color change, crazing, cracking, and spalling. On heating, a change in color from normal to a pink/red is often observed and this is useful since it coincides with the onset of significant loss of concrete strength.
The purpose of this study is to quantify changes in color for concrete using spectrophotometric method and to identify the relationship between color change and residual compressive strength loss of concrete as temperature increases.
For this purpose, we manufactured concrete samples with varying water-to-cement ratios and heated them to target temperatures of 100, 200, 300, 400, 500, 600, 700 and 800℃ in an electric oven, whereupon their color changes and residual compressive strengths were measured for analysis. The result of the study shows that color change and residual compressive strength in a concrete structure exposed to high temperature have a consistent relationship in quantitative equation, therefore, it may be possible to know how much compressive strength of the concrete reduces by measuring color changes and estimating heating temperature.

목차 (Table of Contents)

• Abstract
• 1. 서론
• 2. 색조분석의 기본 이론
• 3. 실험계획
• 4. 실험결과 및 분석
• 5. 결론
• 참고문헌

참고문헌 (Reference)

1 한국콘크리트학회, "철근콘크리트 구조물의 내화특성" 2005

2 Y. N. Chan, "Residual strength and pore structure of high-strength concrete and normal strength concrete after exposure to high temperatures" 21 (21): 1999

3 Y. Ichikawa, "Prediction of moisture migration and pore pressure build-up in concrete at high temperatures" Nuclear Engineering and design 2004

4 Konica Minolta, "Precise color communication" 2004

5 B. Georgali, "Microstructure of fire-damaged concrete" 27 : 2005

6 ACI 216R, "Guide for Determining the Fire Endurance of Concrete Elements" 2001

7 Ufuk Dilek, P.E., "Evaluation of fire damage to a precast concrete structure nondestructive, laboratory, and load testing" 19 (19): 2005

8 Omer Arioz, "Effect of elevated temperatures on properties of concrete" 42 (42): 2007

9 Nabi Yüzer, "Compressive strength-color change relation in mortars at high temperature" Cement and Concrete Research 2004

10 G. A. Khoury, "Compressive strength of concrete at high temperatures: a reassessment" 44 (44): 1992

11 Joongwon Lee, "Color and Material Property Changes in Concrete Exposed to High Temperatures" 8 (8): 2009

12 BSI, "BSI, Section four. Fire resistance, BS8110 part2"

13 Deng-Fong Lin, "Assessment of fire-damaged mortar using digital image process" 16 (16): 2004

14 N. R. Short, "Assessment of fire damaged concrete using color image analysis" Construction and building materials 2001

15 J. R. dos Santos, "Assessment of concrete structures subjected to fire" 54 (54): 2002