Evaluation of Hydration Heat Properties of Mass Concrete and Crack Resistance Performance in Practical Large Underground Structures Using Ternary Blended Cement

3성분계 시멘트를 활용한 실 대형 지하구조물의 매스 콘크리트 수화 발열 특성 및 균열 저항성 평가

Abstract

In this study, in order to evaluate Hydration Heat Characteristics of mass concrete using ternary blended cement for large underground structures, the analysis considering the temperature history and the thermal characteristics inside the actual structure was performed. The results of the analysis are compared with the measured values to verify the reliability of the analysis and to evaluate the crack resistance performance. As a result of the measured the actual structure temperature, The adiabatic temperature rise coefficients K and ${\alpha}$ of the slab were $35.1^{\circ}C$ and 0.72, respectively, and the wall was analyzed as $29.3^{\circ}C$ and 0.67. The analytical results and the correlation coefficients(r) were 0.95 and 0.98, respectively. As a result of evaluating the crack resistance of slab and wall, the minimum crack index of slab and wall was 1.22 and 1.20, respectively. These results were found to satisfy the site management standards.

본 연구에서는 실 대형 지하구조물의 매스 콘크리트의 수화 발열 특성 및 균열 저항성을 평가하기 위하여 실 구조물 내부의 온도이력 및 열 특성을 고려한 해석을 실시하였다. 해석 결과는 실측값과 비교를 통하여 해석의 신뢰성을 검증하였으며, 균열에 대한 저항성을 평가하였다. 실 구조물의 온도 측정 결과, 슬래브의 단열 온도 상승 계수 K 및 ${\alpha}$은 $35.1^{\circ}C$와 0.72이었으며, 벽체는 $29.3^{\circ}C$와 0.67로 분석되었다. 분석된 단열온도상승계수 및 현장조건을 적용한 수화열 해석 결과 실측값과 상관계수(r)는 각각 0.95 및 0.98로 나타났다. 슬래브 및 벽체의 균열 저항성을 평가한 결과 슬래브 및 벽체의 최소 균열지수는 각각 1.22 및 1.20으로 나타나 현장 관리기준을 만족하는 것으로 나타났다.

Fig. 1. Slab location and field foreground

Fig. 2. Slab drawing and casting section

Fig. 3. Wall location and field foreground

Fig. 4. Wall drawing and casting section

Fig. 5. Micro-hydration and cumulative micro-hydration heat of mixed binder

Fig. 6. Losition of slab and temperature measurement area

Fig. 7. Losition of wall and temperature measurement area

Fig. 8. Temperature gauge installation foreground

Fig. 9. Slab modeling

Fig. 10. wall modeling

Fig. 11. Temperature history of slab

Fig. 12. Temperature history of wall

Fig. 13. Temperature distribution of construction phase of slab

Fig. 14. Analysis result and actual measurement result

Fig. 15. Analysis point of the slab

Fig. 16. Result of hydration heat analysis of slab

Fig. 17. Crack stability of slab

Fig. 18. Temperature distribution of construction phase of wall

Fig. 19. Analysis result and actual measurement result

Fig. 20. Analysis point of the wall

Fig. 21. Result of hydration heat analysis of wall

Fig. 22. Crack stability of wall

Table 1. mass concrete mix according to applied member

Table 2. Chemical composition of mixed binder

Table 3. Cumulative micro-hydration heat of mixed binder

Table 4. Physical properties of aggregate

Table 5. Physical properties of chemical admixtures

Table 6. Hydration heat analysis condition

Table 7. Thermal and mechanical properties

Table 8. Evaluation result of basic quality

Table 9. Measurement result of hydration heat

Table 10. Results of temperature history analysis of slab

Table 11. Crack index of slab

Table 12. Results of temperature history analysis of wall

Table 13. Crack index of wall