Assessment of Temperature Evolution and Early-Age Thermal Cracking Risk in Segmental High-Strength Concrete Box Girder Diaphragms

Autor: Tam Duc Tran, Tuyet Thi Hoang, Mang Tia, Thuan Huu Nguyen, Tu Anh Do
Rok vydání: 2021
Předmět:
Zdroj: KSCE Journal of Civil Engineering. 26:166-182
ISSN: 1976-3808
1226-7988
DOI: 10.1007/s12205-021-2148-5
Popis: Three-dimensional finite element (FE) thermal and stress models were created to compute the temperature evolution, thermal stress and potential of cracking in a segmental concrete box girder segment during construction. User-defined subroutines were developed in the ANSYS program to activate the degree of hydration-dependent heat rate and material properties, and creep behavior in the thermal and stress calculations. The developed FE model was verified with experimental measurements of a concrete cube. Adiabatic temperature rise, together with compressive strength and splitting tensile strength for a high-strength concrete mix typically used in construction of box girders were tested and incorporated in the subroutines. The effect of casting time and placement season (summer and winter), initial concrete temperature change, and insulation on the risk of cracking in a cast-in-situ box girder segment at early ages was investigated using the proposed model. The results indicate that the temperature difference between the segment’s middle and the gate corner is very large leading to a high cracking risk. Use of an insulation material such as blankets along with casting concrete at the nighttime would significantly lessen the thermal tensile stress and thus could reduce cracking risk in the segment.
Databáze: OpenAIRE
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