Field test on temperature field and thermal stress for prestressed concrete box-girder bridge
Baoguo CHEN , Rui DING , Junjie ZHENG , Shibiao ZHANG
Front. Struct. Civ. Eng. ›› 2009, Vol. 3 ›› Issue (2) : 158 -164.
Field test on temperature field and thermal stress for prestressed concrete box-girder bridge
A field test was conducted to investigate the distribution of temperature field and the variation of thermal stress for a prestressed concrete (PC) box-girder bridge. The change of hydration heat temperature consists of four periods: temperature rising period, constant temperature period, rapid temperature fall period and slow temperature fall period. The peak value of hydration heat temperature increases with the increasing casting temperature of concrete; the relation between them is approximately linear. According to field tests, the thermal stress incurred by hydration heat may induce temperature cracks on the PC box-girder. Furthermore, the nonlinear distribution of temperature gradient and the fluctuation of thermal stress induced by exposure to sunlight were also obtained based on continuous in-situ monitoring. Such results show that the prevailing Chinese Code (2004) is insufficient since it does not take into account the temperature gradient of the bottom slab. Finally, some preventive measures against temperature cracks were proposed based on related studies. The conclusions can provide valuable reference for the design and construction of PC box-girder bridges.
box-girder bridge / field test / hydration heat / temperature field / temperature gradient / thermal stress
| [1] |
|
| [2] |
|
| [3] |
|
| [4] |
|
| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
|
| [11] |
|
| [12] |
|
| [13] |
China Highway Planning and Design Institute. General Code for Design of Highway Bridges and Culverts (JTG D60-2004). Beijing: China Communications Press, 2004 (in Chinese) |
| [14] |
British Standard Institute. BS5400, Part 5, Concrete and composite bridges. London, 1979 |
| [15] |
|
Higher Education Press and Springer-Verlag Berlin Heidelberg
/
| 〈 |
|
〉 |