Recommended Citation
Varma, A. H, Olek, J., Williams, C. S., Tseng, T.-C., Wang, S., Huang, D., & Bradt, T. (2021). Post-fire assessment of prestressed concrete bridges in Indiana (Joint Transportation Research Program Publication No. FHWA/IN/JTRP-2021/05). West Lafayette, IN: Purdue University. https://doi.org/10.5703/1288284317290
DOI
10.5703/1288284317290
Abstract
This project focused on evaluating the effects of fire-induced damage on concrete bridge elements, including prestressed concrete bridge girders. A series of controlled heating experiments, pool fire tests, material tests, and structural loading tests were conducted. Experimental results indicate that the portion of concrete subjected to temperatures higher than 400°C loses significant amounts of calcium hydroxide (CH). Decomposition of CH increases porosity and causes significant cracking. The portion of concrete exposed to temperatures higher than 400°C should be repaired or replaced. When subjected to ISO-834 standard fire heating, approximately 0.25 in. and 0.75 in. of concrete from the exposed surface are damaged after 40 minutes and 80 minutes of heating, respectively. Prestressed concrete girders exposed to about 50 minutes of hydrocarbon fire undergo superficial concrete material damage with loss of CH and extensive cracking and spalling extending to the depth of 0.75–1.0 in. from the exposed surface. These girders do not undergo significant reduction in flexural strength or shear strength. The reduction in the initial stiffness may be notable due to concrete cracking and spalling. Bridge inspectors can use these findings to infer the extent of material and structural damage to prestressed concrete bridge girders in the event of a fire and develop a post-fire assessment plan.
Report Number
FHWA/IN/JTRP-2021/05
Keywords
prestressed concrete, bridge girder, fire, post-fire, damage, assessment
SPR Number
4221
Performing Organization
Joint Transportation Research Program
Sponsoring Organization
Indiana Department of Transportation
Publisher Place
West Lafayette, IN
Date of this Version
2021