Research Activities: 1998

Precast I-Girder Cracking Phase II: Causes and Design Details



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Sequential Number


Identification Number


Matching Research Agency

Missouri Department of Transportation (MoDOT)

Principal Investigator

John Myers, Assistant Professor
Civil Engineering
University of Missouri-Rolla
218 Engineering Research Lab.
Rolla, MO 65409
p(573) 341-6618
f(573) 341-6215

Student Involvement

One (1) M.S. student

Project Objective

To perform a statistical analysis on bridge information gathered form Missouri bridges. Monitor typical bridges, one cracked and one uncracked. Provide experimental validation for the cracking causes through finite element analysis. Propose experimental modifications to the current bridge guidelines to eliminate the problem of cracked prestressed I-girders. Determine the severity of the cracking and a method of repair, if necessary.

Project Abstract

Prestressed concrete I-girder bridges constitute approximately 11% of all bridges on Missouri's state highway system. Recently, the Missouri Department of Transportation (MoDOT) has become concerned with the number of these bridges that are experiencing cracking. MoDOT has detected 110 prestressed concrete girder bridges with visible cracks near the girder ends. This project is a collaborative effort of UMR and UMC researchers in close collaboration with MoDOT R&D, Bridge and Bridge Maintenance Divisions, and a MoDOT District.

Task Description

  • A statistical analysis of both cracked and uncracked bridges.
  • Monitoring of one cracked and one uncracked bridge.
  • Development of a FEM model to investigate the serviceability and stress induced performance of a cracked bridge.
  • Determination of a set of proposed modifications to the MoDOT design guidelines.

Anticipated Benefits

Enhanced QC/QA measures for precast/prestressed HPC members and a better understanding of the influence of SA/V on the QC of HPC.

Modal Orientation



Project Start Date:10/01/1998
Project End Date:12/31/2000

Relationship to other Research/Projects


Technology Transfer Activities

To assist MoDOT in the technology transfer of the revised design guidelines and possible repair techniques as the information becomes available. This may include presentations at state offices or dissemination of the report nationally.

Transportation Research Board Keywords

Concrete cracking, finite element analysis, prestressed concrete, thermal expansion, thermal stresses.