2004 Fiscal Year Final Research Report Summary

New crack width control design method for continuous composite girder bridges accounting for initial crack state

Research Project

Project/Area Number	15560402
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Structural engineering/Earthquake engineering/Maintenance management engineering
Research Institution	Nagaoka University of Technology
Principal Investigator	NAGAI Masatsugu Nagaoka Univ.of Technology, Civil and Environmental Engineering, Professor, 工学部, 教授 (20207971)
Co-Investigator(Kenkyū-buntansha)	IWASAKI Eiji Nagaoka Univ.of Technology, Civil and Environmental Engineering, Associate Professor, 工学部, 助教授 (10223380)
Project Period (FY)	2003 – 2004
Keywords	continuous composite girder / concrete / crack / initial crack st / stabilized crack state / control design / reinforcing bars / durability
Research Abstract	In this research, we proposed a new crack width control design method in continuous composite girder bridges. Cracking state is divided into the following three states, namely ; crack occurrence (the sum of concrete stress due to shrinkage and vehicle loading reaches tensile strength of the concrete), initial cracking (cracks appear successively), stabilized crack state (no crack initiation is observed and crack width starts increasing). Depending on the crack states, the formulae evaluating the crack width are presented. In addition, the stress in reinforcing bars is also proposed. The validity of the proposed new design method is confirmed through experimental research.

(3 results)