Analysis of the effects of vertical pre-release cracks on prestressed concrete bridge girders

2004-11-01
Baran, Eray
French, Catherine
Wyffels, Tina
Vertical cracks, termed "pre-release cracks," beginning at the top flange and propagating downward into the section depth have been observed to develop during the production of long-span prestressed concrete bridge girders. The cracking which is attributed to the restrained shrinkage the concrete and thermal effects during the curing period prior to release of the prestressing strands, tends to be more critical for long-span girders with deep sections and large amounts of prestressing strands. Studies were conducted at the University of Minnesota to investigate the effects of pre-release cracks on the behavior of bridge girders. The effects of the size of pre-release cracks on beam stresses and crack-closure behavior were studied with finite element models. Full-scale Mn/DOT Type-28M prestressed concrete bridge girders incorporating artificially-made pre-release cracks were tested under four-point bending to verify the findings. Closing of the pre-release cracks and the beam strains and deflections were monitored continuously during the load tests. The pre-release cracks were found to cause local changes in the beam strains near the crack locations. Beams with pre-release cracks were observed to undergo flexural crack initiation and crack re-opening at lower loads than similar beams without pre-release cracks.

Suggestions

Analysis of the flexural strength of prestressed concrete flanged sections
Baran, Eray; French, Catherine (Precast/Prestressed Concrete Institute, 2005-01-01)
Inconsistencies in the sectional response of prestressed concrete flanged sections predicted by the AASHTO LRFD and AASHTO Standard Specifications, including the maximum reinforcement limits, may arise due to different interpretations of the equivalent rectangular compressive stress block idealization. Strain compatibility analyses with nonlinear material properties were performed for a variety of non-rectangular prestressed concrete sections to identify the inconsistencies between the two specifications. R...
Experimental Determination of Resistance Characteristics of Support Details Used in Prestressed Concrete Bridge Girders
Baran, Eray; French, Catherine; Schultz, Arturo (American Society of Civil Engineers (ASCE), 2009-09-01)
Static load tests were performed on support details used at the ends of prestressed concrete pedestrian bridge girders to determine the resistance characteristics of girder supports in the direction perpendicular to the longitudinal axis of the girders. The specimens tested represent support details that have also been widely used in prestressed concrete highway bridges in Minnesota and in other states. Two specimens, one representing the free-end detail and one representing the restrained-end detail were s...
Influence of elevated temperature on axially loaded expansive cement grout borehole plug sealing performance
Akgün, Haluk (Thomas Telford Ltd., 2000-10-01)
The strength of expansive cement grout borehole plugs cast in rock cylinders is investigated theoretically and experimentally as a function of curing and testing temperature of the plugged rock cylinder and of borehole size. The distributions of thermally induced stresses and displacements, shear stresses along the plug-rock interface due to an axial stress applied to the plug, and resultant interfacial shear stresses due to a combination of uniform elevated temperature and axial load are studied and analys...
Test method for determining the shear modulus of elastomeric bearings
Topkaya, Cem (American Society of Civil Engineers (ASCE), 2002-06-01)
The shear modulus of the elastomer is the most important material property related to the behavior of elastomeric bearings used principally at supports in bridges. Current methods for determining the shear modulus usually require small test samples cut from manufactured bearings. Such tests are costly, do not necessarily represent the performance of the full-size bearing, and are destructive. A new shear test method, called the inclined compression test, is reported that is nondestructive and only requires ...
Evaluation of the Predictive Models for Stiffness, Strength, and Deformation Capacity of RC Frames with Masonry Infill Walls
Turgay, Tahsin; Durmus, Meril Cigdem; Binici, Barış; Ozcebe, Guney (American Society of Civil Engineers (ASCE), 2014-10-01)
Buildings with masonry infill walls (MIWs) in reinforced concrete (RC) frames are commonly used all around the world. It is well known that infill walls may affect the strength, stiffness, and displacement ductility of the structural system. Different approaches have been adopted in different codes and guidelines to consider the stiffness and strength contribution of MIWs on RC frame behavior. This study compares the ability of the existing guidelines to estimate stiffness, strength, and deformability of RC...
Citation Formats
E. Baran, C. French, and T. Wyffels, “Analysis of the effects of vertical pre-release cracks on prestressed concrete bridge girders,” PCI JOURNAL, pp. 114–131, 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/35630.