Author: Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 170
Book Description
Toward Development of a Non-destructive Technique to Measure the Available Prestress in Prestressed Concrete Girders
Author: Bridge Instrumentation and the Development of Non-destructive and Destructive Techniques Used to Estimate Residual Tendon Stress in Prestressed Girders
Author: Brian M. KukayPublisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages :
Book Description
This research embodied a three-prong approach for directly determining the residual prestress force of prestressed concrete bridge girders. For bridges that have yet to be constructed, outfitting girders with instrumentation is a highly effective means of determining residual prestress force in prestressed concrete bridge girders. This constitutes the first prong. Still, many bridges are constructed without such instrumentation. For these bridges, a destructive technique can be used to directly determine the residual prestress in a prestressed concrete bridge girder. This implies that the girder(s) being tested have already been taken out of service. This constitutes the second prong. For bridges that are anticipated to remain in service that are lacking embedded instrumentation, the development of a non-destructive technique used to estimate the remaining force in the tendons of prestressed bridge girders is extremely important. This constitutes the third prong used to directly determine residual prestress force. The flexural capacity was also determined from field tests and compared to analytical estimates. By design, the code estimates are meant to be conservative. Alternatively, the residual prestress force for in-service members can be determined directly through the non-destructive technique presented in this research. As such, bridge service capacities can be determined directly and do not need to be conservatively estimated.
Evaluation and Repair Procedures for Precast/prestressed Concrete Girders with Longitudinal Cracking in the Web
Author: Maher K. TadrosPublisher: Transportation Research Board
ISBN: 0309118352
Category : Technology & Engineering
Languages : en
Pages : 76
Book Description
This report establishes a user's manual for the acceptance, repair, or rejection of precast/prestressed concrete girders with longitudinal web cracking. The report also proposes revisions to the AASHTO LRFD Bridge Design Specifications and provides recommendations to develop improved crack control reinforcement details for use in new girders. The material in this report will be of immediate interest to bridge engineers.
Extending Span Ranges of Precast Prestressed Concrete Girders
Author: Reid Wilson CastrodalePublisher: Transportation Research Board
ISBN: 0309087872
Category : Concrete bridges
Languages : en
Pages : 603
Book Description
At head of title: National Cooperative Highway Research Program.
Connection of Simple-span Precast Concrete Girders for Continuity
Author: Richard A. Miller (Professional engineer)Publisher: Transportation Research Board
ISBN: 0309087937
Category : Concrete beams
Languages : en
Pages : 202
Book Description
Introduction and Research Approach -- Findings -- Interpretation, Appraisal, and Application -- Interpretation, Appraisal, and Application -- References -- Appendixes.
Investigation of Transfer Length, Development Length, Flexural Strength, and Prestress Losses in Lightweight Prestressed Concrete Girders
Author: Thomas E. CousinsPublisher:
ISBN:
Category : Concrete bridges
Languages : en
Pages : 88
Book Description
Encouraged by the performance of high performance normal weight composite girders, the Virginia Department of Transportation has sought to exploit the use of high performance lightweight composite concrete (HPLWC) girders to achieve economies brought about by the reduction of dead loads in bridges. Transfer length measurements (conducted on two AASHTO Type IV HPLWC prestressed girders) indicated an average transfer length of 17 inches, well below the AASHTO and ACI requirements. Two HPLWC AASHTO Type II girders and a 48 x 8 inch normal weight 4000-psi concrete deck were fabricated. The girders were cast of concretes with a compressive strength of 6380 psi and a unit weight of 114 pcf. Full scale testing of the girders was conducted to evaluate development length and flexural strength in HPLWC composite girders. Embedment lengths of five, six, and eight feet were evaluated. Tests indicated a development length of about 72 inches, marginally below the ACI and AASHTO requirements. All tested girders exceeded their theoretical flexural capacity by 24% to 30%. A third composite Type II girder was cast of high performance normal weight concrete and topped with a 48 x 8 inch normal weight 4000-psi concrete deck. This girder was intended as a control specimen. Prestress losses in the HPLWC AASHTO Type IV girders monitored over a nine-month period were found to be less than those calculated using the ACI and PCI models.
Instrumentation and Monitoring of High Performance Concrete Prestressed Bridge Girders
Author: Vellore S. GopalaratnamPublisher:
ISBN:
Category : Concrete bridges
Languages : en
Pages : 178
Book Description
Time Dependent Deformation in Prestressed Concrete Girder
Author: Y. J. SokalPublisher:
ISBN: 9780867761115
Category : Prestressed concrete beams
Languages : en
Pages : 45
Book Description
Design of Prestressed Concrete Girders Without End Blocks
Author: Rafik Y. ItaniPublisher:
ISBN:
Category : Concrete beams
Languages : en
Pages : 140
Book Description
Method to Evaluate Remaining Prestress in Damaged Prestressed Bridge Girders
Author: Scott Adam CivjanPublisher:
ISBN:
Category : Bridges
Languages : en
Pages : 86
Book Description