This paper examines cracks which occurred at the re-entrant corners at the dapped ends of bulb tee girders used on the MIA Mover APM System at Miami International Airport. Cracks were initially identified during load testing at the precast yard, although typically they did not occur until the beams were erected. The load test and crack mechanism is described herein. Post-erection cracking is compared with that observed under load test conditions and differences are discussed. FDOT criteria were applied in determining the appropriate protection strategy.
- Record URL:
- https://doi.org/10.1061/41193(424)14
- Availability:
- Find a library where document is available. Order URL: http://worldcat.org/isbn/9780784411933
- Supplemental Notes:
- Copyright © 2011 ASCE
- Authors:
- Leverenz, David G.
- Davidson, Thomas E.
- Conference:
- Location: Paris , France
- Date: 2011-5-22 to 2011-5-25
- Publication Date: 2011
I am aware from experience to always add diagonal reinforcing in a re-entrant corner in a slab on grade. I normally require (2)-#5 x 4', with 1' clear from the top of the slab. However, I am now in the position where I have a slab with a textbook 45 degree crack from multiple re-entrant corners within 20 (+/-) days of placement. Re-entrant corners. Re-entrant corners are corners that point into a slab. For example, if one were to pour concrete around a square column, he would create four re-entrant corners. Because the concrete cannot shrink around a corner, the stress will cause the concrete to crack from the point of that corner (See Figure 1).
Language
- English
Media Info
- Media Type: Web
- Monograph Title: Proceedings of the Thirteenth International Conference on Automated People Movers and Transit Systems, 2011
Subject/Index Terms
- TRT Terms: Load tests; People movers; Precast concrete
- Identifier Terms: Miami International Airport
- Uncontrolled Terms: Bulbtee girders
- Geographic Terms: Florida
- Subject Areas: Maintenance and Preservation;
Filing Info
- Accession Number: 01365047
- Record Type: Publication
- ISBN: 9780784411933
- Files: TRIS, ASCE
- Created Date: Nov 29 2011 3:00PM
This paper examines cracks which occurred at the re-entrant corners at the dapped ends of bulb tee girders used on the MIA Mover APM System at Miami International Airport. Cracks were initially identified during load testing at the precast yard, although typically they did not occur until the beams were erected. The load test and crack mechanism is described herein. Post-erection cracking is compared with that observed under load test conditions and differences are discussed. FDOT criteria were applied in determining the appropriate protection strategy.
- Record URL:
- https://doi.org/10.1061/41193(424)14
- Availability:
- Find a library where document is available. Order URL: http://worldcat.org/isbn/9780784411933
- Supplemental Notes:
- Copyright © 2011 ASCE
- Authors:
- Leverenz, David G.
- Davidson, Thomas E.
- Conference:
- Location: Paris , France
- Date: 2011-5-22 to 2011-5-25
- Publication Date: 2011
Language
- English
Reentrant Corner Crack
Media Info
- Media Type: Web
- Monograph Title: Proceedings of the Thirteenth International Conference on Automated People Movers and Transit Systems, 2011
Subject/Index Terms
- TRT Terms: Load tests; People movers; Precast concrete
- Identifier Terms: Miami International Airport
- Uncontrolled Terms: Bulbtee girders
- Geographic Terms: Florida
- Subject Areas: Maintenance and Preservation;
Filing Info
Re Entrant Corner Cracking
- Accession Number: 01365047
- Record Type: Publication
- ISBN: 9780784411933
- Files: TRIS, ASCE
- Created Date: Nov 29 2011 3:00PM