- Author
- Phan, L. T. | Lew, H. S.
- Title
- Punching Shear Resistance of Lightweight Concrete Offshore Structures for the Arctic: Results of Experimental Study.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Sponsor
- Mineral Management Service, Reston, VA
- Report
- NISTIR 88-4007, November 1988, 176 p.
- Distribution
- Available from National Technical Information Service
- Keywords
- offshore platforms | reinforced concretes | arctic structures | experimental study | lightweight concretes | prestressing | punching shear | prototype | scale models | shear strength
- Abstract
- This report presents the results of the experimental investigation on punching shear behavior of heavily reinforced, thick, lightweight concrete plates and shells. Eighteen concrete plate and shell specimens of 1/6- and 1/4-scale were tested. These were designed to represent typical panels of the perimeter walls of Arctic offshore structures. The specimens were subjected to high-intensity, concentrated load, applied at the center of each specimen. The results of tests indicated that shear reinforcement ratio and curvature (R/t ratio) are the two most influencing factors affecting the punching shear strength and ductility of the specimens. Prestressing with uniform compressive prestress of 500 psi, either in one or two orthogonal directions, was found to have very little effect in terms of improving the punching shear capacity of the speciments. Further, unlike the plates where ultimate punching shear failures were preceded by yielding of shear reinforcement across the crack surfaces, the presence of curvature-induced membrane compression in shells resulted in brittle failure which was caused by crushing of concrete in the compression zone. More importantly, the test results showed that the current ACI Code provisions for punching shear are extremely conservative in predicting the punching shear strength of the specimens of this test program.