Title:
Effects of Reinforced Concrete Properties on Resistance to Hard Projectile Impact
Author(s):
Avraham N. Dancygier and David Z. Yankelevsky
Publication:
Structural Journal
Volume:
96
Issue:
2
Appears on pages(s):
259-267
Keywords:
aggregates; concretes; high-performance concrete; impact strength; polymer concrete
DOI:
10.14359/617
Date:
3/1/1999
Abstract:
Resistance of reinforced concrete structural elements to hard projectile impact is a complex problem that has been extensively studied by mainly empirical means. Common design of reinforced concrete elements to resist hard projectile impact is carried out by calculating their proper thickness utilizing existing formulas.The reinforced concrete element resistance to the impact is expressed by its concrete compressive strength. The current design formulas do not allow the design of high- strength concrete barriers, as they are limited to normal strength concrete, nor do they include other parameters that may affect the barrier’s resistance. These other parameters include the aggregate type and size and the reinforcement ratio, as well as the reinforcing bar diameter and spacing, etc. Some of these parameters and their effect on the barrier's performance were examined in a laboratory experimental study. The specimens in this study were made of normal and high-strength concrete (NSC and HSC, respectively), polymer concrete (PC), and concrete with a front face layer of basalt aggregates. The reinforcement consisted of steel mesh near the plate’s rear faces and included smooth and deformed steel reinforcing bars, small diameter (0.5-mm) steel wires, and woven and nonwoven steel meshes. A limited number of specimens included hooked steel fibers. Different reinforcement ratios and reinforcement spacings have been examined. At the end of each test, measurements of the rear face damage (crater size and volume) were documented, and the specimen’s perforation resistance (and its dependence on projectile velocity) was evaluated. These results indicate the advantage of HSC and PC in enhancing perforation resistance, and the effect of the different concrete and reinforcement properties on the rear face damage level of the perforated barriers.