Title: Behavior of Reinforced Concrete Walls with Interior Plaster Coating under Exterior Hard Projectile Impact
Author(s): Avraham N. Dancygier, David A. Yankelevsky, and Hadassa Baum
Publication: Materials Journal
Appears on pages(s): 116-125
Keywords: adhesion; impact; plaster; reinforced concrete
This paper presents an experimental study on the impact response of protective reinforced concrete structural elements that are coated with plaster on their interior faces. Even when a structural element’s perforation is prevented, impact conditions may initiate rear face scabbing due to high-intensity reflected tensile stress waves at the element’s rear face. Israeli standards for civil defense shelter design forbid any interior wall coating, such as plaster or wall tiles, as they may be easily detached upon impact and produce scabbing fragments. Following the Gulf War, a new Israeli civil defense policy became effective, where the protective spaces have been included within the dwelling units. Although plaster coating is the common finish work of the entire interior of a dwelling unit, it seems to a priori contradict the above requirements of scabbing prevention. Further study of the problem and investigation under impact conditions are therefore required to better understand the behavior of the concrete-plaster composite under local hard projectile impact. An experimental program was conducted at the laboratory and included response studies of reinforced concrete specimens to hard projectile impact. The specimens with plastered rear faces were impacted at the center of their front faces. The results showed different responses of various types of plaster coating and demonstrated the importance of parameters that affect the specimens’ performance under impact loads, which are mainly the plaster-background adhesion strength, the plaster density and stiffness, and the improved toughness of the plaster layer. The latter is obtained by reinforcing the plaster with a fiberglass mesh.