- Author
-
Woodward, K.
|
Rankin, F.
- Title
- Influence of Aspect Ratio on Shear Resistance of Concrete Block Masonry Walls.
- Coporate
- National Bureau of Standards, Gaithersburg, MD
- Report
-
NBSIR 84-2993,
January 1985,
65 p.
- Distribution
- Available from National Technical Information Service
- Keywords
-
concrete blocks
|
aspect ration
|
compression
|
masonry
|
shear
|
strength
|
structural testing
|
walls
|
shear stress
|
shear strength
- Abstract
- The results from tests on seven ungrouted and unreinforced concrete block masonry walls are presented. The emphasis of the reported research is on the influence of aspect ratio (wall height-to-length) on the relationship between lateral in-plan load resistance and vertical in-plane compressive stress. The walls are fabricated from similar materials by the same experienced mason. The masonry units are hollow concrete block having a nominal compressive strength of 1800 psi based on the gross area. The mortar is proportioned as a Type S. The walls have nominal heights and thicknesses of 64 in. and 8 in., respectively. Three different wall lengths are used: 48 in., 80 in., and 96 in. The walls are tested in the NBS Tri-directional Testing Facility using fixed ended boundary conditions at the top and bottom of the wall. Lateral in-plane displacements were applied at the top of the wall while maintaining a constant compressive axial (vertical) stress. The vertical compressive stress is varied for each of the different wall lengths. The test results indicate a relatively weak effect of aspect ratio on the shear stress at diagonal cracking for aspect ratios less than or equal to one and a nearly linear relationship between maximum shear stresses and veritcal compressive stresses.