Compression Characteristics of Concrete Block Masonry Prisms

This paper reports the results of part of a test series to establish stress-strain relationships for hollow, solid, and grout filled concrete block masonry. Included as part of the discussion of the interpretation of previous test programs is a comparison of the influence of the use of prisms with heights of two, three, four, and five blocks. Using the four-block-high prism as the standard, the average moduli of elasticity and the shape of the stress-strain relationship to failure are determined for the hollow, solid, and grouted cases for compression normal to the bed joint and parallel to the bed joint. Strengths for compression normal to the head joint are approximately 25% lower than for compression normal to the bed joint. In addition, strengths for grouted and solid prisms are approximately 35% lower than for hollow blocks. The moduli of elasticity also vary in nearly the same proportions.