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Description This publication contains information of interest to persons specifying and designing masonry construction. It provides current research on masonry units, mortar and grout and their components, and masonry assemblages. The majority of the papers contained in this book deal with the performance of the assemblage of masonry units and mortar.

The failure of masonry in laboratory testing of walls and prisms and certain aspects of grouted construction is often the result of tensile splitting. These tensile stresses arise from differences in modulus of elasticity and Poisson's ratio between the masonry unit and mortar or grout. Since tensile splitting is so prevalent in masonry construction, a better means of evaluating the tensile strength of masonry units is needed. A splitting tensile test is proposed as a means of measuring tensile strength of masonry units. Splitting strength is compared to standard strength tests for 14 clay units and 14 concrete block units. Uniform failure modes and strengths support the adoption of a splitting test as a standard of masonry unit strength.

It is customary to relate the compressive strength of the masonry to that of its components: mortar and units. The correlation between solid unit compressive strength, mortar type and assemblage compressive strength is well documented, and is generally independent of unit coring. The relationships of prism components and prism dimensions to assembly compressive strength and modulus of elasticity for hollow brick are presented in this paper. Hollow brick meeting the requirements of ASTM C 652 in four widths were selected. Portland cement-lime mortars, Type N, S, M by proportions, were used. Both face-shell and full mortar bedding were used to construct prisms with height to thickness ratios from 2 to 5. Mortar, brick and prisms were tested in compression. Deformations measured during prism testing permitted the determination of modulus of elasticity in compression. Hollow unit masonry prisms fail by tensile splitting of the crosswebs, regardless of their aspect ratio. Prism compressive strength and modulus of elasticity are influenced least by fully bedded, stack bond prims. Compressive strengths of prisms made from hollow brick have similar relations to h/t and mortar strength as prisms of solid brick, but less dependence on unit strength.

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