Tensile strength of concrete or masonry is a fundamental material characteristic used to predict crack formation. ASTM C 496 and C 1006 are specifically designed to determine the splitting tensile strength of concrete cylinders and masonry units, respectively. Finite element studies for the above tests were completed with the maximum tensile strength compared to the theoretical value in the corresponding ASTM equations. The objectives of this paper are as follows: (1) evaluate current ASTM test methods to determine splitting tensile strength using finite element analysis; (2) evaluate the splitting tensile strength of masonry assemblages through modifying an existing ASTM test; (3) evaluate the application of ASTM test methods to determine the splitting tensile strength of autoclaved aerated concrete; and (4) evaluate a proposed ASTM test to evaluate the splitting tensile strength of thin-bed mortar used in AAC construction. A case study of the splitting tensile strength of autoclaved aerated concrete is used to propose a single test method for this new material.