Improved Method for Testing Grout used as Masonry Cell Fill

Currently, ASTM C 1019 “Standard Method of Sampling and Testing Grout” governs the compression testing of grout used in masonry construction. This test method utilizes masonry units from the project as the mold to cast the grout specimens for compressive strength testing, thereby accounting for the absorption of the masonry units and its corresponding affect on compressive strength of the test specimens. However, due to the cost, time, materials, space and laboratory ability required for this test, many times the owner or contractor opts for standard concrete cylindrical specimens cast in nonabsorbent molds.

This research investigates the use of a low cost, efficient, single unit mold which produces compressive strength results within an acceptable range of that produced by the ASTM C 1019 specimens. With the current method, many physical defects are inherent with the specimens, such as a concave end, non-square cross-section, ends not perpendicular to axis, and sloped ends. The proposed method will eliminate these types of problems and yield more consistent results with much greater ease and lower cost.