An investigation of parameters which affect the strength of lap splices within reinforced masonry is currently being conducted as part of the U.S. Army Corps of Engineers program for Construction Productivity Advancement Research (CPAR). Results from the first phase of the investigation complement existing data regarding lap splices in reinforced masonry and provide a comprehensive review of the effects of masonry unit width, masonry unit type, reinforcing bar diameter, and lap length on both the strength and monotonic behavior of lap splices in masonry.
Results of the experimental investigation have shown that the linear relationship used by current working stress masonry design standards does not accurately describe ultimate splice capacity in some cases. An alternate model, adopted for use in the proposed Masonry Limit States Design Standard, provides a more rational approach to the determination of lap splice lengths in masonry. This method considers reinforcing bar diameter and yield strength, grout tensile strength, and masonry wall thickness when determining splice length. Experimental results are in good agreement with values provided by this analysis and have been used to further verify the applicability of the model.