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Abstract
The use of headed reinforcement is relatively new in masonry walls. Research is being conducted to determine if splice lengths can be reduced when heads are present. Previous research tested anchorage of headed bars in concrete and effects of splice length and clear cover in masonry. This project was conducted to further previous research by testing effects of headed reinforcement on splice length in masonry cells.
Tests were performed with a total of 12 specimens. The specimens were constructed using ASTM C 90 dimensions of standard CMU block. There was a combination of 8-inch block cells and 12-inch block cells. Variables of splice length, development length, compressive strength and material confinement or clear cover were tested. Limit states of single blowout, compression strut or a combination of the two were developed and analyzed to determine the capacity of the specimens.
Due to the limited number of test specimens, definite conclusions to the effect of headed reinforcement on lap splices in masonry cells could not be determined. Development length had no direct effect on the capacities, more cover led to higher capacity and longer splice length led to increased capacity. An equation was developed using previous research for in-plane and out-of-plane blowout failures. It was determined that the in-plane equation was the best fit for longer splice lengths. More research is needed to determine the effects of splice length on capacity for short splice lengths.