1 M.Sc. Student, Department of Civil &Geological Engineering, University of Saskatchewan, Saskatoon, SK, S7N5A9, Canada, alk102@mail.usask.ca
2 Associate Professor, Department of Civil &Geological Engineering, University of Saskatchewan, Saskatoon, SK, S7N 5A9, Canada, lisa.feldman@usask.ca
ABSTRACT
A study completed by Ahmed and Feldman concluded that the tensile capacity of non-contact lap splices, where the lapped bars are in adjacent cells, is 29.3% less than contact lap splices of the same length in masonry assemblages. An experimental program was initiated to evaluate remedial measures that may enhance the tensile capacity of non-contact lap splices such that they can achieve a similar tensile resistance to lap splices where the bars are in contact. Three different remedial techniques were evaluated to explore the effects of adding additional confinement or knockout webs within the splice region. In addition, wall splice specimens featuring standard contact and unaltered non-contact lap splices were constructed as controls. Specimens were tested horizontally under monotonic, four-point loading. The effectiveness of the remedial techniques was determined by visual observations of the resulting distress and an analysis of the measured quantifiable data.
Three courses of knock-out webs within and adjacent to the lap splice length was the highest performing remedial technique in terms increasing the tensile capacity of the lapped bars. The decreased coefficient of variation, which also resulted, can be attributed to the elimination of poor bond at the grout-block interface between the lapped bars and prevented splitting from occurring. However, this remedial technique only managed to achieve 58.9% of the tensile capacity of specimens featuring contact lap splices, leaving further remedial methods to be explored.
KEYWORDS: bond, lap splices (contact & non-contact), concrete block construction,
mitigative construction techniques, web knock-outs, wall splice specimens
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