• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.1081-1084
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• 2008

Column specimens were constructed with main parameters significantly affecting the strength of the compression lap splice, such as lap length, spacing of lapped bars, amount and location of transverse reinforcements, and concrete strength. An experimental study has been conducted with column specimens in concrete strength of 40 to 60 MPa. Diameters of lapped reinforcing bars are 22 mm. An axial load was monotonically applied to the column specimens. All specimens failed in a brittle sudden manner and cover concrete was blasted out at maximum load. Compression lap splice strengths of specimens were evaluated from strains measured at the beginning of the lap length. Effects of the main parameters on the strengths of compression lap splice are assessed. Similarly to strengths of tension lap slice, the compression splice strength is found to be affected by lap length, spacing of lapped bars, transverse reinforcements.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.136-143
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• 2015

Galvanizing is one of the method used to solve the problem of corrosion of reinforcement in concrete structures. There few research reported in the literature regarding the effect of galvanized coating on the behavior of lap splices in concrete beams. The objective of this study was to determine whether galvanized rebar adversely affects lap splice behavior and bond strength. Concrete beams reinforced with black or galvanized rebar were tested in flexure. The test variables included the presence of galvanized rebar steel diameter, and lengths of lap splices. The study concentrated on comparing crack, failure pattern, and bond strength. The ultimate behavior of beams reinforced with galvanized rebar was not significantly different from that of black steel reinforced beams. Therefore, the test results indicated that the use of galvanizing-coated rebar had no adverse effect on behavior in lap splices of rebar compared to the use of black rebar.

• Journal of the Korea Concrete Institute
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• v.22 no.5
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• pp.659-666
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• 2010

Although the compression splice needs not be longer than the tension slice due to existence of end bearing, current design codes impose a longer compression lap splice than a tension lap splice in high strength concrete. Hence, new criteria for the compression lap splice including the effects of concrete strength need to be sought for economical design involving ultra-high strength concrete. An experimental study has been conducted with column specimens in concrete strength of 80 and 100 MPa. Test results show that the splice strength can be evaluated to be proportional to square root of compressive strength of concrete. Bar stress developed by end bearing is not affected by splice length and is expressed with a function of the square root of concrete strength. Mean value of stresses developed by end bearing is 16.5 square root of $f_{ck}$. The stresses developed by bond in compression splices are nearly identical to those in tension splices and, therefore, strength increment of compression splices is attributed to end bearing only. From regression analysis of 58 tests, a design equation is proposed for compression lap splice in 40 to 100 MPa of compressive strength of concrete. By the proposed equation, the anomaly of lap lengths in tension and compression is got rid of. In addition, the equation has a reliability equivalent to those of the specified strengths of materials.