![]() It is preferred for rebar congestion wherein greater moment strength is required. Welded splicing is used for special conditions splicing of rebars with a diameter greater than 36mm. This method of splicing is done by welding so that the stresses are transferred by weld. Today, a range of threaded and non-threaded mechanical splices are available to ensure a precise, reliable connection. The mechanical joints will not create any steel congestion as the lapping of bars is eliminated. Mechanical splices maintain load path continuity of the reinforcement. A continuous reinforcement bar is obtained through this coupler splicing. ![]() The mechanical splices also allow structural designers to achieve an ideal balance of steel and concrete by eliminating the additional rebar lap zone by meeting building code requirements in many areas. Mechanical splicing methods are being adopted in project sites due to their flexibility of use in congested reinforcement places at construction joints. Mechanical splices join rebar end-to-end, providing many of the advantages of a continuous piece of rebar. The method is used to create connections between two pieces of rebar that enable the bars to act like continuous lengths of rebar. In this method of splicing, the bars in direct contact are mechanically connected through sleeves or other similar devices. When two different diameters of bars have to be lapped, the lap length should be calculated based on the diameter of the smaller bar. Hooks are also to be provided at the end of the tension bars. Tension splices should be enclosed in spirals made from 6mm bars with a pitch not more than 100mm. in flexural tension should not be less than 30 times the diameter of the bar of the full development length Ld as calculated. The total lap length of bars including bends, hooks, etc. The length of a lap splice varies with concrete strength, type of concrete, the yield strength of the reinforcing bars, bar size, bar spacing, concrete cover, and the number of ties or stirrups. Where reinforcing bars of two sizes are lap-spliced in tension, it is better to use the larger of the tension lap splice length for the smaller bar. Lapped sections of non-contact lap splices do not touch and are permitted in practice provided the distance between lap sections meets the specified code requirements. The lapped sections of contact lap splices are wired together. There are two types of lap splices: contact lap and non-contact lap splices. This helps transfer loads properly throughout the structure. This type of splicing is done using a lap splice to join two pieces of rebar overlap to form a continuous reinforcement. In India, the requirement of reinforcement bar splicing is covered in IS456 cl.25.2.5.ĭifferent methods of Splicing Reinforced Bar When the length of the reinforcement bar has to be extended in reinforced concrete structural member splicing is used. The two bar diameters provide space for the concrete to go in, around, and between the bars and increase the strength. The method involves joining the bars together and overlapping them, but leaving at least two bar diameters between the bars. Note that both the shear and moment diagrams resemble your illustration.The method used to join the reinforcement bars, so that the force is transferred effectively from one bar to the other is called splicing. I made the semi-graphical solution shown below. Redraw the shear and moment diagrams for the beam. Redraw the free body diagram with the UDL and the point loads on the beam where each of the four fasteners are located. Moment at the splice location is 49.0 kip-ft.įor simplicity, the spice plates are connected to the beam with two fasteners on each side of the splice location.Įach pair of fasteners form a couple resisting 49.0 kip-ft. The splice is located 7' from the left end. An example is clearer than words:Īssume a 21' long spliced beam with simple supports, supporting a UDL of 1 kip/ft. Assume no friction between beam and splice plates. The couple on each side of splice have opposite signs. On both sides of splice location, the fasteners form couples each couple resists moment equal to what would have been present in the beam at the splice location. Sturctee - The beam at the splice location can not resist moment.
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