Using mechanical splices allows the option of larger diameter rebar in a smaller column while minimizing congestion. Working with “small” diameter reinforcing bars may require the use of larger column dimensions to accommodate a greater quantity of bars. The larger the rebar size, the more cost efficient mechanical couplers become in the overall cost of a project. This means a more material-efficient design for engineers, reducing rebar lengths while improving structural integrity and minimizing the total amount of steel needed for a project. Mechanical couplers allow the butt splicing of rebar, without the need to overlap. When comparing the cost of using mechanical couplers against lap splicing, there may be several hidden costs in lap splicing that should be considered for a true apples to apples comparison With all of those considerations, each design choice has a unique tradeoff with all of the other design choices. In a previous post, we considered the basic design considerations of a lap splice design compared to mechanical splices, such as the grade of steel, surface condition of the bar, size of bars, grade of concrete, position of the splice with respect to concreting and design loads. In this blog, we will look at some of the maybe not-so-obvious advantages of using mechanical rebar splices versus lap splicing when comparing the total installed cost for a project. More and more engineers are specifying mechanical rebar connections over lap splices because mechanical connections afford a reliability and consistency that can’t be found with lap splicing. But as many structural engineers, architects and specifiers have discovered, lap splicing has very few advantages and quite a few disadvantages when compared to mechanical couplers. The Guide is best used as a complement document to design and detailing standards publications, creating value by offering detailed insights specific to welded wire reinforcement.For many years, lap splicing has been the traditional method of connecting reinforcing bars. It explains by example why (a) the structural Engineer-of-Record (EOR) needs no proprietary-like knowledge in order to implement WWR into their contract drawings, and (b) the protocol-in-use for reinforced concrete design and detailing need not be overhauled in order to accommodate WWR usage. The Welded Wire Reinforcement Design and Detailing Guide ( “The Guide”) provides contractors and designers a comprehensive benchmark for the incorporation of WWR into contract documents used on site. WWR.7– Welded Plain Wire Reinforcement Lap Splice ScheduleĪ consolidated general reference for welded plain wire reinforcement lap splices calculated based on contribution from the welded intersections only. WWR.6 – Welded Deformed Wire Reinforcement Lap Splice ScheduleĪ consolidated general reference for welded deformed wire reinforcement lap splices calculated based on contribution from the deformed wire surface only. WWR.5 – Welded Deformed Wire Reinforcement Lap Splice Detail for Elevated Two-Way SlabĪ suggested lap splice reference for WDWR in structural elevated slab applications. WWR.4 – Welded Deformed Wire Reinforcement Lap Splice Detail for Structural Ground-Supported SlabĪ suggested lap splice reference for WDWR in structural slab-on-ground applications. WWR.3 – Welded Plain Wire Reinforcement Lap Splice Detail for Structural Ground-Supported SlabĪ suggested lap splice reference for WPWR in structural slab-on-ground applications. WWR.2 – Welded Plain Wire Reinforcement Lap Splice Detail for Slab-on-GroundĪ suggested lap splice reference for WPWR in nominal slab-on-ground applications. The AASHTO LRFD Bridge Design Specifications Quick Reference provides for the design professional a compilation of code section references categorized in a cheat-sheet type format.Īn illustrative representation of the current ASTM A1064 geometric and dimensional tolerances for WWR manufacture. The ACI 318-19 Quick Reference provides for the design professional a compilation of code section references categorized in a cheat-sheet type format.ĪASHTO LRFD Bridge Design Specifications (9th Edition | 2020): Quick Reference for Welded Deformed Wire Reinforcement The ACI 318-19 Primer is a quick and handy “cheat sheet” for the design professional, highlighting code provisions relevant to the implementation of WWR in structural design.ĪCI 318-19: Quick Reference for Welded Deformed Wire Reinforcement ACI 318-19: Table 20.2.2.4(a) – Deformed Wire and Welded Deformed Wire ReinforcementĪ consolidated version of ACI 318 Table 20.2.2.4(a) is provided here, showing the variety of structural applications and usage of deformed wire and welded deformed wire reinforcement.ĪCI 318-19: A Welded Deformed Wire Reinforcement (WWR) Primer
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