![]() ![]() Table 1 (shown on page 2) summarizes the conditions under which ACI 318-11 requires the staggering of lap splices and the stagger distance. Figure 2 - Lap splice stagger options Figure 1 - Staggered lap splices Stagger Requirements of the ACI 318 Code Since 1963, the ACI 318 Code has acknowledged the benefits of staggering lap splices by requiring staggered configurations of bars and splices under various conditions. When considering the longitudinal stagger arrangement of lap splices, there are three basic options, as shown in Figure 2: (A) no stagger, (B) stagger with zero gap, and (C) stagger with a (positive) gap. Review of Staggered Lap Splice Options Staggering of splices is the longitudinal spacing offset of the spliced bars. In Figure 1, note that every other bar is shown lap spliced in the same general location. Figure 1 shows a photo of a staggered lap splice arrangement that has been installed in the top layer of a foundation mat. A staggered arrangement of the lap splices subsequently reduces the localized stresses at each lap location, and lowers the possibility of concrete cracking (splitting) or reduces the crack widths. Staggering the lap splices is sometimes required by the designer, basically for two reasons: (1) to reduce reinforcement congestion in locations where there is a relatively heavy amount of reinforcement, such as in a lower story column of a multi-story building, and (2) to reduce a concentration of bond stresses at the bar ends of the lap splices. Merely move the mouse pointer to the desired cell to view the contents of that particular "comment box".Technical Note Engineering Technical Note ETN-D-2-13 Staggered Lap Splices Introduction Lapped splices are probably the most common means of joining two lengths of reinforcing bars. (Note: presence of a “comment box” is denoted by a “red triangle” in the upper right-hand corner of a cell. This program contains numerous “comment boxes” which contain a wide variety of information including explanations of input or output items, equations used, data tables, etc. The "Rebar Data" worksheet contains tables of reinforcing bar data which include various bar properties, reinforcing bar areas based on spacing, tension development and splice lengths for straight bars, tension development lengths for 90 degree standard hooks, tension lap splice criteria, compression development and splice lengths for straight bars, maximum spacing for column ties, and various plain welded wire fabric properties.Ĥ. A complete table of reinforcing bar development and splice lengths is also created for #3 through #18 bars.ģ. The "Calc Development" worksheet, for a given reinforcing bar size, determines the straight development and splice lengths for a "top" bar and an "other" bar in tension, the straight development and splice lengths for the bar in compression, and the tension development length of the bar as a standard hook, all at one time. This program follows the procedures and guidelines of the ACI 318-11 Building Code, Chapters 12 and 21.Ģ. This program is a workbook consisting of three (3) worksheets, described as follows:Ĭalc Development - Reinforcing Bar Development and Splice Lengthsġ. This version is based on the ACI 318-11 Code. ![]() There is also a worksheet which contains reinforcing bar data tables. The provisions for development and splice lengths are included for high seismic risk applications per ACI 318-11, Chapter 21. Also, the development length for standard hook bars is determined. Specifically, the development lengths and splice lengths for straight bars in tension as well as compression are determined. "REBARS" is a spreadsheet program written in MS-Excel for the purpose of determining reinforcing bar development and splice lengths. "REBARS" - REINFORCING BAR DEVELOPMENT AND SPLICE LENGTHS ![]()
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