The clear spacing between ties must be at least (4/3) d agg. Tie spacing requirements for reinforced concrete columns in buildings assigned to SDC A and B are given in Figure 3.
When using the allowable stress design method, develop-ment of wires in tension is determined using Equation 2 (see Table 2). butt weld all splices at perimeter angle refer to attachment details refer to attachment details refer to attachment details refer to attachment details cut high hat in field (by erector) 1' min 1' min deck units over flange. When noncontact lap splices are used, the bars must be spaced no farther apart than one-fifth the required length of lap nor more than 8 in. metal deck shall be continuous over a minimum of 2 spans 4. As per ACI 318, the tension lap splices are classified into two classes Class A and Class B ( Table R12.5.2, ACI 318) for which the lap length are as follows: Class A Splice: Lap Length ls 1.0 ld. Requirements for columns with tie reinforcement are given in ACI 318 Sections 10.7.6 and 25.7.2, and standard hook dimensions for ties are given in ACI Section 25.3.2. end laps to occur at supports only, minimum lap 2' 3. These lap splices also must be located away from the ends of the column where spalling of the concrete shell surrounding the transverse reinforcement is likely to occur due to a seismic event (ACI 318 Section 18.7.4.3). The type of lap splice that must be used depends on the stress in the longitudinal bars due to the factored load combinations (see ACI 318 Section 10.7.5.2).įor columns that are part of special moment frames in buildings assigned to SDC D, E, or F, lap splices must be tension lap splices and located within the center half of the column length. Similar tables can be created for other tie bar sizes and circular longitudinal bar arrangements.įor columns in ordinary moment frames in buildings assigned to Seismic Design Category (SDC) A or B, or in intermediate moment frames in buildings assigned to SDC C, lap splices of the longitudinal bars are permitted to occur immediately above the top of the slab, which is the preferred location for ease of construction ( Figure 2). The column face dimensions have been rounded to the nearest inch. To facilitate the selection of the longitudinal bars, Table 2 contains the minimum face dimension of rectangular tied columns with normal lap splices based on the minimum spacing requirements assuming 1.5-inch clear cover to #4 ties. Minimum face dimension (inches) of rectangular tied columns with normal lap splices.
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