1909A Modifications to Aci 318 — 2025 California Building Code

The text of ACI 318 shall be modified as indicated in Sections 1909A.1.1 through 1909A.1.16.

1909A.1.1 ACI 318, Section 4.12.2.2. Modify ACI 318, Section 4.12.2.2 by adding the following:

Where prestressed concrete elements are restrained from movement, an analysis of the stresses in the prestressed elements and loads in the adjoining structural system induced by the above-described effects shall be made in accordance with PCI Design Handbook.

1909A.1.2 ACI 318, Section 4.12.2.3. Modify ACI 318, Section 4.12.2.3 by adding the following:

For prestressed concrete members with recessed or dapped ends, an analysis of the connections shall be made in accordance with procedures given in PCI Design Handbook.

1909A.1.3 ACI 318, Section 9.6.1.3. Modify ACI 318, Section 9.6.1.3 by adding the following:

This section shall not be used for members that resist seismic loads, except for either of the following conditions: 1. Foundation members for one-story wood-frame or one-story light steel buildings. 2. Foundation members designed for seismic load combinations including the overstrength factor. [OSHPD 1 & 4] The A s provided shall not be less than that required by 1.2 times the cracking load based upon f r defined in Section 19.2.3.

1909A.1.4 ACI 318, Section 11.2.4.1. Replace ACI 318, Section 11.2.4.1 as follows:

11.2.4.1 – Walls shall be anchored to intersecting elements such as floors or roofs; or to columns, pilasters, buttresses, of intersect- ing walls and footings with reinforcement at least equivalent to No. 4 bars at 12 inches (305 mm) on center for each layer of reinforcement.

1909A.1.5 ACI 318, Section 11.7. Add Section 11.7.6 to ACI 318.1 as follows:

11.7.6 – Reinforcement. Perimeters of precast walls shall be reinforced continuously with a minimum of one No. 5 bar extending the full height and width of the wall panel. Where wall panels do not connect to columns or other wall panels to develop at least 75 percent of the horizontal wall steel as noted below, vertical perimeter bars shall be retained by hooked wall bars.

A continuous tie or bond beam shall be provided at the roof line either as a part of the roof structure or part of the wall panels as described in the next paragraph below. This tie may be designed as the edge member of the roof diaphragm but, in any case, shall not be less than equivalent to two No. 6 bars continuous. A continuous tie equivalent to two No. 5 bars minimum shall also be provided either in the footing or with an enlarged section of the floor slab.

Wall panels of shear wall buildings shall be connected to columns or to each other in such a manner as to develop at least 75 percent of the horizontal wall steel. No more than half of this continuous horizontal reinforcing shall be concentrated in bond or tie beams at the top and bottom of the walls and at points of intermediate lateral support. If possible, cast-in-place joints with rein- forcing bars extending from the panels into the joint a sufficient distance to meet the splice requirements of Section 25.5.2, for Class A shall be used. The reinforcing bars or welded tie details shall not be spaced over eight times the wall thickness vertically

nor fewer than four used in the wall panel height. Where wall panels are designed for their respective overturning forces, the panel connections need not comply with the requirements of this paragraph.

Exception: Nonbearing, nonshear panels such as nonstructural architectural cladding panels or column covers are not required to meet the provisions of this section.

1909A.1.6 ACI 318, Section 11.9. Modify ACI 318 by adding Section 11.9 as follows: