ACI Releases 318-11 Building Code
The American Concrete Institute has released ACI 318-11, “Building Code Requirements for Structural Concrete and Commentary.”
The ACI 318-11 standard is for all concrete design, construction, inspection, repair, and research professionals. It contains the latest code requirements for concrete building design and construction alongside the corresponding commentary, and includes many improvements and changes from the 2008 edition.
“Engineers, architects, contractors, specifiers, building officials, students, and professors all rely on and regularly use ACI 318,” said Ron Burg, executive vice president of ACI. “Members of ACI Committee 318 have volunteered thousands of hours to ensure that necessary updates have been made to this 2011 edition, dedicated to enhancing the safety of concrete structures.”
Following is a summary of key changes in ACI 318-11:
· Design, installation, and inspection requirements for adhesive anchors are now included. Nominal strengths are defined for adhesive anchors in cracked and uncracked concrete and for adhesive anchors subject to sustained loads. The code includes criteria for overhead installation of adhesive anchors and requires the certification of adhesive anchor installers for certain installations. The seismic requirements for anchoring to concrete have also been revised.
· Reinforcement detailing for seismic applications have been enhanced. These new requirements include reinforcement detailing for distinct segments of special structural wall systems, detailing of horizontal bars at special boundary elements, and tightened confinement details for flexural hinge regions of large beams.
· Test methods ASTM D516 and D4130 are referenced to determine the concentration of dissolved sulfates in water, brackish water, or seawater, and ASTM C1580 is referenced to determine percent sulfate by mass in soil.
· Newly available deformed bar types are integrated into appropriate provisions. Grade 80 deformed bars conforming to ASTM A615 or A706 are allowed for non-seismic applications. Zinc and epoxy dual-coated reinforcing bars per ASTM A1055 are also now recognized.
· Test records for determining standard deviation for a mixture design may now be up to 24 months old. Also, testing agencies performing acceptance testing of concrete are now required to comply with ASTM C1077.
· Detailing requirements for ties for circular columns are more rigorously defined and minimum reinforcement for deep beams have been added.
· Detailing requirements of temperature and shrinkage reinforcement for post-tensioned slabs have been revised.
· Factored load combinations now fully conform to ASCE 7-10.