R506.2.4.2 Contraction Joints
Concrete slabs-onground shall be provided with contraction joints in accordance with ACI 332 or other approved industry standards.
Contraction joints are not required for slabs onground provided with crack containment measures complying with one of the following:
- Concrete slabs on ground shall contain micro- or macro-synthetic fiber reinforcement. Fiber lengths shall be 1/2 inch to 2.25 inches (13 to 56 mm) in length. Dosage amounts shall be from 0.75 to 3.0 pounds per cubic yard (0.45 to 1.78 kg/m3) in accordance with the manufacturer's recommendations. Synthetic fibers shall comply with ASTM C1116. The manufacturer or supplier shall provide certification of compliance with ASTM C1116 when requested by the building official; or,