McKinney ISD’s stadium and community event center is faced with “excessive, unsightly” concrete cracking at the visitor’s concourse, according to the second of three reports by Nelson Forensics, an investigative and forensic engineering organization. Cracks at the approximately $70 million stadium are located in the home concourse, visitor concourse and home and visitor concourse lower bowl wall. These areas were brought to the attention of Manhattan Construction and Stantec in January. Nelson’s latest report, which was completed June 13 and released to Community Impact Newspaper July 30, focuses on the visitor’s concourse at the stadium. The district hired Nelson in April to review areas of concern. “The cracking at the visitor concourse does not presently compromise the strength of the slabs or otherwise pose a life safety concern,” according to the report. “However, the cracks will allow water to migrate into the concrete cross section and influence corrosion of the reinforcing steel. The cracks within the fields of the flatwork planes will ravel, or widen, at their top surfaces, ultimately causing material loss and potential tripping hazards. Vehicular traffic from lifts and carts will accelerate these distress manifestations. The observed cracking poses both serviceability and durability concerns.” During a May meeting MISD CFO Jason Bird said long-term durability and low maintenance are paramount at the stadium and community event center, which is supposed to be used for more than 50 years. The cracking is a result of three factors, according to the report:
- An excessive addition of water added to the concrete mixture during construction which caused excessive drying shrinkage of the concrete;
- substantial reduction in the concrete cross section due to the inclusion of drag reinforcement at the east-west pier lines; and
- insufficient steel reinforcing to control shrinkage cracking.
