Masonry investigation at Construction Engineering Research Laboratory

The Construction Engineering Research Laboratory (CERL) and the Construction Materials Laboratory buildings at the University of Illinois at Urbana-Champaign suffered from chronic cracks in the exterior brick walls since the construction of the buildings in 1969. The brick façade had been repaired a couple of times but cracks re-appeared. The University hired Fehr Graham to investigate the cause of cracking and suggest recommendations for permanent repairs.

Our team discovered typical crack patterns that included horizontal cracking aligned with the top of windows and stepped crack patterns near the building's expansion joints. There was also interior damage because the corners of the walls being pushed outward.

The exterior walls of both buildings were masoned using concrete blocks and clay bricks. While concrete blocks tend to shrink because they do not hold moisture, clay bricks absorb moisture, causing them to expand. Insufficient and faulty expansion and contraction joints resulted in shifting and cracking.

The University took our advice. Workers removed the exterior brick and brick pillars to saw through control joints to create clearance on the side of the bricks. The brick pillars were reconstructed and foam expansion filler was added on each side of the pillars. Finally, a sealant was installed in the new cut and expansion joints.

As of today, the buildings have not shown signs of new cracking.

AT A GLANCE
» Inspected and documented cracks.
» Reviewed plans.
» Reviewed building construction details and codes.
» Provided evaluation report with proposed repair recommendations.