An engineering evaluation of the concrete deterioration
was authorized by Cemstone Products, Inc., "Cemstone," to determine the cause of
the surface defects of concrete driveways, aprons, alleyways and sidewalks. The evaluation
was a part of the concrete industry's efforts to explain the higher than usual levels of
concrete surface defects in the Twin Cities area during the 1996-1997 construction year.
Jaber Engineering Consulting, Inc. was retained by Cemstone to perform this concrete
evaluation at four selected cities in the Twin Cities area.
JEC performed visual observation, obtained concrete core samples and performed
petrographic analysis on eight concrete samples. JEC then collected related information
about the concrete placement, delivery, weather conditions and salt applications in the
four cities and the Twin Cities metro area.
JEC conducted an engineering analysis and presented Cemstone with a list of the reasons
that had caused the surface defects in the concrete.
As a result of this engineering evaluation Cemstone and JEC developed revised
guidelines for future exterior concrete work to minimize the occurrence of surface defects
in exterior flatwork concrete.