Unreinforced masonry pilasters
Unreinforced masonry pilasters
(OP)
There were some unexplained cracks in the beam bearing areas of some of the masonry walls of a 2-story building that I designed. Many of these locations were designed with reinforced masonry pilasters (projected or flush-face). The second floor beams are set, the concrete floor has been poured & masonry construction was continuing to the roof level. The walls were x-rayed & the pilasters were found to be lacking vertical rebar or grout, or in some cases, both. This resulted in ALL pilasters being x-rayed. There were instances of discontinuous vertical bars or grout or totally unreinforced masonry throughout the job. The mason has since been fired & the construction manager has told the general contractor that everything must be corrected & to provide a solution. At this point, I am only being asked to review the proposed fixes, but I foresee being asked for my opinion on what to do. Truthfully, I've never encountered this degree of ineptitude & don't really have a "least destructive" course in mind. Has anyone out there been presented with a similar problem? Thanks in advance.






RE: Unreinforced masonry pilasters
I guess the provisions for on site inspectors some clients/building officials require are around for a reason!
Short of having to replace them, is it possible you can sister the columns/pilasters up with either a concrete column or encase them with more masonry? I would guess space limitations will prevent this from being viable but I thought I would throw it out there.
Although I am not familiar with it, some of the rehab guys particularly on bridges and overpasses have started using fiber wrap to strengthen old concrete columns. I do not know if it would be overkill on something like this but it might provide the strength you need.
RE: Unreinforced masonry pilasters
As Pittguy12 indicated, you could consider Carbon-Fiber, but it's not cheap. Rebuilding may be more cost effective.
RE: Unreinforced masonry pilasters
RE: Unreinforced masonry pilasters
RE: Unreinforced masonry pilasters
RE: Unreinforced masonry pilasters
RE: Unreinforced masonry pilasters
Just curious...
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com