Masonry Magazine October 1989 Page. 24
about 1½ inches below the top of the last course and consolidated by puddling or vibrating. In high lift grouting, the wall is usually laid up story height before grouting is begun. Grout is then placed in lifts of approximately 4 feet and consolidated, with a 30 to 60 minute delay between successive lifts. Reconsolidation may be necessary after the grout has undergone shrinkage from losing moisture to adjacent masonry units.
Prism tests may be specified for some projects. Test prisms should be representative of the actual composition of the wall, constructed of the same materials and workmanship used in the construction as specified in ASTM E447. Job-site prisms should be made
in a place where they will not be disturbed for 48 hours and where they will be subjected to atmospheric conditions similar to that in the masonry structure. After 48 hours they should be adequately wrapped and protected against jarring while being transported to the testing laboratory for additional curing.
Temporary lateral bracing of concrete masonry walls which may be subjected to high winds is required by many building codes and safety regulations. Walls subject to backfilling should also be temporarily braced until such time as members providing lateral support are in place and anchored to the wall.
Chases and recesses should not be allowed unless shown on the plans; their location, spacing and depth should be checked. Cores and cavities of uncapped walls should be protected from infiltration by rain or snow when work is not in progress.
NATIONAL CONCRETE MASONRY ASSOCIATION
P.O. Box 781, Herndon, Virginia 22070