Masonry Magazine January 1976 Page. 23
BIA Technical Notes
on Brick Construction
Brick Institute of America 1750 Old Meadow Road, McLean, Virginia 22101
PREFABRICATED BRICK MASONRY
INTRODUCTION
The desire of the construction industry to minimize the use of on-site labor has brought about prefabrication of building components. The masonry industry is one of the later entrants into the prefabrication field. Methods of prefabrication of masonry have been developed by several segments of the brick industry: mason contractors, brick manufacturers, equipment manufacturers and others closely associated with the industry.
This series of Technical Notes deals with the prefabrication of brick masonry, including techniques, methods, controls and a suggested standard specification. This, the first of the series, will cover the history, method of prefabrication, types of mortars used, advantages, disadvantages and present applications of prefabricated brick masonry.
There are several recent developments which make prefabrication of brick masonry possible. The most important is the development and acceptance of a rational design method for brick masonry. Other factors, such as research with new and improved brick units and mortars, have aided the rapid progress in the prefabrication process.
This Technical Notes deals only with prefabricated brick masonry using full size brick units. Prefabricated elements of thin brick facing units, in conjunction with concrete, fiberboard or other backing, are not included because they are usually proprietary items and are, therefore, beyond the scope of this Technical Notes.
HISTORY AND DEVELOPMENT
Prefabrication of brick masonry had its early development during the 1950s in France, Switzerland and Denmark. Prefabrication in the U.S. and other foreign countries began in the early to mid '60s.
The Structural Clay Products Research Foundation, now a part of the Brick Institute of America, Engineering & Research Division, as early as the mid 1950s developed a prefabricated brick masonry system. This system, known as the "SCR building panel**, was used in construction of several structures in the Chicago area which are still in service today.
The ability to design brick masonry using rational engineering criteria has made prefabrication feasible. *Reg. U.S. Pat. Off.. SCPI (BIA), Pat. No. 3,248,836 40 Oct./Nov. 1973
This engineering design method is based upon much research done by SCPRF and others. This research is continuing today in search of improved methods for design and broader applications of brick masonry.
Other factors have influenced the development of prefabrication, such as improved quality control in the manufacture of masonry units and the development of new units. The predictability of performance of portland cement-lime mortar has also been a factor. The development of several high-bond mortar additives primarily for use in prefabrication has contributed to prefabrication development and has also found a place in conventional masonry work.
Most of the early methods of panelization were attempts to mechanize the bricklaying process to produce standard panels, using unskilled labor. Later trends, especially in the United States, have been toward the retention of skilled labor using conventional masonry construction practices and devising various means to increase mason productivity.
There are several different methods or systems of prefabrication being used in the U.S. today. Several of these are available on a local franchise basis. Other systems employ mechanized equipment which may be purchased outright, while still others are not patented but are merely methods of prefabrication developed by individual manufacturers or mason contractors.
FABRICATION METHODS
There are several manufacturing methods presently being used in brick masonry prefabrication. There are five general factors which affect the manufacturing process and properties of prefabricated brick masonry. These factors are:
1. Hand-laying
2. Casting
3. Equipment
4. Masonry Units
5. Mortar and Grout
Hand-laying. The hand-laying method of prefabrication is achieved in the same manner as conventional in-place masonry, except it is accomplished in an area removed from the final location of the masonry element. The laying may be done using any of the equipment, units or mortar described in the paragraphs which follow. This method is particularly adapted to a mason contractor prefabricator since his