Page 99 - Design of Reinforced Masonry Structures

MASONRY UNITS: APPLICATIONS, TYPES, SIZES, AND CLASSIFICATION 2.51

Use of glass block units is not permitted after being removed from an existing panel
according to the MSJC-08 Code, although 2009 IBC, in general, permits reuse of second
hand units if they conform to the requirement of new units.

2.12 MORTARLESS BLOCK SYSTEMS

Conventional or in-place masonry construction uses masonry units which are bonded
together with mortar. Mortarless block systems are a new generation of concrete masonry
units that symbolize innovation by the masonry construction industry. As the terms
“mortarless block systems” indicates, these systems use concrete blocks that stack directly
on one another without mortar. They are bonded together with materials trowelled onto or
poured inside the wall. It is claimed that this system of installation requires less skill, and
construction time is considerably reduced [2.53].
While new mortarless block systems continue to develop, several proprietary systems
are already in use by the masonry industry. They have been used for building houses, high-
rise apartment buildings, and industrial construction. A few mortarless systems reported in
the literature are [2.53, 2.54]:
1. Azar dry-stack block system, developed by Azar Group of Companies, Windsor, ON,
Canada.
2. Haener block system, developed by Haener Block Co., San Diego, CA, USA.
3. IMSI block system, developed by Insulated Masonry Systems Inc., Orem, Utah, USA.
4. Sparlock system, Sparlock Technologies, Inc., Montreal, Quebec, Canada.
5. Durisol block system, developed by Durisol Inc, Hamilton, ON, Canada.
6. Faswell block system, developed by the K-X Industries Inc., Windsor, SC, USA.

One or more of these systems can be modified to suit the desired applications. These
innovative systems actually form a part of concrete home building systems that are finding
wider acceptance, and more competitive in many more market segments than before. A
detailed description of these systems can be found in the literature [2.53].

2.13 PREFABRICATED MASONRY

Prefabricated masonry evolved as a logical innovation from the experience gained in pre-
fabricated building elements which have been used by the construction industry for a long

time. The early development of prefabricated masonry took place in Europe shortly after
World War II, in France, Switzerland, and Denmark. It evolved as an answer to the desperate
need in Europe for fast and economical rebuilding with available manpower and materials.
In the United States, development of prefabricated masonry panels started in the 1950s. The
brick industry, through its research arm, the Structural Clay Products Research Foundation,
(SCPRF), now the Engineering and Research Division of the Brick Institute of America
(BIA), developed the SCR building panel. Although, this system, using special units, rein-
forcing, and grout backing, was successful on several projects in the Chicago area, it did
not achieve wide acceptance by the masonry industry. However, several developments in
the 1960s greatly affected the rapid growth of demand and the manufacturing capabilities
for prefabricated unit masonry. A major trend which greatly increased the market potential
for prefabricated masonry as well as for other materials and equipment was the “systems