| Mortar & Grout
Masonry mortar is composed of one or more cementitious materials,
clean well-graded masonry sand, and sufficient water to produce
a plastic, workable mixture. Grout for masonry is composed of similar
materials, but is generally mixed to a much more fluid condition.
It may also contain coarse aggregate.
Mortar for masonry joins units into
an integral structure with predictable performance properties. In
- Creates a tight seal between units against the entry of air
- Bonds with joint reinforcement, metal ties, and anchor bolts,
if any, so that they perform integrally with the masonry.
- Provides an architectural quality to exposed masonry structures
through color contrasts or shadow lines from various joint-tooling
- Compensates for size variations in the units by providing a
bed to accommodate dimensional tolerances of units.
Grout for Masonry
Grout is a very fluid combination of water, aggregates, portland
cement (ASTM C 150 and C 1157), blended cements (as specified under
ASTM C 595 and ASTM C 1157), and sometimes fly ash (ASTM C 618)
and admixtures. Depending on the size of aggregates used, grout
is classified as either fine (using only fine aggregates) or coarse
(using a combination of both fine and coarse aggregates). Selection
is based on the size of the space to be grouted.
Grouted reinforced masonry offers expanded structural possibilities
in masonry design. Used in the U.S. since the mid-1800s, it is most
common in single-story and low-rise construction, but can also be
employed in high-rise design.
Mortar & Grout Standards
PCA participates in the American
Society for Testing and Materials committees to ensure appropriate
technical application of cements for use in mortar and grout. The
- C01 Cement
- C11 Gypsum and Related Building Materials and Systems
- C12 Mortars and Grouts for Unit Masonry
- C15 Manufactured Masonry Units
John Melander, Chair of C12, examines how the
ASTM process, people, and technology have shaped C12 standards development
Years of Developing Mortar and Grout Standards for Masonry Construction,”
published in ASTM’s December 2006 Standardization News.
Additional Mortar Information
Additional Grout Information