For structural masonry, the following applies. The
defaults for mortar and grout materials in ASTM C
270 and ASTM C 476 are alright for general
construction. Specify Type III portland cement for
cold weather construction, Type II for moderate
sulfate resistance. The blended cements make a gray
mortar; specify portland cement mortar or masonry
cement if white or colored mortar is necessary. Use
only Type S for exterior walls and M below ground.
Do not use Type O in areas of moderate or high
seismic activity. Do not use Type N in areas of
high seismic activity.
Choice of fine or coarse grout depends on width of
grout space and pour height; a table with this
information is in ACI 530/530.1.
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Grout shall conform to ASTM C 476, [fine] [coarse]. Cement used in grout
shall have a low alkali content. Grout slump shall be between 200 and
[250] [280] mm 8 and [10] [11] inches. Minimum grout strength shall be 14
MPa 2000 psi in 28 days, as tested by ASTM C 1019. Grout shall be used
subject to the limitations of Table III. Proportions shall not be changed
and materials with different physical or chemical characteristics shall not
be used in grout for the work unless additional evidence is furnished that
the grout meets the specified requirements. Ready-Mixed grout shall
conform to ASTM C 94/C 94M.
2.10.1
Admixtures for Grout
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NOTE: Admixtures, including air entrainment, may
cause efflorescence and may adversely affect the
strength of the mix or the protection of embedded
steel items.
A grouting-aid admixture may be desirable when
concrete masonry and clay brick units are highly
absorbent to reduce early water loss, promote
bonding, and produce slight expansion to help ensure
complete filling of cavities.
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In cold weather, a non-chloride based accelerating admixture may be used
subject to approval; accelerating admixture shall be non-corrosive, shall
contain less than 0.2 percent chlorides, and shall conform to ASTM C 494/C
494M, Type C. In general, air-entrainment, anti-freeze or chloride
admixtures shall not be used except as approved by the Contracting Officer.
2.10.2
Grout Barriers
Grout barriers for vertical cores shall consist of fine mesh wire,
fiberglass, or expanded metal.
2.11
ANCHORS, TIES, AND BAR POSITIONERS
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NOTE: By definition, ties are connections between
masonry elements, anchors connect masonry to the
SECTION 04200
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