appropriate.
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Prepare mortar consisting of one part portland cement, three parts fine
sand which passes a No. 16 sieve, [polymer proportioned as recommended by
the manufacturer, ]and only enough water so the mortar will stick together
in a ball when molded by hand. The water-cementitious materials ratio
shall not be greater than [0.45][ ] by weight. Let mortar set 1/2 hour
prior to placing.
2.3.4
Polymer-Modified Mortar
Polymer-modified mortar shall consist of portland cement, fine aggregate,
water, and polymer. Proportion mortar in accordance with polymer
manufacturer's recommendations. Cured mortar shall comply with the
requirements of paragraph REPAIR MATERIAL PERFORMANCE REQUIREMENTS.
2.3.5
Polymer-Modified Concrete
Polymer-modified concrete shall consist of portland cement, fine and coarse
aggregate, water, and polymer. Proportion concrete in accordance with
polymer manufacturer's recommendations. Cured concrete shall comply with
the requirements of paragraph REPAIR MATERIAL PERFORMANCE REQUIREMENTS.
Polymer-modified concrete for overlays shall conform to ACI 548.4.
2.3.6
Precast Concrete Units
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NOTE: Consider use of harder aggregates and
pozzolan in the design of precast concrete to assure
that the units are durable and abrasion resistant.
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Cement for precast concrete may be Type I portland cement or Type III high
early strength portland cement in accordance with ASTM C 150. If using
Type III cement, make all necessary adjustments pursuant to ACI
requirements to assure the dimensional stability of the units.
2.3.7
Cement-Based Grout
Cement-based grout shall consist of equal parts of Type [I or II], [III]
portland cement [and] sand by dry weight, [and water-reducing admixture,
]thoroughly mixed with water to yield a thick, creamy mixture. The
water-cementitious materials ratio shall not be greater than 0.45 by
weight. The sand shall meet the requirements of the fine aggregate
specified herein, except 100 percent shall pass a 2.36 mm (No. 8) No. 8
sieve.
2.3.8
Ultra-fine Cement Grout
Proportion the ultra-fine cement grout to eliminate shrinkage. The
water/cement ratio shall be by volume and shall not exceed manufacturer
recommendations for the required strength. Proportion the grout to limit
bleed water. The final bleeding in accordance with ASTM C 940 shall be
less than 2%. The expansion in accordance with ASTM C 940 shall be 0 to
5%. Mix the ultra-fine cement using a high shear colloidal mixer.
SECTION 03931
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