Masonry Magazine December 1988 Page. 17
Article 8.2: Measurement of sand by shovel shall not be permitted.
8.3 Mixing Mortars
All cementitious materials and aggregate shall be mixed for at least 3 min and not more than 5 min in a mechanical batch mixer, with the maximum amount of water to produce a workable consistency.
8.4 Retempering
Mortars that have stiffened because of evaporation of water from the mortar shall be retempered by adding water as frequently as needed to restore the required consistency. Mortars shall be used and placed in final position within 2 1/2 hr after initial mixing.
8.5 Climatic Conditions
Unless superseded by other contractual relationships or the requirements of local building codes, cold or hot weather masonry construction practices relating to mortar shall conform to Sections 8.5.1 or 8.5.2.
8.5.1 Cold Weather
Cold weather masonry construction relating to mortar shall comply with the International Masonry Industry All-Weather Council's "Guide Specification for Cold Weather Masonry Construction", Section 04200 Unit Masonry, Article 3.
8.5.2 Hot Weather
When the ambient air temperature exceeds 100°F (38°C) or 90°F (32°C) with a wind velocity greater than 8 m.p.h. (13 Km/hr), mortar beds shall not be spread more than 4 ft (1.2m) ahead of masonry units. Units shall be laid within one minute of spreading mortar.
9. COST OF TESTS
9.1 Unless otherwise specified, the costs of test shall be borne as follows:
9.1.1 If the results of the tests of laboratory prepared mortar show that the mortar does not conform to the requirements of this specification, the costs shall be borne by the seller.
9.1.2 If the results of the tests of laboratory prepared mortar show that the mortar does conform to the requirements of this specification, the costs shall be borne by the purchaser.
9.1.3 If the job specifications require that the construction mortar be sampled and tested for the purpose of quality control, the responsibilities for the costs of such sampling and testing shall be clearly stated in the specifications.
10. SPECIFICATION LIMITATIONS
10.1 BIA Specification M1-88 is not intended and shall not be used to determine physical properties of mortar through field testing.
10.2 ASTM Standard C780 is acceptable for pre-construction and construction evaluation of mortars for non-reinforced and reinforced masonry.
10.3 Tests of Hardened Mortars. There are no accepted standard methods of measuring the composition or physical properties of hardened mortar removed from a structure (see Note 4).
Note 4 When necessary, testing of a wall section or a masonry prism from the completed construction is generally more desirable than attempting to test individual components
TABLE 1
Mortar Proportions by Volume
Mortar
Type
Parts by
Volume of
Portland
Cement
Parts by
Volume of
Hydrated
Lime
Aggregate Ratio
(Measured in
Damp, Loose
Conditions)
M
S
N
O
1
1
1
1
1/4
over 1/4 to 1/2
over 1/2 to 1 1/4
over 1 1/4 to 2 1/2
Not less than 2 1/4
and not more than 3
times the sum of the
volumes of cement
and lime used.
TABLE 2
Property Specification Requirements
Mortar
Type
Average Compressive
Strength at
28 Days, Min. psi
(MPa)
Water
Retention,
min %
Air
Content,
max %
Aggregate Ratio
(Measured in Damp,
Loose Conditions)
M
S
N
O
2500 (17.2)
1800 (12.4)
750 (5.2)
350 (2.4)
75
75
75
75
12
12
148
140
Not less than 21% and
not more than 3½ times
the sum of the separate
volumes of cementi-
tious materials.
Laboratory prepared mortar only (See Note 2).
When structural reinforcement is incorporated in mortar, the maximum air content shall be 12%.
APPENDIX
(Nonmandatory Information)
# A1. Selection of Mortar Type
A1.1 The performance of masonry is influenced by various mortar properties such as workability, water retentivity, bond strength, durability, extensibility and compressive strength. Since these properties vary with mortar type, it is highly important that the mortar type selected for a particular application is the one that best meets the end-use requirements. Table A1 is a general guide for the selection of mortar type for various masonry wall construction. Selection of mortar type should also be based on the type of masonry units to be used as well as the applicable building code and engineering practice standard requirements such as allowable design stresses and lateral support.