Masonry Magazine June 1976 Page. 13
3. Cementitious Material.
This should be type I or type III portland cement conforming to ASTM C 150. Masonry cements or any other proprietary mixes should not be used.
4. Workability Additive.
This is a filler (plasticizer) in the form of pulverized ground limestone or marble dust, meeting the following sieve requirements and be approved by Amspec Inc. for chemical composition.(1)
Sieve Size Percent Passing
100 100
200 94
325 86
400 82
5. Water.
Water must be free of acids, impurities and be potable.
Mortar Proportions.
Below are Dow's suggested field proportions (measured by volume) of the required ingredients. It is important, as with conventional mortar, that they be controlled and accurately proportioned for consistent results.
Sarabond Brand 4 gal
Mortar Additive 3½ cu ft
Mason Sand 2½-3½ cu ft
Allowable Range
Portland Cement 1 bag (94 lb)
Type I or III.
Workability Additive 1 bag (50 lb)
Water As required up to a maximum of 4 gal
Volume of Mix Volume of Sand
PHYSICAL PROPERTIES OF BRICK SARABOND ASSEMBLAGES
During its development and throughout the early field applications of Sarabond modified mortar, much research and testing were performed, both by Dow and BIA. These tests were made to determine the physical properties in order to be able to predict the field performance of assemblages of Sarabond mortar and brick. They included: flexural strength, axial strength, shear strength, fire resistance, absorption, aging, freezing and thawing, and chemical resistance. In all cases, the test specimens were a nominal 4 in. in thickness.
Flexural Strength.
The flexural strength or modulus of rupture is a measurement of a wall's tensile strength capacity. This is measured by the full scale transverse wall tests as outlined in ASTM E 72 (see Fig. 3), or by simple flexural beam tests as outlined in ASTM E 518 (see Fig. 2). The flexural beam test, as discussed earlier, is used as an initial acceptance test once a particular brick is selected for a project. Figures 7 and 8 show allowable wind loads on non-loadbearing high-bond walls for various wall heights and thicknesses, based on a minimum average ultimate flexural tensile strength, f', of 360 psi. Curing should follow the high-bond additive manufacturer's specifications for these tests.
Axial Strength.
Axial strength is a measurement of the wall's ability to carry compressive loads. Many full scale 4-in. walls were tested with various slenderness ratios to determine a safe allowable strength. In Table 2, the effect of the various slenderness ratios on the ultimate compressive strength is shown. Figure 5 is a refinement of these data in which walls with both ends pinned and walls with one end pinned and one end fixed were tested and their comparative strengths put in design form. The following formula is recommended for allowable axial compressive stress:
Fa = C(0.25 fm)
where:
Fa = allowable axial compressive stress (see Table 1),
C = slenderness reduction factor (see Fig. 5),
fm = ultimate compressive brick masonry prism strength.
FIG. 3
Transverse Wall Test