Masonry Magazine January 1972 Page.18
How to get the roof on before the masonry is complete!
Adjustable Econo-lok makes it possible!
Closing up the building weeks ahead of schedule or ahead of the weather can save thousands of dollars by letting interior trade proceed while masons are still working. It's done like this. The concrete block back-up wall is rapidly constructed using the AA Adjustable Econo-Lok System. After the building shell is completed and roofed, the masons can apply the facing at any time using the Adjustable Econo-Lok loops. Joints do not have to line up. Both walls are locked together securely, yet with ample flexibility for normal building movement. It's fast and sure. This is but one of the many quality AA products shown in the new Masonry Reinforcing Guide. Send for yours. AA Wire Products Company, 6100 South New England Avenue, Chicago, Illinois 60638. Manufactured in Chicago, Dallas, and Toronto, Canada.
All-Weather Masonry Construction
(Continued from page 17)
Illustration 7 shows the effect of calcium chloride additions (0 to 2% by weight of masonry cement-70 pcf) to masonry cement mortars. As will be noted, the plasticity of the mortar increases during the period 0 to 1½ hours after mixing with calcium chloride additions. This retardation and time lapse, which will be referred to again, are followed by accelerated setting and hardening (loss of plasticity).
Illustration 8 shows the effect of calcium chloride on the rate of heat evolved. Non-admixtured portland cement systems show an optimum rate of heat evolved at 8 hours whereas admixtured mortars reach this state in 4 hours and at a greater limit. The same acceleration of heat liberation is noted during the period 0 to 1½ hours, but the differential is not as great. Information regarding the effects of admixtures on concrete and masonry mortars strongly suggest that admixtures should not be used indiscriminately and that they should be evaluated before construction commences; they should perform their intended task during construction or should not be used.
Illustration 9 shows the effect of water-cement ratio on tensile bond and compressive strength. This illustration reflects the many compromises made in establishing specifications and the need for knowing material performance characteristics and the end use of the mixture. Presently ASTM C-270 emphasizes the tensile bond increase with water-cement ratio and stipulates that the maximum water content be used to produce a mortar with workable consistency. This of course contradicts good concrete technology.