|Part 1--Selecting and Mixing Mortar Materials|
MIXING THE MORTAR
Mortar is usually mixed on the job site in portable, mechanical mixers. However, on some small jobs, you can mix mortar by hand.
1-15. Mortar Packaging. The proportions for mortar types are based on volume measurements, and mortar ingredients are packaged by volume. Portland cement is packaged and delivered in 94-pound bags containing 1 cubic foot. Hydrated lime is packaged in 50-pound bags that each contain approximately 1 cubic ft. Sand is delivered by the cubic foot or the cubic yard. A 1:1:6 mortar mix would call for one bag of cement, one bag of lime, and 6 cubic feet of sand. This mixture will equal 6 cubic feet of mortar.
1-16. Machine Mixing. Use the following steps when mixing by machine:
1-17. Hand Mixing. A mortar box is used to mix mortar by hand. It is approximately 5 by 10 feet and can be constructed with 2-inch material (Figure 1-2). The box should be as watertight as possible. Use the following steps when mixing by hand:
1-18. Retempering. If the mortar has become stiff on the mortarboard because of the evaporation of water, you must add water and retemper the mortar to restore its plasticity. Remember the following:
1-19. Discarding. It is sometimes difficult to determine if the mortar should be remixed and used. If in doubt, discard the mortar. Ensure you comply with all environmental laws and regulations when discarding waste. Never use mortar after it has been dropped on the ground or contaminated in any way.
|David L. Heiserman, Editor||
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Revised: June 06, 2015