Masonry Magazine December 1995 Page. 29
HOT AND COLD WEATHER
Continued from Page 13
from cold weather effects. Such changes will affect the aesthetics of the completed structure, as color of mortar may be changed by cement composition.
Materials Receipt and Storage
Materials delivered to the project site should be critically inspected for damage and non-conformance to applicable product specification before acceptance. Significant changes from previously accepted shipments, be it color, presence of cracks, chips, etc., should be recorded and an immediate decision should be made to accept or reject the delivery.
Materials storage should be attentive toward maintaining the products in the "as-recd" condition or upgrading the quality if deemed essential.
Materials accepted below product standards can be upgraded or culled, but both require additional handling. Materials should be stored so the cementitious materials and units are high and dry to prevent water entry from melting snow or ice, rain or ground water. The storage area should not be adjacent a traffic throughway where water or soil could affect the material. Sand should be discharged on a mud slab or some other protective device to avoid native materials being introduced into the mixture.
Production of Masonry Mortar
Masonry mortar production remains essentially similar, regardless of climatic conditions. Temperatures effects are most significant. The temperature of the materials and the machinery for the production of the masonry mortar should be noted with some corrective action if the temperatures become excessive-hot or cold. The primary objective is the production of uniform batches with close control of the quantities of individual materials charged into the mixer. On-site production of the masonry mortar may be accomplished using batch mixers or dry blend mixers.
Batch mixing by shovelsful can be successful. Full bag measures of cement and full or partial bag measures of hydrated lime should be used with mixer capacity selected based on using these measures. To calibrate "shovelsful," a cubic foot measure should be used to establish the number of shovelsful of sand to produce the desired batch volume. Water additions should be by water meter or volume. The volume of mortar in the mixer should be noted and thereafter subsequent batches should be of equal volume. The mortar volume of each batch, thus, becomes a quality control measure.
Dry blend mixers accept the quality control exercised by the supplier of the preblended cementitious materials and mason's sand. Dry sand is combined with cementitious material. The dry blend mixtures may be contained in a silo or bag container. The dry blend is either discharged into a conventional batch mixer or into the throat of an auger mixer. The dry blend mixer receives water additions initially during auger mixing. The dry sand requires production of masonry mortar sufficiently wet to remain workable after sand absorption is satisfied, else tempering will be required before use.
Mortar temperature is not easily controlled. Heated or chilled water can be pumped to the throat of the auger, providing some temperature control. The concept of heating the
Introducing
A Trowel
With A
Definite
Difference...
The
DURA Soft™
Difference.
• Virtually indestructible hard polymer
bumper designed for easy tamping of
brick and block.
• Resilient handle reduces fatigue.
• Integral finger guard protects against
callouses, heat and cold.
* THE BEST SOLID FORGED BRICK TROWEL
AVAILABLE ANYWHERE!
Feel the difference of Marshalltown's exclusive
DuraSoft handle where you shop for tools.
Marshalltown
MARSHALLTOWN TROWEL COMPANY
Р.О. Вох 738 Marshalltown, lowa 50158
Phone: 515/753-0127 Fax: 515/753-6341
MASONRY-NOVEMBER/DECEMBER, 1995 29