A while back I listed several ASTM standards that have been revised in the past year, and asked our Industry members to let me know what those changes mean. Tom Richardson, CSI, called right after specifics was delivered; his response is printed below.

If each one of our Industry members were to review just one or two reference standards, we could build a small library for the benefit of all our members. So dig into those standards! Thanks again to Jack Lindeman, CSI, CCS, of the Mpls.-St. Paul Chapter, for developing an extensive list of standards that have changed.

Mortar Cement

by Thomas Richardson, CSI

In the spring of 1990, mortar cement was added to UBC 21-14. Mortar cement is used to make types M, S, and N masonry mortar as defined in UBC 21-15 and ASTM C270. The mortar cement standard, ASTM C1329-96 was approved in June 1996. Mortar cement is now available in eight states, including Minnesota.

Mortar cement differs from masonry cement in several ways. Flexural bond strength is higher, and there are tighter standards for air content, permitted constituents, quality control, and disclosure requirements. Its purpose is to provide structural performance equivalent to that of Portland cement/lime mortar.

ASTM E514-90 water permeance testing indicates that mortar cement is comparable to Portland cement/lime mortars in minimizing wall leakage.

This high-performance mortar has notable plastic properties. It has excellent board life and workability, its air content is less than 12%, and it exceeds the minimum water retention requirements. Hardened, it has excellent flexural bond, uniform color, and achieves required 28 day compressive strengths in 7 days.

Mortar cement also provides the advantages of uniform proportioning associated with pre-blended cements. Performance at the mortar/unit interaction level compares favorably with other mortar compositions.

For more information, call the Lafarge Corporation, or visit its website at www.lafargenorthamerica.com/.

 

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