From: Roger Turk <73527.1356(--nospam--at)compuserve.com>
Date: Fri, 4 Jun 1999 19:34:27 -0400
If you read the specs on masonry cements, masonry mortar, etc., you will
probably be surprised, as I was, to learn that portland cement is **NOT** a
required ingredient! Masonry cement and masonry mortar are proprietary with
the manufacturer and as long as they meet the mechanical requirements of the
specs and the strength requirement, they can contain anything. Table 21-11-A
of UBC Standard 21-11 for Cement, Masonry in the 1997 UBC (Volume 3) lists
only requirements for:
Time of Setting
Air Content of Mortar
Water retention, Flow after suction
My specs will not allow use of these, nor will it permit use of lime
Hope this helps.
A. Roger Turk, P.E.(Structural)
Robert Rollo wrote:
>>is there chemical difference between portland plus lime and masonry cements?
or are masonry cements simply premixed with the lime?
seems like i had heard once (with no confirmation) that portland plus lime is
better than allowing masonry cements, primarily due to the leaching of salts
responsible for efflorescence.
we typically spec ASTM C270 proportion spec for S with portland and lime for
have i lost my mind on the efflorescence and should i be performance
spec'ing and forget the efflorescence issue ?
thanks in advance.<<