Masonry in IBC Code

[TimmyH76]

In the IBC 2003 Code there is a table that summarizes properties of types of mortar. What is the difference and where would I find/use these different types (cement-lime, mortar-cement, and masonry-cement) What is normally used? Thanks.

 

[JAE]

From the NCMA website TEK tips:

TYPES OF MORTAR

Building codes generally specify mortar types as referenced in ASTM C 270, Standard Specification for Mortar for Unit Masonry (ref. 4f). Four mortar types, M, S, N and O are included in this standard. However, Types M, S, and N are typically required by building codes. Building codes also may restrict the use of some mortars for particular applications. For example, empirical design of foundation walls requires Type M or S mortar and glass unit masonry requires Type N or S mortar (ref. 1). In seismic design categories , D, E, and F portland cement/lime or mortar cement mortar Types S or M are required (ref. 1).

Here's a link:

NCMA Link

click on the e-TEKS link on the page and all the TEK documents are yours.

 

[henri2]

Mortar properties indicated in Table 2103.7(2)are utilized when property specifications (as opposed to proportion specifications) govern. Most mortar used in reinforced construction is based on proportion specifications.

As you are aware, the main design referenced standard IBC chapter 21 is based on is the MSJC Code and Specs (ACI 530/530.1). MSJC Code Section 1.13 SEISMIC DESIGN REQUIREMENTS provides the information you seek....and is consistent with the info JAE provided above. Refer to MSJC Code Sections 1.13.6.6 (SDCD), and 1.13.7.1 (SDC E and F).

For SDC A thru C it would then appear that Types M, S, and N cement-lime, mortar-cement, and masonry-cement mortars are permissible for structural masonry depending on amongst other factors, the level of design stresses involved. In the UBC, masonry-cement mortars are not permitted in SZ 2, 3 and 4..and I wonder why this is allowed by the MSJC Code for SDC C. Perhaps the cement industry folks had more clout with MSJC than the lime industry folks.