Mixing Mortarts and Ratios:

 

 

Mixing Mortars and Ratios:

Recommended use of mortar types m/n/s/o/:

Location Building Segment Recommended Mortar Alternative Mortar Exterior, above grade Load-bearing walls Non-load bearing walls Parapet walls N O N Sor M N or S S Exterior, at or below grade Foundation walls, retaining walls, manholes, sewers, pavements, walks and pations S M or N Interior Load-bearing walls Non-load bearing walls N O S or M N From ASTM C 270     Compressive strength: A compression failure in masonry made with weak mortars occurs as a tension failure in the bricks, as they seek to prevent the mortar from being pressed out of the joints. The expression is derived by assuming hydrostatic pressure in the mortar joints, which is the most unfavorable stress distribution with respect to tensile stresses in bricks. The expression is compared with the results of compression tests of masonry made with weak mortars.   Mixing mortars/ Addition of color:There are three primary ways to make mortar: 1.     Portland Cement, Hydrated Lime and Masonry Sand 2.     Masonry Cement and Masonry Sand 3.     Pre-mixed Mortar In class we mixed lime with sand to create the mortar we used for the joints on out brownstone wall. We used a ratio of 3:1 When adding the color it is important to keep track of exactly how much you are adding so that when you make another batch of mortar the color matches exactly. Add the color to the mortar after it is mixed.