Cement Lime Mortar
This kind of mortar has a few of the benefits of both the types of mortars. It has medium strength along with good workability and water retentivity. Generally adopted proportions are Cement: Lime: Sand of 1: 1: 6, 1: 2: 9 and 1: 3: 12. The mix proportion of binder (cement plus lime) to sand is kept as 1: 3.
The mix compressive and proportion strength of a few of the general used mortars are given in Table.
Table : Mix Proportion and Strength of Commonly Used Mortars
|
Sl. No.
|
Mix
|
Min. Compressive
Strength (N/mm2)
|
|
Cemen t
|
Lime
|
Sand
|
|
(1)
|
(2)
|
(3)
|
(4)
|
(5)
|
|
1
|
1
|
0-1/4C
|
3
|
10
|
|
2(a)
|
1
|
0
|
4
|
7.5
|
|
2(b)
|
1
|
1/2C
|
4 .5
|
6
|
|
3(a)
|
1
|
0
|
5
|
5
|
|
3(b)
|
1
|
1C
|
6
|
3
|
|
4(a)
|
1
|
0
|
6
|
3
|
|
4(b)
|
1
|
2C
|
9
|
2
|
|
4(c)
|
0
|
1A
|
2-3
|
2
|
|
5(a)
|
1
|
0
|
8
|
0.7
|
|
5(b)
|
1
|
3C
|
12
|
0.7
|
|
6
|
0
|
1B or C
|
2-3
|
0.5
|
Note 1: A, B, C, implies eminently hydraulic lime, semi-hydraulic lime, and fat lime associatively, as stipulated in IS 712: 1984.
Note 2: While using plain cement sand mortars (Sl. No. 2(a), 3(a), 4(a) and 5(a), it are desirable to involve a plasticizer in the mix to improve its workability.
Note 3: For Mortar at Sl. No. 6, if lime C is used that part of sand should be replaced through some pozzolanic material, for example, burnt clay or fly ash, in sequence to acquire the requisite strength.
Note 4: Strength of a mortar might vary appreciably, depending on angularity, grading and fineness of sand. Quantity of sand in the mix might, thus, be varied where found essential to attain the desired strength.