Mortar is a paste formed by the addition of water to the mixture of binding material and fine aggregate. It plays vital role in constructions. There is different type of mortars available and every mortar should have its own advantages and disadvantages.
But mortar with good qualities and properties will have more advantage over the other. Here we will discuss about the qualities and properties required for the good mortar mix.
Qualities of a Good Mortar
Qualities of good mortar mix is as follows.
- Water retention
1. Strength of Mortar
A mortar is said to be good in strength only after its hardening. But use of good quality material in good proportions lead to good strength mortar. However, along with the mortar, building units are also be of good quality then only the structure will stand for long period.
When it comes to preparation of good strength mortar, the sufficient cement content should be used. Well graded fine aggregate should be used. Water content should not be more than required amount.
The consistency of a mortar is indicated by the term mobility. The consistency is categorized into different types as stiff, dense, loose, fluid etc. Mobility of mortar is dependent of composition of mortar ingredients. Mortars of different consistencies are used for different works.
The ability to Place a mortar layer economically on the surface of structure is called Placeability of mortar. Thinner and uniform is the layer minimum is the cost. The good quality mortar layer should also develop good bond with surface. Placeability purely depends up on consistency or mobility of the mortar.
4. Water Retention
A good quality mortar has strong water retention capacity. A mortar should not lose its water content especially during transportation. If the water gets separated from the mix, then it is difficult to get harden and strength of mortar also reduced. The mortar cannot develop strong bond with the surface without sufficient water in it. Several types of plasticizers are available for enhancing water retention of mortar.
Properties of Good Mortar
When a mortar is said to be good mortar it should obey the following properties:
- The mortar should have sufficient adhesive property to develop strong bond with masonry units.
- The mortar should be water proof and it should not allow water through it in external walls during rainy season.
- The mortar should be long-lasting.
- The mortar should be economical and easily placeable.
- The mortar should be easily workable.
- A good mortar should develop designed stresses after hardening.
- The mortar should not allow cracks near the joints and it should maintain good appearance for longer periods.
- The mortar should take less time to set which results speedy construction.
- The properties of materials which comes into contact with mortar should not be affected by it.