This is a detailed guide on cement mortar, after reading this article you will learn cement mortar definition, and you will also understand that what is mortars.
This is a step by step guide from mortar definition to preparation, proportioning, and ingredient mixing.
Cement Mortar Definition.
Cement mortar is the mostly commonly used mortar in the present age. In fact, in all types of construction activities, it is used.
Due to its strong and durable properties.
Preparation of mortar.
The preparation of the cement mortar involves the following three steps.
- Selection of Raw Materials.
- Its Proportioning.
- And Mixing of ingredients.
Selection of raw materials.
The Portland Cement used for making mortar will be pure and undamaged.
Since there are various types of cement available, it must be ensured that only right type will be selected on the basis of the type of construction.
For common construction purposes Ordinary Portland Cement is most suitable. Lime may be used in making composite mortars.
Sand must be of good quality and free from impurities like Oxide of irons, Clay, Dust, etc. It must be thoroughly cleaned before mixing with cement.
Functions of Sand.
- It provides strength.
- It forms bulking in mortars and hence makes it economical.
- It provides resistance against shrinkage and cracking.
Proportioning means the relative volumes of different ingredient that have to be mixed to make cement mortar good.
Or simply the ratio between different materials is called proportioning.
Quality mortars can be prepared only when it is proportioned very carefully.
Following proportions are commonly recommended.
- For ordinary masonry work with brick/stone as a structural unit. ( 1:3 to 1:6 ).
- For reinforced brick work ( 1:2 to 1:3 ).
- For all work in moist situations ( 1:3 ).
- For Architectural work ( 1:6 ).
- For Load Bearing structures ( 1:2 ).
Mixing of Ingredients.
For small construction hand mixing is commonly practiced. And for large-scale construction Machine mixing is performed.
First of all Raw Materials are dry mixed, and then water is added in the desirable amount.
Precaution regarding the use of Mortar.
1. It shall be used within 30 minutes after adding water to the mixture.
Because the setting process starts even within the first hour of its preparation.
So, therefore, it should be used with in the 30 minutes. Otherwise, its strength will be decreased gradually.
2. The structural units, i.e. bricks, and stones must be soaked in water before laying on the walls.
Because the setting of cement requires a good quantity of water.
If dry units are placed on the mortar layer, they will suck water from it very quickly which will cause bad effects on the mixture.
And its strength will be decreased.
3. Further, where mortar is used, the place should be kept wet at least for 7 days.
This process is also Curing. This step is necessary to gain maximum strength.
Read More: Properties of Bricks | A Complete Guide.