What are Mortars..? types of Mortar and it's used in construction
Mortars:
Mortar is an intimate mixture of bonded material, fine aggregate, and water. When water is added to a dry mixture of binding substances and non-critical substances, the binding material develops a property that binds not only unnecessary materials but also the surrounding rocks and bricks. If the cement is bonded material, the mortar is known as cement mortar. Other mortars commonly used are lime mortar and clay mortar. The inactive substance is sand. In this article, first, the non-essential material sand is introduced and then the proportional, mixing, treatment, various properties and use of mortar are explained.
1. SAND:
Sand is a natural product obtained as river sand, canal sand, and pit sand. However, sea sand should not be used for the following reasons.
1. It contains salt so its structure will remain moist. The mortar is affected by flowers and blisters appear.
2. It contains shells and other organic matter, which, after some time, dissolve, reducing the life of the mortar. Sand can be obtained artificially by crushing hard stones. Generally, artificial sand is obtained as a product while crushing stones to obtain jelly (coarse aggregate). Sand is used in mortar and concrete for the following purposes.
- It distributes the paste of the bound material into thin films and allows it to be bonded and spread.
- It fills the space between the building blocks and expands the bound material.
3. It increases the mortar density.
4. It prevents the cement material from shrinking.
5. It allows the carbon dioxide from the atmosphere to reach a certain depth and improve its strength.
6. The cost per unit volume of cement material decreases as this low-cost material increases the mortar volume.
7. The silica of sand helps to form silicate as a result of hard components. The characteristics of good sand are:
- It must be chemically rooted.
- It should be free of organic or vegetable matter.
- It should be salt-free.
- It should have sharp, angular and coarse grains.
- It should be well rated.
- It should be difficult.
2. CEMENT MORTAR:
To prepare the mortar, first, mix the cement and sand mixture thoroughly in a dry state. The water is slowly added and mixed with the shovel. The proportion of sand proposed for different works is as shown in cement.
Curing:
With hydration, the cement gradually gains strength. So it is important to see that the mortar is wet until hydration. The process of ensuring adequate moisture for hydration after laying mortar/concrete is called curing. Spraying water ensures curing. Treatment usually begins 6 to 24 hours after the mortar is used. It should be noted that in the initial period, the water requirement is high for hydration and it gradually decreases. Treatment is recommended for 28 days
Properties of Cement Mortar:
The following are the main features of cement mortar.
1. When water is added to the dry mixture of cement and sand, the hydration of the cement begins and it also binds to the sand particles and surrounding surfaces of the concrete and concrete.
More than
2: 1: 3 compounds are at risk of shrinkage.
3. Well, proportioned mortar provides a poor surface.
4. The lean mix is not able to close the voids in the sand and therefore the plastered surface is unsafe.
5. The strength of mortar depends on the ratio of cement and sand. The strengths obtained with different proportions of cement and sand are shown in the table.
Uses of Cement Mortar
Mortar is used:
1. Tie up masonry units such as stones, bricks, cement blocks.
2. Plaster slabs and walls make them defective.
3. Finishing the walls and concrete works cleanly.
4. To identify the masonry pair.
5. For the preparation of building blocks.
6. As ferro cement works the filler material.
7. Fold the walls and fill the cracks.
8. As filler material in stone masonry.
3. LIME MORTAR:
Pounding:
Hard grinds are made of shelling. The pit is usually 1.80 meters long, 0.4 meters wide and 0.5 meters deep. It has been provided with a layer of bricks or stones. The lime and sand mixed with the desired ratio are kept in a dry pit. Periodically, a small amount of water is added. At each interval, the mix is rounded with a wooden pounder and the mortar is turned up and down. The process continues until the same color and desired consistency is achieved.
Grinding:
This is a good way to mix well. Grinding can be done in a bull-powered grinding mill or in an electric-powered grinding mill. Figure 2.1 shows the grinding mill operating a typical bull. The trench is 3 to 4.5 meters wide, 0.3 meters wide and 0.4 meters deep. A wooden shaft mounted in the center, the width of the stone wheel is only 50 mm to 100 mm lower than the trench. Bell drives this wheel to grind mortar into the trench. The dry mixture is kept in the trench. The water is slowly added and the wheels rolling on the vine are mixed. One worker regularly flips the mix up and down. This method of preparing the mortar requires 6 hours and the mortar can produce about 1.7 m3.
4. MUD MORTAR:
Soil bales are collected and wet with water and allowed to mature for 1 or 2 days. It is thoroughly thawed until it has the desired consistency. Sometimes fibrous material such as dung is added to the mix. This prevents cracks in the plaster. If the plaster is to be used for exterior walls, it is sprayed or painted with bitumen. This is a cheap mortar. Its stability is low. It is commonly used in rural areas to build temporary sheds and affordable housing.
The following are some of the special mortars:
1. Cement clay mortar
2. Gauged mortar
3. Decorative mortar.
Cement Clay
Mortar:
Soil mortar quality can be improved by adding cement to the mix mart. The general ratio of soil to cement is 1: 1. It maintains the economy to some extent and improves the stability of sludge mortar substantially.
Gauged Mortar:
This is the mortar obtained by adding cement to the lime mortar. The normal ratios of cement, lime and sand are 1: 1: 6, 1: 2: 9 and 1: 3: 12. This mortar is to be used within half an hour after cement mixing. Obviously, it is cheaper than cement mortar and the quality is between cement mortar and lime mortar.
Decorative mortar:
These mortars are obtained using colored cement. They are used to give exterior walls a pleasant appearance