GLASS - STRUCTURAL BUILDING MATERIALS BASICS AND TUTORIALS

GLASS - STRUCTURAL BUILDING MATERIALS BASIC INFORMATION
What Are The Uses Of Glass In Construction?


Silica is the main constituent of glass. But it is to be added with sodium potassium carbonate to bring down melting point. To make it durable lime or lead oxide is also added.

Manganese oxide is added to nullify the adverse effects of unwanted iron present in the impure silica. The raw materials are ground and sieved. They are mixed in specific proportion and melted in furnace. Then glass items are manufactured by blowing, flat drawing, rolling and pressing.

Important Properties of Glass
1. It absorbs, refracts or transmits light. It can be made transparent or translucent.
2. It can take excellent polish.
3. It is an excellent electrical insulator.
4. It is strong and brittle.
5. It can be blown, drawn or pressed.
6. It is not affected by atmosphere.
7. It has excellent resistance to chemicals.
8. It is available in various beautiful colours.
9. With the advancement in technology, it is possible to make glass lighter than cork or stronger than steel.
10. Glass panes can be cleaned easily.

Types of Glass
The glass may be broadly classified as:
1. Soda-lime glass
2. Potash lime glass

3. Potash lead glass
4. Common glass and
5. Special glasses.

1. Soda Lime Glass: It is mainly a mixture of sodium silicate and calcium silicate. It is fusible at low temperature. In the fusion condition it can be blown or welded easily. It is colourless. It is used as window panes and for the laboratory tubes and apparatus.

2. Potash Lime Glass: It is mainly a mixture of potassium silicate and calcium silicate. It is also known as hard glass. It fuses at high temperature. It is used in the manufacture of glass articles which have to with stand high temperatures.

3. Potash Lead Glass: It is mainly a mixture of potassium silicate and lead silicate. It possesses bright lustre and great refractive power. It is used in the manufacture of artificial gems, electric bulbs, lenses, prisms etc.

4. Common Glass: It is mainly a mixture of sodium silicate, calcium silicate and iron silicate. It is brown, green or yellow in colour. It is mainly used in the manufacture of medicine bottles.

5. Special Glasses: Properties of glasses can be suitably altered by changing basic ingradients and adding few more ingradients. It has now emerged as versatile material to meet many special requirement in engineering. The following is the list of some of the special glasses:

(a) Fibre glass
(b) Foam glass
(c) Bullet proof glass
(d) Structural glass
(e) Glass black
(f) Wired glass
(g) Ultraviolet ray glass
(h) Perforated glass.

CEMENT MORTAR USED IN CIVIL AND STRUCTURAL CONSTRUCTION BASICS AND TUTORIALS

CEMENT MORTAR USED IN CIVIL AND STRUCTURAL CONSTRUCTION BASIC INFORMATION
What Are Cement Mortar? What Are The Applications Of Cement Mortar?


For preparing mortar, first a mixture of cement and sand is made thoroughly mixing them in dry condition. Water is gradually added and mixed with shovels. The cement to sand proportion recommended for various works is as shown is Table 2.1

Table 2.1 Cement To Sand Proportion 

Curing: Cement gains the strength gradually with hydration. Hence it is necessary to see that mortar is wet till hydration has taken place. The process to ensure sufficient moisture for hydration after laying mortar/concrete is called curing. 

Curing is ensured by spraying water. Curing normally starts 6–24 hours after mortar is used. It may be noted that in the initial period water requirement is more for hydration and gradually it reduces. Curing is recommended for 28 days.

Properties of Cement Mortar: The following are the important properties of cement mortar:

1. When water is added to the dry mixture of cement and sand, hydration of cement starts and it binds sand particles and also the surrounding surfaces of masonry and concrete.

2. A mix richer than 1:3 is prone to shrinkage.

3. Well proportioned mortar provides impervious surface.

4. Leaner mix is not capable of closing the voids in sand and hence the plastered surface is porous.

5. The strength of mortar depends upon the proportion of cement and sand. Strengths obtained with various proportion of cement and sand is shown in Table 2.2.

Uses of Cement Mortar
Mortar is used
1. to bind masonry units like stone, bricks, cement blocks.
2. to plaster slab and walls make them impervious.
3. to give neat finishing to walls and concrete works.
4. for pointing masonry joints.
5. for preparing building blocks.
6. as a filler material in ferro cement works.
7. to fill joints and cracks in walls.
8. as a filler material in stone masonry.