BUILDING AND CONSTRUCTION TECHNOLOGY

9. Parts of a Building Plan

The Construction plan defines the construction materials required to build the respective building.The construction plan consists of 1. Ground Plan 2. Sectional Elevation 3. Front Elevation 4. Side Elevation 5. Door,Window details 6. Floor Plan 7. Foundation Setup

9.1 Ground Plan

The Parts below roof level of a building is called the ground plan. the marking of the floor is for the Door and Windows . By this the width of the wall and the position of the room and internal measurements of buildings and doors and windows and curves , Door Steps are shown.

Generally when drawing the ground plan , Metric Value are used on a 1:1000 scale. Anyhow in some special occasions the scale may change.

10. Cement

Usually many types of cements are produced. They are used in various instances for which they were developed. For General construction works Ordinary Portland Cement is used.

10.1 History of Cement

“Cement” originated from the meaning of mixing small miniature particles into water and producing stronger bonding. It was named by Joseph Aspdin, a British Engineer.

The function of a Hydrated Cement is alike the process stated. Cement was first used in Egypt and thereafter used in Greek and Babylonia. Romans used Volcanic Dust with Limestone to produce cement.

As of 1871, Cement had been commercially produced in United States of America.Today most of the cement produced is Ordinary Portland Cement.

10.2 Types of Cement

Generally many types of cement are available in market. They are produced for a certain purposes. Mostly Produced Cement Types are

1.Ordinary Portland Cement 2.Rapid Hardening Cement 3.Quick Setting Cement 4.Water Proof Cement 5.High Alumina Cement 6.Sulphate Resistance Cement 7.Masonry Cement 8.White Cement 9.Coloring Cement 10.Low Head Portland Cement 11.Super Sulphate Cement

10.2.1 Ordinary Portland Cement (OPC) - SLS 107

High Market Availability
Low Cost
Usable on ordinary situation for all works Eg:- Concrete, Precast

10.2.2 Rapid Hardening Cement (RHC)

Produced as like as OPC but the mixture hardens quicker than OPC due to a catalyst.
OPC needs 28 days to strengthen
RHC needs 4 days to strengthen
Cement mixture is produced by adding 2% of CaCl
The Settling time of this Cement remains same as OPC. This can be used for quick construction works , weight loading works.
As quickly hardens , the shuttering work can be removed quickly.

10.2.3 Quick Setting Cement

The Gypsum is not added to this type of Cement Milling.
Small amount of Aluminum Sulphate - 2% to 4% is added to the mixture while milling.
Because of these reasons the cement quickly settles down.
Time Taken to Settle Down - 5 Minutes to 10 Minutes
This type of Cement is used in locations where more moist is found and helps to quickly settles down.

10.2.4 Water Proof Cement

In Cement production 2% of Calcium and Aluminum are added to produce this exact type of cements.
This Cement is typically used in structures which are in subsequent exposure to Water/Moisture.
The Cement is used 2%-5% in Global Cement usage calculations.

10.2.5 High Alumina Cement

This cement constitutes of 35% of Calcium Oxide and 25% to 55% of Aluminum Oxide and 5% to 15% Ferric Oxide and 5% to 10% of Silica.
This cement can sustain its strength up to 1300° Celcius.
This cement is used in construction of Kilns and High Heat Furnaces.
This cement can also sustain Acidic and Basic Situations.

10.2.6 Sulphate Resistance Cement

This type of cement constitutes of
Lime 64%
Silica 24%
Alumina 4%
Ferric Oxide 4%
Unlike Portland Cement, this type of cement gains 75% of strength in 3 days and 85% in 28 days. This type of cement resists Sulphate Reactions and Protect Buildings.
This Cement is used in North America where high sulphate content is found in some soils.
Drainage and Sewage drains are plastered using this cement to prevent corrosion from chemical substances.

10.2.7 Masonry Cement

This type of cement is produced by adding more calcium to the clinker.
This can be more softer than the OPC and easier to work with and can produce more smoother surface.
This cement has high softening factor, high workability and load reduction.
As this cement produces softer surfaces , this is helpful in finishing works and reduce further costs in softening.

10.2.8 White Cement

This type of cement is produced by using the Porcelain(Chinese clay) instead of normal clay.
Used for decorative works
The whiteness of the cement has been obtained by addition of Calcium Hydroxide and Ferric Oxide.
This cement has same strength of OPC, but whiter than OPC.

10.2.9 Color Cement

This is produced by mixing various colors to OPC. (10% of Color)
Ferric Oxide
Red
Yellow
Brown
Manganese Oxide
Black
Brown
Cobalt
Blue
Chromium Oxide
Green

10.2.10 Low Heat Portland Cement

This type of cement is used in massive construction works like as Dams , Retainer Walls, Bridges.
This cement produces less heat than Ordinary Portland Cement because of this, hair cracks are prevented from forming in Buildings.

10.2.11 Super Sulphate Cement

This gives much protection against corrosion.
When using this cement, up to the curing period, the surface should be maintained wet and curved.
This cement cannot be stored in high humidity areas.

10.3 Cement Production

10.3.1 Raw Materials

Calcium Carbonate - 78%
Purification Factor - 75%
Available in Sri Lanka @
Kankesanturai
Puttalam - Single Layered
Coral Limestone (Not used as it threatens sea life forms.)
Clay - 20%
Consists of
Silica
Alumina
Iron Oxide
Available in Sri Lanka @
Murungan , Mannar
If the Iron Oxide lacks required level, Limonite is added.

10.3.2 Production

Generally cement production consist of 4 steps.

1.Identifying and gaining Raw Materials(Quarrying) 2.Preparation of Raw Materials 3.Clinkering 4.Cement Milling/Rolling

10.3.2.1 Quarrying

Limestone, Clay are obtained from various places and they are stored in separate silos.

10.3.2.2 Preparation State

Here lime is crushed into small stones and stored.
Clay is purified of vegetation wastes and chemical wastes and stored.

10.3.2.3 Clinkering

This step is important in portland cement production.
Clinkering is done is 6ft Wide, 132 feet long ,15˙ horizontally tilted continous rolling machine.
The machine’s inner chamber is heated using pressurized gas from furnace fuel or coal.
It is heated to a maximum of 1400˙ C to 1600˙ C.
Raw materials are properly mixed and feeded into the machine. These raw materials melt in high temperature and gain several changes. These changed raw materials are cooled in cooling section.
The clinker produced has the color of grey and are very hard globules.

10.3.2.4 Cement Milling

Here clinker is mxed with 3% to 5% of Gypsum (CaSO[4] . 2H[2]O) in the Ball mill
60 mm diameter iron balls grind the clinker with gypsum.
Thereafter 30 mm steel balls finely grind the crushed mixture.
The cement produced is stored in long high raised vacuum silos.
After that they are packaged in 50Kg bags or delivered in mass amounts

10.3.3 Physical Features of Cement

10.3.3.1 Finess

Small particles are the best for the tidyness of the cement. This applies British standard (BS-12(1991)) to OPC and 325Kgm^-2 Finess enables to work easily but cost more on production of it. The water absorption late is low. More finess increases chances for hair cracks

10.3.3.2 Hydration

The chemical constituents or componds react with water is called hydration of cement. Because of this reaction, cement forms a strong bonding with sand and stone. By hydration, heat is produced. This does not affect small scale works, through adversely affects in large or very large scale works. Concrete works done in cold season take advantage of heat but in hot season large scale construction works produces thermal cracks in concrete.

10.3.3.3 Soundness

No change in the volume after strengthening of cement is called soundness of cememnt

If cement contains calcium oxide or magnesium oxide in unacceptable amounts, its called the unsoundness of the cement

10.3.3.4 Setting time and Strengthening

This is connected to the hydration of cement and the start of the reaction of cement with water is the initial setting time.

OPC - 30 Mins
QSC - 5 Mins

The setting time depends on following factors

Composition of Cement
Finess of Cement
Hydration rate of Cement
Environment Temperature

10.3.3.5 Strength

The strengthening factor of cememnt is important. The strengthness of cement depnds on

Physical and Chemical features of Cement
Curing method
Water and Cement ratio

11. Lime

Lime is an ancient construction material used in Sri Lanka. This is mostly used in Anuradhapura and Polonnoruwa. The lime paste is used in Sigiriya.

These days cement has replaced the Lime in most cases but in some instances to obtain better finish of building in the inside, the Lime is used.

11.1 Raw Materials of Lime

The raw materials for lime are derieved from the following

Limestones
Seashells
Coral Reefs
Dolamite

Raw lime also contains contaminents such as MgCO[3], Al[2]O[3],SiO[2]. The standard for Lime is, SLS:552 (1982).

1 CaCO[3]         -->    CaO + CO[2]
2 CaMg(CO[3])[2]  --> CaCO[3]+ MgO + CO[2]

The quicklime is obtained by heating pure limestones, seashells to 900° C. Pouring/Spraying water on the quicklime produces Hydrated Lime Ca(OH)2 or Slake Lime.

11.1.1 Hydration of Lime

During this procedure, Calcium Oxide is exposed to water. By doing this,

Cracks form
Engorges to large space
Gains granularity of powder
Subsequent levels of heat and steam release
CaO + H2O —> Ca(OH)2

This operation is normally handled in Kilns straight after obtaining Quick Lime. The unburnt or overburnt lime must be removed before this procedure.

12. History of Building and Construction Technology

The building construction technology has existed since evolution of human civilization. It had grown throughout the times and today it had reached miserable status. In this way, the people of ancient civilizations has used excellent technologies to construct buildings. That has been proved by 1. Egytian Pyraminds 2. Mohanjadaro Harappa Buildings 3. Roman Buildings - Colosseum

In Early times human dwellings have consisted of caves. Later on humans had created various architectural achievements.

13. Materials for Construction of a Building

There are several materials required to construct a building rather than construction materials. They can be either legal documents or drafts about the building.

13.1 Classification of Construction materials

Natural	Artificial	Solid	Liquid	Binding	Protection
Lime	Cement	Cement	Water	Cement	Concrete Stone
Sand	Concrete Stone	Concrete Stone	Paint	Lime	Brick
Rubble	Brick	Brick		Sand	Cement Block
Water	Cement Block	Cement Block		Water	Bricks Hold
	Bricks Hold	Bricks Hold			Glazed
	Glazed	Glazed			Steel Rods
	Steel Rods	Steel Rods			Metal Plates
	Metal Plates	Metal Plates			Copper Pipes
	Copper Pipes	Copper Pipes			Galvanized Pipes
	Galvanized Pipes	Galvanized Pipes			PVC Pipes
	PVC Pipes	PVC Pipes			Paint
	Paint	Lime
		Sand
		Rubble

When using the above materials , general information about features of them are required. * General Physical Features * Density/Thickness * Usability * Cost * Malleability * Thermal Factors * Ignition Rate * Boiling Point * Expansion Ratio * Thermal Capacity * Heat Transfer Rate *Chemical Features * Irritation Resistance * Surface Pull Rate * Water Absorption Rate