UNIT 1

Introduction to Civil Engineering

1.1   Various Branches and Role of civil engineer in various construction activities

• Civil engineering is the work of designing and building infrastructure.

• It usually means large structures, like bridges, dams, buildings, and tunnels. It also constructed complex networks such as water, irrigation, and sewerage networks.
• Civil Engineering gives the named as it is since it has the part of Science which deals with the comfort things essential for civilians with respect to its basic needs of shelter, transportation, workplace, and others.

• Civil infrastructure systems contain the design, analysis, and management of infrastructure subsidiary human activities, between, for example, electric power, oil and gas, water and wastewater, communications, transportation, and the collections of buildings that make up urban and rural communities.
• These networks bring essential services, provide shelter, and support social interactions and economic development.

Advantages:

• Civil engineers have become central figures in public development.
• Buildings and roads are providing by the basis of city infrastructure.
• Engineers not only provide them but used by their skills to optimize the performance and competence of community systems.
• Civil engineers take the work such as engineering work specific to building and improving community infrastructures.
• They plan, design, and monitor innovative building construction and improvements, rail and roadway projects, bridges, irrigation and sewer systems, dams, and other physical structures.

Disadvantages:

• In the initial part of the career, it will take to work very hard on both field and off-field.
• There is have a ration of cost & risk involved with the job.
• It is not a tie & get-up job, working day in and available in a well-furnished office.

Basics of Engineering and Civil Engineering:

• Engineering is the scientific discipline and profession elementary on scientific theories, mathematical methods, and empirical indication to design, create, and investigate technological solutions conscious of safety, human factors, physical laws, regulations, practicality, and cost.

Engineering Principles

• The engineering method (also called as engineering design) is an efficient method used to influence the specific solution to a problem.
• There are six steps (or phases): idea, concept, planning, design, development, and launch from problem definition to anticipated result.
• Civil engineers can make sure the design, construct, supervise, operate, and conserve large construction projects and systems, including roads, buildings, airports, tunnels, dams, bridges, and schemes for water supply and sewage treatment.
• Various civil engineers work in design, construction, research, and education.
• Civil Engineers are liable for the quality of creating, improving, and protecting our immediate environment.
• They plan and oversee construction and reconstruction, as well as the maintenance of roads, bridges, tunnels, railways, dams, harbors, power plants, and airports.

Broad disciplines of Civil Engineering:

1)      Structural Engineering:

• This correction of the examination and design of concrete and steel structures, such as multi-story buildings, bridges, towers, etc.
• It deals also with the knowledge of the durability and resistibility of such buildings for live loads, wind, and earthquakes.
• The study comprises also the study of the effects of building materials permitting international specifications.

2)      Water Resources and Hydraulics Engineering:

• This field refuges the basic ideas of water science and its related theorems and applications.
• This comprises the methods of transporting water from sources to distribution sites finished channels and pipelines, water sources and storage systems, types of dams, and design methods.
• It comprises the adjustment of seawater movements and shore protection.

3)      Geotechnical Engineering

• This field is apprehensive with the study of the soil properties of the construction site and its bearing capacity.
• Geotechnical engineering is concerned also with suitable solutions for any problem in the soil as well as the choice of the best and secured methods of design and construction of the foundation of engineering structures.

4)      Environmental Engineering

• This field is concerned with the study of the essential methods and techniques of environment protection as well as the availability of basic life elements such as water and air with a detailed level of quality to protect mankind's health and environment.
• This comprises the design and construction of water distribution networks, wastewater and stormwater collection systems, water treatment plants, and wastewater treatment for recovery in industrial and agricultural fields.
• Environmental engineering contains also the study of the different techniques of controlling air, water, and soil pollution as well as the suitable disposal or reprocess of solid and hazardous wastes.

5)      Transportation Engineering

• This self-control involves the present and future wide-ranging planning of the requirements of transportation systems, as well as the specifications of these systems such as those of roads, airports, parking lots, etc. and the management of traffic volumes with the essential design of the traffic signals and public transportation.

6)      Construction Engineering and Management

• The civil engineer is concerned with the management of engineering projects including planning and control of cost, time, and quality.
• This field is a multi-discipline area, which demands knowledge nearby business, economy, computer applications, constructability, construction equipment and methods, choice and risk analysis, engineering management, law, safety, and productivity.

Importance of Civil Engineering:

• Civil engineers play an extremely significant role in society.
• They are liable for maintaining the overall safety of society in a number of ways including rural engineering.
• Constructing highways and buildings to bridges and tunnels, the responsibilities of civil engineers are several.
• Make a lifestyle suitable and easier.
• Make the greatest land-use capacity and resources maximum.
• Confirmed the best living standard of the common man in town.
• Civil engineers develop and improve the services and amenities we use every day: from supplying energy and clean water to homes, to processing and recycling waste, to finding solutions to problems like pollution.
• Civil engineers design and shape bridges, roads, railways, and tunnels.

Possible scopes for a career:

• A career after civil engineering is highly rewarding. Some jobs contain supervision, construction, design, and training of private as well as public projects, such as dams, highways, canals, water sewages, and bridges.
• The talent demands excellent skills for both the administration and supervision of projects.
• In civil engineering, many branches are there such as structural engineering, environmental engineering, water resources engineering, construction project management, geotechnical engineering, transportation engineering. Every branch has good scope but it depends from place to place and capability.
• Any basic engineering field is good for your career at all times. Precisely, civil engineering also the advantage of getting a government job in almost every sector. 
• Civil Engineering is a professional engineering discipline and the oldest which deals with the constructed environment.
• Civil engineering is a branch of engineering which contracts with people, the civilization of a country, their needs, and basic facilities.
• So as long as there are humans and as long as we have a natural phenomenon like earthquakes and cyclones civil engineers will be required.
• Civil engineering takes place in the public sector from municipal through to national governments, and in the private sector from separate homeowners through to international companies.

1.2   Basic engineering properties and uses of materials

1)      Stones:

• Stones form one of the most important building materials in civil engineering.
• Stones are resulting from rocks, which form the earth's crust and have no definite shape or chemical mixture but are mixtures of two or more minerals.
• The mineral is a substance that is formed by the natural inorganic process and owns a certain chemical combination and molecular structure.
• They are strong, durable, and ancestry in appearance.
• Many types of stones are available such as basalt, marble, limestone, sandstone, quartzite, travertine, slate, gneiss, laterite, and granite used as construction materials. 

2)      Bricks:

• Bricks are made by determining a plastic mass of clay and water, which is before hardened by drying and firing.
• Until moderately recent times the clay was dug, the bricks were made and the kilns set or haggard by manual labor with help from animal power.
• Class A engineering bricks are the strongest, but Class B is the more commonly used.
• Interior walls made of bricks help adjust the building's temperature, as they supply heat and cool air.
• Also, comfort, a building made of bricks has some financial advantages.
• Houses made completely out of brickwork cost less in the long run, because they essential less energy for heating.

3)      Mortar:

• Mortar is a material used in masonry construction to fill the gaps among the bricks and blocks used in construction.
• Mortar is a mixture of sand, a binder such as cement or lime, and water and is practical as a paste which then sets hard.
• Mortar is the bonding material between bricks, concrete block, stone, and many extra masonry materials. It is made from Portland cement, lime, sand, and water in variable ratios.
• Each of the standard mortar mixes—Types N, M, S, and O—has different performance characteristics for dissimilar building applications.

4)      Plain Reinforced:

• Plain concrete is also known as mass concrete is when a structural member is cast deprived of the use of steel reinforcement, characteristically a wall foundation (trench).
• Composite Materials - Reinforced Concrete. Concrete is made since small stones and gravel called aggregate, sharp sand, cement, and water.
• The small stone and gravel (aggregate) is the reinforcement and the cement is the matrix that binds it together
• Plain concrete does not easily endure tensile and shear stresses caused by wind, earthquakes, vibrations, and other forces and is then unsuitable in most structural applications.
• In reinforced concrete, the tensile strength of steel and the compressive strength of concrete work composed the member to sustain these stresses over substantial spans.

5)      Prestressed concrete: 

• Prestressed concrete is concrete that internal stresses introduced to counter, to the degree desired, the tensile stresses that will be imposed in service.
• The stress is typically imposed by tendons of individual hard-drawn wires, cables of hard-drawn wires, or bars of high strength alloy steel.
• It is now usually used for floor beams, piles, and railways sleepers, as well as structures such as bridges, water tanks, roofs, and runways.
• Generally, prestressed concrete is not essential for columns and walls, however, it can be used frugally for tall columns and high retaining walls with high bending stresses.
• The principle behind prestressed concrete is that compressive stresses induced by high-strength steel tendons in a concrete member before loads are applied will stability the tensile stresses imposed in the member through service.

6)      Construction Chemicals:

• Construction chemicals consume various products, ranging from admixtures to flooring chemicals, sealants, grouts, waterproofing chemicals, and chemicals for repair and maintenance of structures.
• Polymers are the most important group of raw materials and they are predominant in every construction chemical formulation.

1)     Cement production – Combustion agents

2)     Concrete – a chemical admixture

3)     Corrosion Inhibitor –accelerator

4)     Coating – Structural applications

5)     Paint - Aesthetics

6)     Repair and Rehabilitation- Retrofit

7)     Chloride extraction: to control

8)     Corrosion Inhibitor: Migrating – High

7)      Structural Steel:

• Structural steel varies from concrete in its credited compressive strength as well as tensile strength.
• Strength - Having high strength, stiffness, toughness, and ductile properties, structural steel is one of the most commonly used materials in commercial and industrial building construction.

Properties of Structural Steel:

1)     Density.

2)     Elastic Modulus.

3)     Poisson's Ratio.

4)     Tensile Strength.

5)     Yield Strength.

6)     Melting Point.

7)     Specific Heat.

8)     Hardness.

8)      High Tensile Steel:

• High-tensile steels are low-carbon, or steels at the lower end of the medium-carbon range, consume additional alloying ingredients in instruction to increase their strength, wear properties, or specifically tensile strength.
• These alloying ingredients contain chromium, molybdenum, silicon, manganese, nickel, and vanadium.
• So, the key difference between mild steel and high tensile steel is that high tensile steel takes a high strength than mild steel.
• High tensile steel like HT690 has an actual high yield point and demonstrates a reduced plastic ductility and brittle fracture behavior as associated with mild steel.

9)      Carbon Composites:

• Carbon fiber is used mainly in the strengthening and reinforcement of concrete, steel, timber, and masonry.
• The properties of carbon fiber, such as high strength, rigidness, and tensile strength brand it a popular material in civil engineering.
• Composite materials are shaped by combining two or more materials that have fairly different properties.
• The different materials work together to give the composite single properties, but inside the composite, you can easily tell the different materials apart – they do not dissolve or blend into each other.
• Carbon-carbon composites contain carbon fibers in a graphite matrix. The carbon fibers used high modulus, and exhibition relatively high tensile strength (Mallick, 2007). 
• Carbon fiber is factory-made by graphitization of precursors such as a textile or pitch.

10)   Plastics in Construction:

• Many construction companies are consuming plastic materials.
• The components used include the whole thing from plastic screws and hinges to bigger plastic parts that are used in decoration, electric wiring, flooring, wall coverings, waterproofing, and so on.
• Plastic can too be easily removed and some plastics can be recycled.
• The disadvantages of plastic are high personified energy content and a low modulus of elasticity, meaning that it is usually unsuitable for load-bearing applications.
• Examples of plastics used in the building are:

1)     Acrylic.

2)     Composites.

3)     Expanded Polystyrene.

4)     Polycarbonate.

5)     Polyethylene.

6)     Polypropylene.

7)     Polyvinyl Chloride.

11)  3D printing:

• Like most, their concrete 3D printer uses material extrusion knowledge.
• They have industrialized their own material mix, which is an extrudable concrete consisting of cement, sand, geopolymers, and fibers.
• There are a variety of 3D printing methods used at construction gage, with the main one's actuality extrusion (concrete/cement, wax, foam, polymers), powder bonding (polymer bond, reactive bond, sintering), and additive welding.
• 3D printing at a construction scale will take a wide variety of applications inside the private, commercial, industrial, and public sectors.
• Potential advantages of these technologies comprise faster construction, lower labor costs, increased complexity and/or the accuracy, greater integration of function, and less waste shaped.

12) Recycling of Construction & Demolition wastes:

• Construction and demolition waste is generated when any construction/demolition activity takings place, such as building roads, bridges, flyovers, subway, remodelling, etc.
• It consists typically of inert and non-biodegradable material such as concrete, plaster, metal, wood, plastics, etc.
• A part of this waste originates from the municipal stream.
• All attempts made to stick to the following measures.
• All construction/demolition waste should be stored inside the site itself.
• A proper screen should be provided so that the waste does not get scattered and does not develop an eyesore.
• Attempts should be made to retain the waste segregated into different heaps as far as possible so that their additional gradation and reuse is facilitated.
• Material, which can be reused at the same site for the purpose of construction, leveling, making road/pavement, etc. kept in separate loads from those, which are to be sold or landfilled.
• The local body or a private company may position to provide an appropriate number of skip containers/trolleys on rental which may be parked at the site and removed with skip lifters or tractors
• Whenever a new streamlined system is familiarized in a municipality, the local body may consider by means of its old vehicles, especially, tractors and trailers or old lorries or tippers for this purpose.
• For large projects linking the construction of bridges, flyovers, subways, etc., special provisions made for the storage of waste material.
• Depending on the storage capacity, the movement of the waste has planned accordingly.
• Otherwise, it results in job constraints as well as traffic bottlenecks.