Civil Engineering basics are the basic parameters related to different civil engineering fields and Structures. All engineers should know these basics and especially expected from freshers. These are some very important basics.
- 25 Kn/ cum is unit weight of concrete
- 78.5 Kn/ cum is unit weight of steel
- 10 Kn/ cum unit weight of water
- 1 cement bag is 50 kgs.
- Standard size of brick is 19 cm X 9cm X 9cm
- Piles Transfer the Loads by friction or by end bearing.
- Slope of Stair shall not exceed 40 degrees.
- Preferably limit the number of steps to 12 per flight
- 1 cum Volume has 500 no of bricks.
These basic civil engineering concepts should be memorized and are useful in day to day work of civil engineer.
Following are list of Topics related to Concrete structure are covered
- Construction Materials
- Basic Terminology
- Basic understanding of structures
- Various Loads on the structure
The Basic construction materials are
Cement :- Cement is basically obtained by grinding the stones containing lime and clay. Cement is the binder which helps in the bonding of cement, sand along with water.
Some of the very important types of cement are
- Low Heat cement used generally in construction of dams.
- Sulphate resisting cement used in corrosive type environment. Ex. Sewage contact surfaces
- Rapid hardening cement
- Quick setting cement
Aggregates : – Aggregates are generally of two Types 1) Fine Aggregate and 2) Coarse Aggregate
Fine aggregate is the one that passes through 4.75 mm sieve and retained on 0.075 mm sieve
Coarse aggregate is the one that retains on 4.75 mm sieve.
Example of Fine aggregate – Sand
Example of Coarse aggregate – Gravel
Concrete :- Concrete is obtained by mixing cement, aggregate and water as per desired mix. Here water to cement ratio plays important role. Strength of concrete is inversely proportional to water cement ratio.
Concrete is represented by nomenclature as M-25.
M is Mix and 25 means compression strength at the end of 28 days considering concrete cubes of 15 cm cube.
Concrete has Two setting types
- Initial Setting time – 30 min
- Final Setting time – 10 hrs
The test for setting time is done using Vicats apparatus.
Concrete setting time can be reduced or increased depending on climatic conditions by using admixtures.
Admixture for increasing the setting time is called retarder and for reducing the setting time is called accelerator.
Note : The mixture of cement, water and sand is called mortar and is generally used for plastering works.Cement Mortar
Civil Engineering Basics related to Terminology
- Sub-structure :- Part of structure which is below the ground level is called substructure
- Super-structure :- Part of structure which is above ground level is super structure.
- Elevation – It’s the view which we can see when we stand right in front of the structure on any of the sides.
- Plastering – A cement, sand and water mix applied on brick wall for smooth surface for painting.
- Plinth level – The level on which the actual structure stands on.
- Riser – The vertical height of single step.
- Tread – The horizontal portion where we put our foot on which going on steps.
- Going – The inclined portion of stairs.
- Footing – The bottom most part of structure. These are categorized as Isolated footing, combined footing, Raft etc.
- Columns – The vertical members of structure .
- Clear cover – It’s the clear distance maintained from concrete face up to face of the reinforcement steel.
- Effective depth – It is the distance from top of the concrete face upto the CG of reinforcement.
- Singly reinforced section – A section of concrete member with reinforcement at only on tension face.
- Doubly reinforced section – A section of concrete member with reinforcement on both tension and compression side.
- Stirrups –Steel bent in closed shape of either Rectangular of circular shape. These are generally to hold column bars in position and also effective in shear carrying capacity.
- Cantilever beam – A beam with fixed support on one side and the other end is free.
- Propped cantilever – A beam with fixed support on one side and other end is with pinned support.
- Pedestal – When Length of the member is less than 3 times in width then its called pedestal.
- One way slab – When ratio of length to width is more than 2 its one way slab
- Two way slab – When ration of length to width is less than or equal to 2 , its two way slab.
- Slender column – when length to width ratio of column is more than 12 , then its slender column
- Plain cement concrete (PCC) – The cement concrete mix provided on the ground level over which foundations, beams are constructed. This is simply a levelling surface.
- Pile foundation – The foundation system with Piles i.e cylinder shaped reinforced concrete member.
- Frog – A small Depression on top of brick. This is for proper bonding with other bricks.
- Scaffolding – A temporary structure, when work needs to be carried out at higher elevations.
- Retaining wall – A wall constructed to retain earth.
MYLEARNINGS IN BASIC UNDERSTANDING OF STRUCTURE
Any structure typically consists of following
- Main Walls and partition walls.
- Flooring i.e tiles
- Finishes – Plastering and Painting
- Boundary wall
Basic loads on structure
- Self weight of structure i.e slabs, beams, columns, walls etc.,
- Live Loads due to furniture, equipment, machinery etc.
- Wind Loads
- Seismic Loads / Earthquake Loads
- Snow Loads
- Hurricane Loads at some locations
Various foundation types adopted are
- Open foundation i.e Isolated footing/ combined footing/ Raft
- Pile Foundation
List of Major American codes
- ACI 318 – Specifications for Structural concrete for buildings
- ASCE 7-05 – Specification for Loads on buildings
- AASHTO – Specifications for bridges
- AISC 303 – For structure steel building
List of Major Indian Codes
- Code for Reinforced concrete – IS 456
- Specifications for steel construction – IS 800
- Wind Loads on building – IS 875
- For Seismic Specifications – IS 1893
- For water retaining structures – IS 3370