Question

Question 3 1) write three types of concrete and steel-grades 2) write three advantages for concrete 3) write three advantages for steel 4) Draw stress-strain diagram for concrete 5) Draw stress-strain diagram for steel

Answer 1

Part 1:- Three types of concrete grades are :-

• M 20 - The characteristic compressive strength of M 20 grade concrete at 28 days is 20 N/mm^2. This grade of concrete is used for domestic purposes.

• M25 - The characteristic compressive strength of M 25 grade concrete at 28 days is 25 N/mm^2. This grade of concrete is used for domestic and commercial purposes.

•M 30 - The characteristic compressive strength of M 30 grade concrete at 28 days is 30 N/mm^2. This grade of concrete is used for commercial purposes.

The three types of steel grades are:- Fe represents the ferrous steel or iron steel.

• Fe 250 - The yield strength of this steel is 250 MPa. It is a mild steel bars ( or plain bars) having very high ductility.

• Fe 415 - The yield strength of this steel is 415 MPa.

• Fe 500 - The yield strength of this steel is 500 MPa

The steel grade Fe 415 and Fe 500 are the high yield strength deformed bars (HYSD bars). These bars do not have definite yield point as can be clearly observed in mild steel bars. Fe 415 and Fe 500 HYSD bars are stronger than Fe 250 mild steel bars.

Part 2:- Three advantages for concrete are as follows :-

• The ingredients of concrete are easily available. Also, concrete hardens with age and the process of hardening continues for a long time.

• Handling and Moulding of concrete to any shape is easy. Also, Concrete forms a hard surface and is capable of resisting abrasion.

• Transportation of concrete from the place of mixing to the place of casting is easy before its initial set take place.

Part 3:- Three advantages for steel are :-

• Steel is stronger in tension and hence, it increases the ductility of the structure when steel is used as a reinforcement in concrete structures.

• Steel has the high strength per unit mass which means that the requirement of steel sections will be small and lightweighted no matter how large is the overall structure.

• Steel is very durable, ductile, malleable and tough. It can also withstand the external pressures and loads due to dead, live, wind, earthquake and snow.

Part 4 and Part 5:- The stress-strain diagram for concrete and stress-strain diagram for steel are shown in below image.

IPAGE No Part 4: Stress-strain diagram for concrete:- From code IS 456:2000 Stress Idealised for cruise вск 2228 Characteristic 0.67 fck 4 curve for concrete 0.67 fck Partial FOS design curve (Tm) 0.0035 ro 0.002 Strain Parabolic. Part 5:- Stress - Strain diagram for steel :- Stress (ultimate) fu fy (Yield Stress E TYTUT 1 B linear t - Curve Strain a b f A Proportional Limit B = Elastic linit с Upper yield point D = Lower yield point DE = Plastic region EF = Strain hardening region F = Ultimate strength FG = Necking region G - Fracture point. Tearters Sijorture