1 Concrete Technology Introduction

Concrete Technology

Design Principles of Concrete Structures

• • Concrete Structures (Part-I) by Zahid Ahmad Siddiqi
    
    .References
    
    • Reinforced Concrete (6th Edition) by Edward G. Nawy
      
    • Design of Concrete Structures (14th Edition)
      

      by Arthur H. Nilson, David Darwin & Charles W. Dolan
      

    • Building Code Requirements for Structural Concrete
      

(ACI 318-19)

Concrete

Concrete

Concrete is a mixture of cement, fine and coarse aggregate.

Concrete mainly consists of a binding material and filler material.

If filler material size is < 4.75 mm it is fine aggregate and > 4.75mm is coarse aggregate. (ASTM Sieve #4)

Concrete

Plain Cement Concrete (PCC)

Mixture of cement , sand and coarse aggregate without any reinforcement is known as PCC.

PCC is strong in compression and week in tension. Its tensile strength is so small that it can be neglected in design.

Reinforced Cement Concrete (RCC)

Mixture of cement , sand and coarse aggregate with

reinforcement is known as RCC. (Tensile strength is improved)

Concrete

Common Mix Proportion

Cement : Sand : Crush

1 :1.5 :31 :2 :4
Water Cement Ratio (W/C)1 :4 :8W/C = 0.5 – 0.6

For a mix proportion of 1:2:4 and W/C = 0.5, if cement is 50 kg

Sand= 2 x 50 = 100 KgCrush Water= 4 x 50 = 200 Kg
= 50 x 0.5 = 25 KgBatching By WeightBatching by Weight



Classification of Grades of Concrete

Batching by Volume

Mechanism of Load Transfer

Function of structure is to transfer all the loads safely to ground.
A particular structural
Roof Slab
Load
Roof Surface
member transfers load to other structural member.
Beams
Column
Foundation
Sub Soil

Mechanism of Load Transfer

Mechanism of Load Transfer

Merits of Concrete Construction

Good Control over cross sectional dimensions and Shape One of the major advantage of concrete structures is the full control over the dimensions and structural shape. Any size and shape can be obtained by preparing the formwork accordingly.

1. Availability of Materials
   

   All the constituent materials are earthen materials (cement, sand, crush) and easily available in abundance.
   

2. Economic Structures
   

   All the materials are easily available so structures are economical.
   

3. Good Insulation
   

   Concrete is a good insulator of Noise & heat and does not allow them to transmit completely.
   

   Merits of Concrete Construction (contd…)
   

4. Good Binding Between Steel and Concrete
   

   there is a very good development of bond between steel and concrete.
   

5. Stable Structure
   

   Concrete is strong in compression but week in tension and steel as strong in tension so their combination give a strong stable structure.