Reinforcement

Reinforcement material required for reinforcing concrete should possess the following characteristics; high tensile strength, achieves tensile strength without undue strain, abilities to be bent to shapes, have surfaces capable of having adequate bond with concrete paste, economical as well as have sufficient coefficient of thermal expansion.
Chudley and Greeno (2005) stated that “Materials that meet the above requirement is steel in form of bars and is supplied in two basic types; mild steel and high yield steel”. They also emphasized on the British standard specifications as BS4449 and strength of the bars as 250N/mm2 and 460N/mm2 for mild steel and high yield respectively.

In the design of a structure, the designer show ensure the most economical way of specifying reinforcement as well as reduce the use of multi diameter reinforcement. “A good design will limit the ranges of diameters used together with the type of steel chosen to achieve an economic structure and to ease the site processes of handling, storage buying and confusion that can arise when the contractor is faced with a variety of similar materials” (Chudley & Greeno, 2005).
Another form of reinforcement used in construction is fabric mesh reinforcement which is covered by BS4483. Chudley and Greeno (2005), highlighted 4 basic types of fabric mesh and there uses:

1. Type ‘A’ for square mesh (floor slab)

2. Type ‘B’ for rectangular structural (slab)

3. Type ‘C’ for long mesh (road and pavement)

4. Type ‘D’ a small wrapping mesh (binding concrete fireproofing)

Reinforcement is purchased in tones and is storage in a dry area around the site away from moisture. Rust is a major defect in reinforcement which can greatly reduce the strength of the concrete. A high level of wastage can have great effect on the cost of concrete as well as the total construction cost.