Why is tension anchorage length generally longer than compression anchorage length?

Tension anchorage length of steel reinforcement in concrete depends on bond strength. When steel reinforcement is anchored to concrete and is subjected to compressive forces, the resistance is provided by the bond strength between concrete and steel and the bearing pressure at the reinforcement end.

Continue Reading »

What are the reasons of establishing minimum area of reinforcement and maximum area of reinforcement?

Beams may be designed to be larger than required for strength consideration owing to aesthetics or other reasons. As such, the corresponding steel ratio is very low and the moment capacity of pure concrete section based on the modulus of rupture is higher than its ultimate moment of resistance. As a result, reinforcement yields first and extremely wide cracks will be formed. A minimum area of reinforcement is specified to avoid the formation of wide cracks.

Continue Reading »

What are the reasons for establishing minimum distance between bars and maximum distance between bars?

In some codes, a minimum distance between bars is specified to allow for sufficient space to accommodate internal vibrators during compaction.

Continue Reading »

What is the difference in application between open stirrups and closed stirrups in concrete beams?

Open stirrups are provided principally to resist shear forces in concrete beams and they are applied in locations in which the effect of torsion is insignificant.

Continue Reading »

What is the mechanism of protection by hot dip galvanizing?

Hot dip galvanizing protects steel/iron from corrosion by:

(i) It forms a metallic zinc and zinc-iron alloy coating on top of steel surface. This zinc coating reacts with moisture in atmosphere to from zinc salts which act as an insulating layer for steel/iron.

Continue Reading »

Filed under Steelworks | 0 Comments