High yield steel is the preferred material for the reinforcement of concrete carriageway because of the following reasons:
(i) The principal function of steel reinforcement in concrete pavement is to control cracking. If mild steel is adopted for reinforcement, upon initiation of crack formation mild steel becomes overstressed and is
prone to yielding. High yield steel offers resistance to crack growth. The above situation is commonly encountered where there is abnormal traffic loads on concrete carriageway exceeding the design limit.
(ii) High-yield steel is less prone to deformation and bending during routine handling operation.
(iii) In the current market, steel mesh reinforcement is normally of high-yield steel type and the use of mild steel as road reinforcement requires the placing of special orders to the suppliers.
This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.