In reinforced cement concrete (R.C.C.) construction, which steel type is commonly used for reinforcement bars and meshes? Select the most appropriate traditional material class used for rebars.

Introduction / Context:
R.C.C. relies on concrete for compressive capacity and steel reinforcement for tension and ductility. The material choice for rebar must balance strength, ductility, weldability, and economy. This question targets the common class of steel used in standard R.C.C. works.

Given Data / Assumptions:

• General buildings and infrastructure are considered.
• Bars require ribbing/deformation for bond and adequate elongation at failure.
• Availability, code compliance, and cost are key factors.

Concept / Approach:
Traditional and widely specified rebars are based on mild steel or low-alloy steels with controlled carbon content to ensure ductility and weldability. Even when high yield strength deformed (HYSD/TMT) bars are used, their base composition maintains relatively low carbon to preserve ductility, placing them closer to the mild steel category rather than high-carbon or stainless steel.

Step-by-Step Solution:

Verification / Alternative check:
Code specifications list characteristic yield strengths for mild steel and TMT/HYSD bars, emphasizing ductility and bend tests that align with low to medium carbon levels rather than high-carbon steels.

Why Other Options Are Wrong:

• Stainless steel: excellent corrosion resistance but costly; used selectively.
• High carbon steel: inadequate ductility and weldability for standard rebars.
• Wrought iron: largely historical in structural use.

Common Pitfalls:
Assuming higher carbon always means stronger and therefore better; in reinforcement, ductility and bond behavior are critical for seismic and redistribution demands.

Final Answer:
Mild steel (including deformed bars of mild steel/low-alloy grade)