Question

For 2nd class building rain water pipes shall be of ______________ finished painted.

(a) Cast iron

(b) Bog iron

(c) Brown ore

(d) Pyrite

This question was posed to me in semester exam.

I'd like to ask this question from General Specifications topic in chapter Specifications, Estimation of Quantities of Materials and Transport of Civil Engineering Drawing

Answer 1

Right choice is (a) Cast iron

The best explanation: Cast iron is a group of iron-carbon alloys with a carbon content greater than 2%.[1] Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its colour when fractured: white cast iron has carbide impurities which allow cracks to pass straight through, grey cast iron has graphite flakes which deflect a passing crack and initiate countless new cracks as the material breaks, and ductile cast iron has spherical graphite “nodules” which stop the crack from further progressing.