Specific material used for construction (8)
I believe the answer is:
concrete
'specific' is the definition.
(thesaurus)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for concrete that I've seen before include "It's composed of sand, cement and water" , "Definite; building material" , "Strong, hard, building material" , "factual type of evidence?" , "Actual - stuff made with cement" .)