constructional vs structural

constructional

adj
  • Of, pertaining to, or obtained by construction. 

structural

adj
  • Of, relating to, or having structure. 

  • That is lasting. economics 

  • Involving the mechanics of construction. 

noun
  • Structural steel, used in construction. 

How often have the words constructional and structural occurred in a corpus of books? (source: Google Ngram Viewer )