Jan 11 (Reuters) - Construction chemicals maker Sika (SIKA.S) reported on Tuesday a 17.3% rise in 2021 sales, boosted by a raft of acquisitions and the upturn in the building industry after pandemic closures the year before. The Swiss company, whose products are used to reinforce and water-proof concrete, said full-year sales rose to 9.24 billion francs ($9.98 billion) from 7.88 billion francs in 2020. ($1 = 0.9262 Swiss francs) Reporting by John Revill in Zurich and Akanksha Khushi in Bengaluru Our Standards: The Thomson Reuters Trust Principles.