Day: June 9, 2011

A rapid-hardening mix promoted for fast formwork removal, Promptis is the charter offering in a family of branded ready mixed products Cemex, S.A.B. de C.V., envisions for its worldwide markets. Dosed with proprietary admixtures, the new material reaches early compressive strength in as fast as four hours, compared with an average of 18 hours in conventional concrete. Despite its rapid-hardening properties, Promptis is formulated to retain workability for over 90 minutes, thus allowing it to be easily handled without the risk of sudden hardening—even under extremely hot weather exposure. Mix strengths develop progressively with age, yielding a highly durable material that also exhibits a good resistance to shrinkage cracking.

One in nine bridges and overpasses is rated in poor enough condition that they could become dangerous or be closed without near-term repair, according to a Transportation for America report “The Fix We’re In For: The State of the Nation’s Bridges.” Nearly 70,000 crossings nationwide are rated “structurally deficient” and need substantial repair or replacement, authors contend, while the Federal Highway Administration estimates that the backlog of potentially dangerous bridges would cost $70.9 billion to clear—versus a current federal outlay just over $5 billion per year.