| 摘要 |
A reinforcing bar has a controlled heating on its threaded end (or other engagement portion for engaging a coupler), which extends beyond the threads, and provides improved mechanical properties at the end. The heating may be a controlled heating that case hardens the threaded end, including heating of an unthreaded portion beyond the threaded portion. The heating may be done in multiple steps, for example with a heating/hardening, follow by cooling, a reheating for tempering, and a recooling. The bar end may be threaded into a coupler or splice, with the heated end extending axially beyond (outside of) the coupler. Regions of the reinforcing bar beyond the heated end may be untreated, and therefore weaker than the thermally-treated bar end. The resulting coupling or splice may therefore be able to achieve bar break (failure at a location in the bulk of the bar, away from the coupler). |
