Experimental study on mechanical behavior of serving prestressed concrete poles

In order to assess accurately safety performance of prestressed concrete poles servicing 30 years, bending loading tests are carried out on 3 samples extracted randomly, these ones are studied on the mechanical behavior and failure mechanism, failure modes are revealed, and important experimental data including cracking load, the ultimate load of normal use, the ultimate load of carrying capacity is obtained. Furthermore, based on measured test data, the curves of load-crack width and moment-deflection are made among the whole force process. The results show that failure modes of specimens are similar to one of "rare-reinforced beams". Moreover, based on design method of serviceability limit state, the average security surplus coefficient is 1.2 before collapse damage.