Relaxation of concrete and its relation to creep under uniaxial cyclic compression at various frequencies Available to Purchase

Following an earlier creep investigation, relaxation of five-day cyclic compressive stress under constant cyclic strain is reported for frequencies ranging from 1 cycle per day to 1·2 Hz. As with creep, relaxation has to be defined carefully because of the shape of the stress–strain curve. On the other hand, in contrast with creep, there is no increase in relaxation from a frequency of 30 cycles per hour to 1·2 Hz. Relaxation under a cyclic strain can be related to creep but the established methods of estimating stress from strain require modification. Using a modified Effective Modulus approach, the full stress cycle after relaxation can be predicted from static creep.