Investigating the Effect of Loading Rate on the Behavior of Plastic Concrete Samples Consisting of Different Types of Fiber: A Case Study of Nargesi Embankment Dam

One of the important issues in the construction of dams is plastic concrete cut-off walls. Careful study of the behavior of the used plastic concrete and the factors affecting it are essential concerning the failure in understanding its proper behavior that may cause irreparable damages. In line with determining the correct behavior of plastic concrete, investigating the effect of loading rate on the behavior of this concrete is considered as one of the factors affecting the stress-strain curve. In this research, in addition to studying fiber effects on the plastic concrete behavior, concrete samples were made with no fibers rather than polypropylene fibers, hooked and corrugated metal fibers with 0.19 % vol. that were under pressure load for 28 days at loading rates of 0.4, 0.6, 0.8, 1.0, 1.2 and 1.4 mm / min. The results indicated that an increase in the loading rate from 0.4 to 1.4 mm / min increased the compressive strength up to 18.8, 17.3, 11.1 and 23.2 percent, respectively; Besides, it increased the elasticity modulus of samples made of plastic concrete, with no fibers rather than polypropylene fibers, hooked and corrugated metal fibers up to 29.1, 31.8, 7.9 and 25.6 percentage. In addition, by adding fibers to plastic concrete samples, the stress-strain behavior of samples was improved by increasing the surface under the stress-strain curve and strain hardening.