Effect of Polypropylene Fibers versus Macrobarchip on the Characteristics of Plastic Concrete

Document Type : Original Article

Authors

1 Department of Civil Engineering, Faculty of Engineering, University of Guilan, Rasht, Iran.

2 Department of Civil Engineering, Faculty of Engineering, University of Guilan, Rasht, Iran

Abstract

Plastic concrete is widely used in the construction of cut-off walls of earth dams. The mechanical properties and behavior of the materials used in the construction of such walls are of particular importance due to the loads on the foundation and the waterproofness of wall. Fracture energy is considered to be the most important influencing factor in the description of fracture behavior, which actually describes the cracking mechanism of concrete. This research aims to study the effect of adding 12 mm polypropylene fibers and 30 mm macrobarchip fibers to reinforce plastic concrete of cut-off walls. The studied properties include: concrete mix slump determination test, concrete ultrasonic test, modulus of elasticity, stress-strain curve, concrete permeability, scanning electron microscope (SEM) and compressive strength at the age of 28 days. The results obtained from fresh concrete mixtures show that the specific weight and slump are reduced for both types of fibers. The highest decrease in PP fibers was 52.27%. The results of the ultrasonic test indicate a 9.47% decrease in wave speed for PP fibers and 14.17% for macro fibers. Based on the 28 day compressive strength results, the addition of fibers have reduced the compressive strength as much as 27.20% for PP fibers and 23.32% for macro fibers. According to the results of the modulus of elasticity, adding fibers reduces this characteristic of plastic concrete. such that the highest value for PP fibers is 16.98% and 24.70% for macro fibers.

Keywords


 
 
 
 
CAPTCHA Image