Investigation of physical and mechanical properties of engineered cementitious composite (ECC) with different fibers

It is known that the brittleness of cementitious composites is always a disadvantage and a problem. In order to eliminate and minimize this fragility, fiber is added to cementitious composites. In general, the production and use of high-strength concrete has become widespread in recent years. One of the high strength concretes is engineered cementitious composites (ECC). In this thesis, ECCs with different fibers are designed. Basalt, glass, steel, Polypropylene (PP) and Poly vinyl Alcohol (PVA) were used as fibers in the production of composites. ECC samples were produced by adding fibers in certain amounts at 0%, 2%, 3% and 4% volumetric ratios into the mixed mortars. The workability of the produced samples was determined by the collapse and spreading table test while they were fresh. Tests for determining water absorption, void ratio, capillarity, ultrasound, pressure, bending, fracture toughness and crack width from hardened concrete tests were carried out on 28-day-old samples subjected to a standard curing pool. According to the results obtained, it was observed that as the amount of fiber increased, the processability decreased, and the water absorption and void ratios increased. In the ultrasound test, steel fiber added mortars with the highest pass rate were observed, while glass fiber added mortars had the lowest values. It was observed that the compressive strength decreased as the fiber content increased. However, the opposite was observed in steel and PVA fiber reinforced mortars. Polypropylene fiber reinforced mortars are the best performing mortars in the bending test. As the fiber content increased, both the flexural strength and the deformation of the samples increased. It has been observed that the steel and glass fiber reinforced mortars do not perform efficiently in deformation in bending strength, and they break with less deformation. When the results obtained were examined, it was seen that the closest mortars compared to Poly Vinyl Alcohol (PVA) fiber added mortars were polypropylene fiber added mortars.