Mechanical properties of engineered cementitious composite using polyvinyl alcohol fibers

Abstract

Engineered Cementitious Composite (ECC) is an advanced construction material that combines cement, fine aggregates, and specially designed fibers to create a highly ductile and durable building material. ECC is renowned for its exceptional tensile strain capacity, allowing it to undergo significant deformation while retaining its structural integrity. This characteristic makes ECC particularly suitable for applications where flexibility and durability are paramount, such as in earthquake-resistant structures and infrastructure repairs. This study investigates the tensile and flexural properties of ECC using Polyvinyl Alcohol Fibers (PVA) and compares these properties with those of regular mortar. Various sizes of PVA are available, and for this study, we utilized 12mm PVA fibers. The trial concrete mix design used was M30, with a watercement ratio of 0.3. The mixing process for traditional concrete and ECC is similar. Initially, the dry combination of ingredients is mixed for one to two minutes, followed by the addition of High Range Water Reducer (HRWR), and the mixture is further stirred for an additional three minutes. Finally, fibers are incorporated to achieve a stable condition for mixing. The samples used for testing consisted of 15 beams and 15 cylinders. The beam dimensions were (500 X 100 X 100) mm, while the cylinder dimensions were 100 mm in diameter and 200 mm in height. These samples were tested after 28 days of curing. The experimental findings indicate that PVA-enhanced concrete exhibits greater tensile and flexural strength when compared to conventional concrete, with results varying based on the percentage of PVA used. The split tensile strength of 1.5% PVA ECC cylinders was enhanced by approximately 46.8%. In terms of flexural strength, there was a decrease observed in 0.5% and 1% PVA fiber beams compared to ordinary concrete beams. However, the 1.5% PVA fiber beam exhibited a 43.45% improvement over the 0% fiber beam and showed a 9.4% increase compared to the 2% PVA beam. Additionally, the 1% PVA sample in the soundproof test reduced sound by up to 21.2%.