Open AccessImproving Geopolymer Characteristics with Addition of Poly-Vinyl Alcohol (PVA) Fibers
Author(s) -
Januarti Jaya Ekaputri,
Chikako Fujiyama,
Nobuhiro Chijiwa,
Tu Dac Ho,
Hùng Thanh Nguyễn
Publication year - 2021
Publication title -
dimensi teknik sipil/civil engineering dimension
Language(s) - English
Resource type - Journals
eISSN - 1979-570X
pISSN - 1410-9530
DOI - 10.9744/ced.23.1.28-34
Subject(s) - materials science , geopolymer , sodium silicate , ultimate tensile strength , compressive strength , sodium hydroxide , composite material , vinyl alcohol , polyvinyl alcohol , fiber , fly ash , alkali metal , polymer , chemical engineering , chemistry , organic chemistry , engineering
This paper presents the benefits of PVA fibers in improving the mechanical properties of class F fly-ash-based geopolymer concrete. The activator used in the geopolymer was 8M sodium hydroxide (NaOH) and sodium silicate (Na2SiO3), with a mass ratio of Na2SiO3 to NaOH varied from 1.5 to 2.5. Cylindrical specimens with a diameter of 100 mm and a height of 200 mm were prepared for mechanical strength tests. The PVA fibers in the geopolymers were fixed at 0.4%, 0.6%, and 0.8% by total volume. Some mechanical tests were carried out, including compression, splitting, direct tensile and elastic modulus tests. It was found that the mixture with a ratio of alkalis of 1.5 and the PVA fiber content of 0.4% had the best workability. The highest compressive strength was obtained in a mixture with alkali activator ratios of 1.5 and 2.0, and with 0.6% fiber addition. The ratio of the tensile (and splitting-tensile) strength to compressive strength was found to increase with the certain amount of PVA fibers and the ratio of the alkali activators. The workability issue and fiber direction in the concrete were the dominant factors influencing the properties of geopolymer concrete.