Alkali-Activated Slag Coatings for Fire Protection of OPC Concrete

Abstract

During a fire, ordinary Portland cement (OPC) systems lose their mechanical properties. For this reason, it is important to find a way to protect it. This study suggested alternative uses of slag and phosphogypsum to produce coatings for fire-resistant applications. Five compositions of 10 mm thick alkali-activated slag coatings were investigated. In these compositions, different amounts of phosphogypsum (1%, 3%, 5%, 7%, and 10%) were used. In the first stage of this study, the residual compressive strength of samples with the coatings based on alkali-activated slag was compared to the results of OPC concrete samples without coatings. The experimental results showed that a higher residual compressive strength of 33.2–47.3 MPa OPC concrete was achieved for the samples with coatings. Meanwhile, the residual compressive strength of the uncoated samples was 32.37 MPa. In the second stage, OPC concrete samples were reinforced with fiberglass polymer (FRP) rods, and they had a similar positive effect on alkali-activated coatings. After exposure to higher temperatures, the pullout tests of the glass FRP bars showed that the adhesion strength was (9.44 MPa) 43.9% higher for the samples with coatings compared to the samples without coatings (6.56 MPa). Therefore, a higher bond strength can be maintained between concrete and FRP bars. Alkali-activated slag with 3% phosphogypsum can be used for the production of fire-resistant coating. These coatings could protect OPC concrete and reinforced concrete with glass FRP bars from fire.

Influencia de la adición de fibra de vidrio AR sobre la resistencia a la compresión del concreto f’c 210 kg/cm2. Una revisión sistemática: 2020 – 2024

“…La inserción de fibras de vidrio AR en el concreto ha marcado un antes y después en términos de resistencia a la compresión, como lo demuestran las investigaciones de Kiele et al (2023). Este estudio reveló que, al incrementar la durabilidad del concreto frente a desafíos extremos como el fuego, se logra no solo una mejora en la seguridad estructural sino también en la longevidad de las construcciones, allanando el camino para el desarrollo de materiales más resistentes y sostenibles (Osman et al, 2023).…”

Badania nad odpornością powłok ochronnych dla betonu na działanie wilgoci atmosferycznej

“…Supplementary cementitious materials, including ultra-dispersed mineral additives, are used to improve the quality of concrete [10,11]. Methods that prevent the occurrence of corrosion by covering the surface with protective materials or creating artificial waterproofing are also effective [12][13][14][15][16].…”

“…Synthesised polymers, whose main chain contains periodic inclusions of metal atoms alongside silicon and oxygen atoms, have properties that are significantly altered by the increased mineral content. These polyorganometallosiloxanes are characterised by high thermal stability [16], which surpasses that of organosilicon polymers.…”

“…At relatively low temperatures, mechanochemical interactions cause polyorganosiloxane to graft onto the surface of silicate particles, forming siloxane-silicate bonds. Condensation reactions complete at temperatures ranging from 573 to 973 K [16].…”

“…However, the integrity of the structure is not violated, although the material becomes porous, turning into ceramics with open porosity of up to 35%. The number of pores decreases sharply in the presence of a vitreous component that fills the pores [16].…”