Article 2022 · 9 citations

High temperature resistant restoration mortar with fly ash and GGBFS

Demircan, Ruya Kilic, Kaplan, Gokhan, Celik, Damla Nur

Abstract

Nowadays, the development of sustainable building materials is of loom large in for the preserve resources and reducing CO2 emission and environmental pollution effects. Exposure to fire or other high temperatures of mortars produced with calcium-based binders (cement or hydraulic lime) adversely affects their mechanical properties. In addition, the effect of high temperature may cause a change in the pore structures, causing cracking and spalling. Protecting the integrity of historical buildings exposed to high temperatures is important for cultural sustainability. In this study, natural hydraulic lime (NHL) used as a binder in mortars was replaced with 15, 30 and 60% fly ash (FA) and granulated blast furnace slag (GBFS). In the mixtures, 1.5% (by volume) polypropylene fiber (PF) was also used. Test results reveal that while the mortars' workability increased as the FA and GBFS content increased, PF decreased the flow diameters of the mortars. It has been determined that the paste content affects the porosity and water absorption rates of mortars. With the addition of FA content, paste content increased and porosity reduced. Compressive strength over 10 MPa was obtained by using 30% FA in 90-day lime mortars. As the addition of GBFS, the compressive and flexural strength were negatively affected. PF has reduced the porosity and water penetration depth of the mortars thanks to its micro filler effect. FA-based mixtures were more resistant to high temperatures than GBFS-based mixtures. Compressive strength was measured between 4.3 and 8.6 MPa after 600 degrees C temperature in FA-based mixtures. In fibrous mixtures, increment of mass loss was more with high temperature. C-S-H gels were observed in XRD and SEM analyzes of mortars exposed to high temperatures. PF was observed in stereomicroscope images of mixtures exposed to 200 degrees C. Since the porosity of the mortars is relatively high (19.7%-30.8%), the PF in the mixtures exposed to 200 degrees C did not melt completely but was damaged. As a result, it would be more appropriate to use 30% of FA and 15% of GBFS in NHL mortars.

Keywords

durability sustainability blast furnace slag fly ash polypropylene fiber restoration mortar NATURAL HYDRAULIC LIME BLAST-FURNACE SLAG HIGH-PERFORMANCE CONCRETE FIRE-DAMAGED CONCRETE HARDENED CEMENT PASTE MECHANICAL-PROPERTIES POLYPROPYLENE FIBERS DURABILITY PROPERTIES COMPRESSIVE STRENGTH ELEVATED-TEMPERATURE

WoS Categories

Construction & Building Technology Green & Sustainable Science & Technology Materials Science, Multidisciplinary

Sustainable Development Goals

Responsible Consumption and Production

Citation

Journal: JOURNAL OF SUSTAINABLE CEMENT-BASED MATERIALS
Year: 2022
Volume: 11
Issue: 6
Pages: 418-438
ISSN: 2165-0373
eISSN: 2165-0381
DOI: 10.1080/21650373.2021.1992682
WoS UID: WOS:000719750200001

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