Optimization and mechanical-physical characterization of geopolymers with Construction and Demolition Waste (CDW) aggregates for construction products. (20th December 2020)

• Record Type: Journal Article
• Authors: Panizza, Matteo; Natali, Marco; Garbin, Enrico; Ducman, Vilma; Tamburini, Sergio
• Is Part Of: Construction & building materials. Volume 264(2021)
• Publication Date: 2020-12-20
• Subjects: Geopolymers -- Alkali-Activated Materials (AAM) -- Construction and Demolition Waste (CDW) -- Building Materials -- Recycled Aggregates -- Mortar -- Concrete -- Compressive strength -- Tensile strength -- Shrinkage; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.120158
• Languages: English
• ISSNs: 0950-0618

Abstract

Graphical abstract: Highlights: Geopolymers with CDW aggregates were optimized for producing architectural panels. Final materials were characterized from a mechanical and physical standpoint. Aspect ratio and size of specimens were compared to concrete/mortar provisions. Splitting was correlated to compressive strength through numerous tested geopolymers. Recyclability of geopolymers as waste aggregates was preliminarily assessed. Abstract: The paper presents the mechanical and physical characterization of a metakaolin-slag-fly ash-potassium silicate geopolymer mortar embedding inorganic recycled aggregates from Construction and Demolition Waste (CDW). The binder was holistically optimized to comply with the pilot plant requirements for producing architectural panels of satisfactory quality, among them: reduced viscosity, minimum open time of 1 h, use of commercial reagents, sufficient strength and limited shrinkage. Size and aspect ratio of small scale cylindrical specimens were investigated in compression, comparing the performance of tested geopolymers to available provisions for natural rocks, cement concrete and mortars. Empirical correlations between compressive and splitting tensile strength were calibrated through the results of about 130 geopolymer mixtures produced in former and current activities. Lastly, the suitability of reusing geopolymers at their end-of-life as recycled aggregates in a new geopolymer production was preliminarily assessed to explore the feasibility of a closed-loop process.