Promoting the use of Fe-rich slag in construction: Development of a hybrid binder for 3D printing. (April 2023)

• Record Type: Journal Article
• Authors: Beersaerts, Glenn; Hertel, Tobias; Lucas, Sandra; Pontikes, Yiannis
• Is Part Of: Cement & concrete composites. Volume 138(2023)
• Publication Date: 2023-04
• Subjects: 3D printing -- Non-ferrous metallurgy slag -- Alkali-activated materials -- Hybrid mortars -- Rheology -- Alternative binders; NFMS Non-ferrous metallurgy slag -- OPC Ordinary Portland cement -- GGBFS Ground granulated blast furnace slag -- SF Silica fume -- FA Fly ash class F -- FL Fine limestone powder -- CS Coarse quartz sand -- SP Superplasticizer -- PCE Polycarboxylate ether -- MF Microfibers -- CSA Calcium sulphoaluminate cement -- L/S Liquid over all solids mass ratio -- L/B Liquid over binder mass ratio -- S/B Sand over binder mass ratio -- E-mod Dynamic E-modulus -- SEM Secondary electron microscope -- SCM Supplementary cementitious materials -- IP Inorganic polymer -- AAM Alkali activated material; Composite-reinforced concrete -- Periodicals; Concrete -- Periodicals; Composite materials -- Periodicals; Composites de ciment -- Périodiques; Béton -- Périodiques; Composites -- Périodiques; Béton léger -- Périodiques; Cement composites; Composite materials; Composite-reinforced concrete; Concrete; Lightweight concrete; Periodicals; Electronic journals; 620.135
• DOI: 10.1016/j.cemconcomp.2023.104959
• Languages: English
• ISSNs: 0958-9465

Abstract

Abstract: The construction sector is responsible for significant CO2 emissions, especially due to the production of ordinary Portland cement (OPC). One option to decrease CO2 emissions is to print mortar made from an alternative binder. A precursor was used consisting of mainly non-ferrous metallurgy Fe-rich slag and a minor amount of OPC (<16 wt%), which forms upon alkali-activation a hybrid binder. A 3D-printable hybrid mortar was developed in a step-by-step performance-based approach, with a focus on the fulfilment of criteria relevant for 3D printing: shear-thinning, high yield stress, and stiffness development. The criteria to be met were determined using a commercially available 3D-printable OPC-mortar. Several raw materials were introduced to develop a hybrid mortar with a particle packing that positively influenced the pumpability and buildability. The effect of the precursors and superplasticizer on reactivity was investigated. The final mortar reached the printing criteria, offering a suitable alternative to 3D-printable OPC-mortars. Highlights: An Fe-rich slag hybrid mortar was developed with a continuous particle packing. Pumpability, printability and buildability criteria were identified with printable OPC-based mortar. The developed mortar met print criteria and consists of minor amount of cement. The slag contributed to the binder strength and different binder types formed.