The civil construction and infrastructure sectors are known for their high environmental impact. Most of this impact is related to the carbon dioxide (CO₂) emissions from Portland cement. As a sustainable alternative, alkali-activated binders (AABs) are explored for their potential to replace traditional binders. This research focused on AAB formulations using steel industry byproducts, such as Baosteel’s slag short flow (BSSF), coke oven ash (CA), blast furnace sludge (BFS), and centrifuge sludge (CS), as well as fly ash (FA) from a thermoelectric plant. Byproducts were characterized through laser granulometry, Fourier transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM), followed by the formulation of AABs with different precursor ratios. After 28 days, the compressive strength was obtained for each formulation. Based on the compressive strength tests, two binary mixtures were selected for microstructural and chemical analyses through XRF, FTIR, and SEM. CA demonstrated the greatest potential for use in binary AABs based on BSSF, as it presented a higher source of aluminosilicates and smaller particle sizes. The formulations containing BSSF and CA achieved compressive strengths of up to 9.8 MPa, while the formulations with BSSF and FA reached 23.5 MPa. SEM images revealed a denser, more cohesive matrix in the FA-based AAB, whereas CA-based AABs showed incomplete precursor dissolution and higher porosity, which contributed to the lower mechanical strength of CA-based AABs. These findings highlight the critical role of precursor selection in developing sustainable AABs from industrial byproducts and demonstrate how different formulations can be tailored for specific applications.

This study aimed to evaluate the thermal conductivity and sound absorption performance of panels based on coconut fiber and castor oil resin, with potential application in walls, roofs and floors, considering their alignment with current standards. Panels composed of a mass ratio of 85% fiber and 15% castor oil resin were produced by centrifugation mixing and pressing to achieve thickness of 5 cm. The produced panels were assessed at densities of 60 kg/m³, 80 kg/m³, and 100 kg/m³ and were evaluated by grammage, moisture absorption, longitudinal tensile strength, thermal conductivity, and sound absorption coefficient. The production process proved to be suitable. The thermal conductivity values ranged from 0.061 W/mK to 0.064 W/mK similar values to commercial products such as rock wool (0.046 W/mK) and glass wool (0.045 W/mK). Moreover, the sound absorption performance resembled that of insulating materials like melamine foam, demonstrating better performance at low emission frequencies.

Alkali-activated concretes (AAC) offer an alternative to Portland cement concretes, with high strength and low CO₂ emissions. However, common durability testing for conventional concrete may not suit AAC. This study aimed to verify the suitability as durability characterization tests for chloride migration, electrical resistivity, and water penetration under pressure, commonly applied to conventional concretes, in AAC based on fly ash and BOF steel slag. A comparison with a Portland cement-based concrete was also done. Tests of penetration of water under pressure; electrical resistivity; chlorides migration; and ion chromatography in the solutions before and after chlorides migration were performed. The findings revealed that while AAC exhibits low permeability, its high conductivity results in elevated electrical currents during chloride migration tests, potentially overestimating chloride migration. Ion chromatography indicated lower actual chloride migration, suggesting that electrical current is not only linked to chloride migration.