Low-Carbon Concrete Based on Binary Biomass Ash–Silica Fume Binder to Produce Eco-Friendly Paving Blocks

Abstract

The civil construction industry consumes huge amounts of raw materials and energy, especially infrastructure. Thus, the use of eco-friendly materials is indispensable to promote sustainable development. In this context, the present work investigated low-carbon concrete to produce eco-friendly paving blocks. The binder was defined according to two approaches. In the first, a binary binder developed with eucalyptus biomass ash (EBA) and silica fume (SF) was used, in total replacement for Portland cement. In the second, the mixture of residues was used as a precursor in alkali-activation reactions, forming alkali-activated binder. The experimental approach was carried out using five different mixtures, obtained by varying the amount of water or sodium hydroxide solution. The characterization of this new material was carried out using compressive strength, expandability, water absorption, deep abrasion, microstructural investigation, and organic matter degradation potential. The results showed that the EBA-SF system has a performance compatible with Portland cement when used as an alternative binder, in addition to functioning as a precursor to alkali-activated concrete. The blocks produced degraded organic matter, and this degradation is more intense with the incidence of UV. In this way, the EBA-SF binder can be successfully used for the manufacture of ecological paving blocks with low carbon emissions.

Sustainable transition towards biomass-based cement industry: A review

“…Finding alternative materials for clinker substitution is a key decarbonisation lever in cement manufacturing, as clinker production alone is responsible for 50 to 60% of total GHG emissions. So far, industrial by-products like blast furnace slag [19,78], coal fly ash from thermal power plants [78,79], silica fume [78,80] and pozzolanic glass [78] have been used to replace clinker as supplementary cementitious materials. However, the availability of coal fly ash, a commonly used cementitious material, is expected to decrease significantly in the future due to decommissioning of several coal-fired power plants [27].…”

Eco-Friendly Asphalt Approach for the Development of Sustainable Roads

“…As a closed space, the functional requirements of the tunnel pavement are very different from ordinary pavements, e.g., a higher requirement on the reduction of the pavement noise, proper light reflection to ensure safety and save tunnel lighting energy, closure of the construction process, better pollutant discharge and air purification [24]. The construction industry consumes a large number of resources and energy, in contrast to other sectors of the contemporary economy [25]. The demand for more sustainable solutions has led an ever-growing number of stakeholders to being committed to pursue the principles of sustainability in pavement management.…”

Development of Photocatalytic 3D-Printed Cementitious Mortars: Influence of the Curing, Spraying Time Gaps and TiO2 Coating Rates

“…Different methodologies have been used to apply semiconductors into cementitious composites, in order to endow them photocatalytic properties [24]. Volume incorporation during the mixing process (by, e.g., [3,5,22,23]), binder modification [4,15], using the catalytic carrier in the cementitious mixture [24,25], and surface coating by spraying semiconductor particles (by, e.g., [3,5,17,24,26,27]) are some methods used for the photocatalytic functionalization. The coating method by spraying semiconductor particles is recognized as the most efficient and easiest application method for using semiconductors compared to other approaches [17,24].…”

“…Regarding the evaluation techniques to assess the photocatalytic efficiency in a broad range of materials (including Civil Engineering Materials-such as asphalt and cementitious), researchers usually carry out methodologies in order to perform the photodegradation of organic compounds (for example, RhB, Methylene Blue, Methylene Orange, among others) (by, e.g., [3,4,9,14,16,22,26,27]). Moreover, multiple factors can affect the photocatalytic behaviour and influence its performance, such as variations in specimens' size, different methodologies for applying pollutants and semiconductor materials and their contents, the light wavelength (UV, visible light, and sun light simulation), and the corresponding power density, the types of dyes and their concentrations, the volume of the dye solution (in the case that dye is used as a pollutant), the time duration of the test, the curing time of the specimens, among others.…”