Life cycle assessment of geopolymer concrete

Recent progress in low-carbon binders

“…The trend in the academic literature recently has therefore been toward regionally-specific (or very localized) assessments of AAMs for use in particular applications or concrete/mortar products in the Americas [305][306][307], Europe [308][309][310], and Australasia [311,312]. The general trend observed in these studies is that AAMs offer greenhouse emissions savings compared to a Portland cement baseline, and usually on the order of 40-60%, but somewhat increased the environmental impact in other non-greenhouse categories, such as abiotic depletion, ozone layer depletion, fresh and marine water ecotoxicity, and human toxicity, that are considered in the lifecycle assessment process.…”

Development of precast geopolymer concrete via oven and microwave radiation curing with an environmental assessment

“…As aforementioned by other studies (Dal Pozzo et al, 2019;Duxson et al, 2007b;McLellan et al, 2011), geopolymer samples present a greater sustainability compared with PC counterparts, and some studies even indicated that the energy consumed and carbon footprints emitted by geopolymer production were significantly lower in comparison with those associated with PC sample preparation (Hassan et al, 2019;Sandanayake et al, 2018;Taylor, 2013), which were mainly associated with the avoidance of limestone calcination (Dal Pozzo et al, 2019), however, (Ma et al, 2018;Ouellet-Plamondon and Habert, 2015) also indicated that not all alkali-activated binders presented a lower global warming potential (GWP) in comparison with blended cements via Feret equation, and they indicated that one-part geopolymer seemed to be a more promising binder concerning sustainability. Meanwhile, compared with the precursors, the production of alkali used in the preparation of samples was still an energyintensive process, therefore, (Dal Pozzo et al, 2019) suggested the use of sustainable energy supplies such as hydrothermal route in its production, whereas (Salas et al, 2018) indicated that using NaOH in geopolymer concrete, which was produced from solar salt, would led to a great reduction in the overall environmental impacts related with sample preparation. Recently, reactive magnesia has been used as the activator in alkali-activated binders (Jin et al, 2013;Jin et al, 2014) due to the lower environmental impacts associated with its production Unluer, 2016, 2017), and the results also indicated that use of reactive magnesia could alleviate the shrinkage of samples due to its expansion as a result of magnesia hydration (Jin et al, 2013;Jin et al, 2014).…”

“…clearly indicates that geopolymer samples made by GGBS and PFA show much lower overall environmental burdens in comparison with PC samples with the same w/b ratios, which could be attributed to the relatively lower inputs and outputs associated with the collection of PFA and GGBS as they were regarded as pure industry waste in this study. Though the content of alkali used is much lower than precursors during geopolymer preparation, it still occupied the majority of environmental impacts as the manufacturing process of these chemicals such as NaOH was still energy-intensive, and more sustainable approaches should be adopted with respect to the alkali production(Dal Pozzo et al, 2019;Salas et al, 2018). Besides, the figure also shows that the points of fossil fuels are the highest than the rest environmental impacts in all these three groups.…”

Alkali-Activated Hybrid Concrete Based on Fly Ash and Its Application in the Production of High-Class Structural Blocks

“…Several authors have reported that, in general, alkali-activated concretes have a significantly lower carbon footprint than conventional OPC-based concrete. Robayo-Salazar et al [27] reported a 44.7% reduction for a binary concrete based on a natural pozzolan (70%) and blast furnace slag (30%), as well as Salas et al [28] and Teh et al [29] with values of 64%, 32%, and 43% for concrete based on natural zeolite, fly ash and blast furnace slag, respectively. Figure 16 shows the GWP values for the hybrid concrete (90% FA-10% OPC) (243.…”