Abstract
Alternative (i.e., non-Portland) cements, such as alkali-activated materials, have gained significant interest from the scientific community due to their proven CO2 savings compared with Portland cement together with known short-term performance properties. However, the concrete industry remains dominated by Portland cement-based concrete. This Letter explores the technical and non-technical hurdles preventing implementation of an alternative cement, such as alkali-activated materials, in the concrete industry and discusses how these hurdles can be overcome. Specifically, it is shown that certain technical hurdles, such as a lack of understanding how certain additives affect setting of alkali-activated materials (and Portland cement) and the absence of long-term in-field performance data of these sustainable cements, can be mitigated via the use of key molecular- and nano-scale experimental techniques to elucidate dominant material characteristics, including those that control long-term performance. In the second part of this Letter the concrete industry is compared and contrasted with the electricity generation industry, and specifically the transition from one dominant technology (i.e., coal) to a diverse array of energy sources including renewables. It is concluded that financial incentives and public advocacy (akin to advocacy for renewables in the energy sector) would significantly enhance uptake of alternative cements in the concrete industry.
Highlights
The quest for alternative cements that are more sustainable than Portland cement is motivated by the large CO2 emissions associated with Portland cement manufacturing around the world
Given the CO2 emissions associated with Portland cement manufacturing and the existence of lower‐CO2 alternative cements with proven performance, it often comes as a surprise to the general public that these sustainable alternatives have yet to substantially penetrate the concrete industry
The technical and non‐technical hurdles preventing uptake of alternative cements in the concrete industry have been explored, where it was shown that key insight obtained from select molecular‐ and nano‐ scale experimental techniques can help overcome technical challenges relating to short‐term performance and long‐term durability
Summary
The quest for alternative (i.e., non‐Portland) cements that are more sustainable than Portland cement is motivated by the large CO2 emissions associated with Portland cement manufacturing around the world. Given the lower extent of nanocrystallinity of the real C‐(N)‐ A‐S‐H gel in AAS, together with the known amorphicity of N‐ A‐S‐(H) gel in AAMK, there is the opportunity to deliberately increase the nanoscale ordering of these gels with the aim to improve their thermodynamic stabilities and increase their resistance to chemically‐induced degradation Careful control of this behavior would be necessary to ensure that an increase in crystallinity occurs during the initial formation of the paste whilst the material is still compliant, since later‐age crystallization can lead to cracking and loss of mechanical strength (cf., delayed ettringite formation in Portland cement paste). Projections by the U.S Energy Information Administration (2019) have renewables (including hydroelectricity) at 31% by 2050 with solar photovoltaics being responsible for 15% of total electricity generation [38]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
