Interaction of water with supplementary cementitious materials -
Hydration mechanism, microstructure and moisture transport
Opponent: Professor, Kefei Li, Department of Civil Engineering, Tsinghua University, Beijing, China
Examinator: Professor, Bijan Adl-Zarrabi, Byggnadsteknologi, Arkitektur och samhällsbyggnadsteknik, Chalmers
Huvudhandledare: Professor, Luping Tang, Byggnadsteknologi, Arkitektur och samhällsbyggnadsteknik, Chalmers
Biträdande handledare: Professor, Zhenghong Yang, School of Materials Science and Engineering, Tongji University, Kina
Översikt
- Datum:Startar 16 juni 2023, 08:30Slutar 16 juni 2023, 14:30
- Plats:Tongji University, Kina och Zoom
- Språk:Engelska
Lösenord till Zoom: 230616
Abstract:
Concrete is the essential material for the construction of many structures, so it is the second most used material in the world after water. Cement, being the primary material in the production of concrete, poses a significant challenge to achieving carbon neutrality in the construction sector, due to the emissions generated during its manufacturing process. Nowadays, the most feasible and mature way to reduce emissions from cement production is to replace it partially by supplementary cementitious materials (SCMs). The use of SCMs reduces the amount of cement needed in concrete, which in turn reduces CO2 emission during cement production and decreases the overall carbon footprint of concrete.
Examples of SCMs include fly ash, slag and limestone powder. Some of them are industrial by-products that would otherwise be disposed of in landfills, but instead can be used to create stronger and more durable concrete. Although benefits of using SCMs in concrete extend beyond just reducing the carbon footprint, the use of diverse SCMs induce difficulties in controlling and predicting the performance of concrete. When using traditional methods to predict the right time for laying or finishing concrete containing SCMs, the inaccurate predictions will result in humidity-related issues such as cracking and mould growth, causing a threat to human health and safety. Therefore, a comprehensive understanding of the properties of the blended concrete is needed to establish appropriate models for better control the performance.
This dissertation has conducted an in-depth study on exploring the impact of SCMs and related additives on hydration of cementitious materials and microstructure change, and their relationship to transport processes. A device was designed to continuously monitor the effect of SCMs on hydration-induced structure change, and it was subsequently upgraded to monitor the hardening process of concrete containing SCMs. The work in this dissertation contributes to promote the high-quality use of SCMs in sustainable concretes.