Abstract

Canada has a cold climate that experiences freezing temperatures over long periods of the year,
which impedes in-situ construction activities or puts them to a halt, resulting in considerable
socioeconomic losses. Hence, construction companies have shifted to precast concrete systems in
order to continue work throughout this harsh weather condition. However, applying heat curing
and controlling the concrete temperature during the fabrication process at a favorable temperature
of 10°C to 32°C is the main challenge for the precast concrete sector. Therefore, in this dissertation,
mixtures for selected construction materials related to precast industry (i.e. cement-based and
alkali activated concrete) were optimized/developed to have less energy intensive curing process
with the aid of phase change materials (PCMs). Microcapsulated phase change materials (MPCMs)
were used in order to avoid chemical interaction between PCMs and binding materials. The
experimental program focused on evaluating fresh, mechanical, thermal and durability
performance for these construction materials with different types and additional rates PCMs.
Mixtures without PCMs were also test for comparison purpose. Results illustrated the role of
MPCMs in storing and releasing the heat either generated from the hydration process or applied
during curing process. The changes in heating rates during hydration reaction induced by MPCMs
had influence of hydration kinetics for used binding materials. The performance of MPCMs will
be alerted based on the binding materials. Thermal properties for tested construction materials,
especially heat capacity, had enhanced by the addition of MPCMs. However MPCMs addition had induced reduction in strength, adjusting mixtures design and producing dense microstructure would help in minimize this adverse effect. It is anticipated that these results will pave the way for wider implementation for PCMs in construction materials, which in turns will result in both economic and environmental benefits on the industrial and social levels. On the industrial level, this advance will speed up the production process while saving costs associated with heat curing leading to high production-cost efficiency and maximized profits. On the social level, it will reduce the carbon footprint for the precast concrete industry through decreasing its energy demand and fossil fuel consumption leading to a better life quality for Canadians.