Numerical simulations to quantify the influence of phase change materials (PCMs) on the early- and later-age thermal response of concrete pavements

This paper employs a numerical simulation strategy to elucidate the influence of phase change materials (PCMs) on the thermal response of concrete pavements. Simulations of both the early- and late-age response of concrete pavements containing microencapsulated PCMs, with considerations of mixture proportions, PCM types, and structural and environmental boundary conditions, are carried out. The latent-heat response of PCMs is explicitly integrated into the model. The early-age simulations show significant reductions in peak hydration temperature and the heating/cooling rates when PCMs, either as a partial replacement of the cement paste or fine aggregates, are incorporated in concrete, resulting in reduced cracking probabilities. Simulations on mature pavements also indicate temperature and curling stress reductions when appropriate PCMs are used. PCM type(s) and dosage, depending on the imposed external temperature regimen, can be chosen based on the model to reduce the magnitude of critical stresses at both early- and late ages. The numerical model thus enables engineers and designers rationally design crack-resistant concrete pavements.