Bis-hydroxyethyl terephthalate cementitious composites properties: A comparative study including hydrogen bonding mechanism with the dioctyl terephthalate

Functionalized materials are advantageous in terms of imparting self-healing properties to cementitious composites by filling voids and cracks. High-purity bis-hydroxyethyl terephthalate (BHET) can be obtained by depolymerization of waste polyethylene terephthalate, and has great potential as a self-healing additive for the construction industry. BHET cementitious composites have higher values for ultrasonic-pulse velocity and calcium hydroxide content, of 33.47% and 91.71%, respectively, and have lower values for water-absorption percentage and porosity - of 39.66% and 15.66%, respectively - in comparison to dioctyl terephthalate (DOTP) cementitious composites. One of the most important findings of this study is that hydrogen bonds formed in BHET cementitious composites play a crucial role in filling cracks and preventing the agglomeration of cement particles through electrostatic attraction. It was concluded that BHET with hydroxyl groups are important alternatives for use in crack healing. (C) 2020 Elsevier Ltd. All rights reserved.