Research on Toughness and Modification Mechanism of <i>In Situ</i> Toughening Mortar

Abstract

Small molecular monomer and initiator were added to cement mixture, in situ polymerization had occurred under the action of initiator with the cement hydration, and polymer network was produced, and thus the toughness of cement paste was improved. The toughness of in situ toughening mortar had been measured through flexural/compressive ratio, and modification mechanism had been revealed through MIP, SEM and TG-DTG. The results show that, flexural/compressive ratio of in situ toughening mortar has been enhanced greatly compared with reference; Many polymer films are formed in hardened cement mortar, and hydrolysis product of polymer can react with cement hydration product Ca(OH)2. Physical adhesion between polymer films and cement hydration products and chemical bonding between polymer and cement hydration products are primary causes to improve toughness of cement mortar.