Acrylate based post-acting polymers as novel viscosity modifying admixtures for concrete

• Published in: Construction & building materials 2021-12, Vol.312, p.125414, Article 125414
• Main Authors: Chen, Jian, Qiao, Min, Gao, Nanxiao, Wu, Jingzhi, Shan, Guangcheng, Zhu, Bosong, Ran, Qianping
• Format: Article
• Language: English
• Subjects: Acrylate; Adsorption; Bleeding; Cement paste; Fluidity; Post-acting polymers; Rheology; Viscosity modifying admixtures
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2021.125414

[Display omitted] •Post-acting polymers were utilized as novel VMAs for the first time.•Polymers of different acrylate contents but similar molecular weights were prepared.•The effects of the acrylate segments of the polymers on cement paste were studied.•Viscosity modifying effects of polymers enhance gradually and maintain for long time.•The study overcome the weakness of traditional VMAs. In this work, post-acting polymers were utilized as novel viscosity modifying admixtures (VMAs) for the first time. A series of the random terpolymers containing anionic acrylic acid (AA), nonionic hydroxypropyl acrylate (HPA) and N, N-dimethyl acrylamide (DMAA) was synthesized. By changing the concentration of initiator, the copolymers with different acrylate segment (HPA) contents and similar molecular weights were obtained. The adsorption, fluidity, bleeding and rheological properties of the cement paste containing different copolymers have been discussed. The effects of the acrylate segments of the copolymers on the properties of cement paste were studied. The results show that the post-acting polymers are hydrolyzed and adsorb on the cement particle surface gradually, meanwhile decrease the bleeding and stabilize the cement paste slowly. The viscosity modifying effects of the post-acting polymers on cement enhance gradually and maintain for a long time.