Premium
Effect of cross‐linked polycarboxylate‐type superplasticizers on the properties in cementitious system
Author(s) -
Liu Hailu,
Pang Hao,
Ou Juhua,
Zhang Lei,
Dai Yongqiang,
Liao Bing
Publication year - 2014
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.40856
Subject(s) - superplasticizer , materials science , cementitious , ettringite , cement , slump , rheology , composite material , zeta potential , chemical engineering , nanoparticle , nanotechnology , portland cement , engineering
Fluidity and slump loss are main technical indicators for the quality of concrete. They are related to the dispersion of cement and hydration process, and are greatly affected by the structure of superplasticizers (SPs). For the purpose of obtaining SPs with excellent fluidity and slump retention, water‐soluble cross‐linked polycarboxylate ether copolymers (CLPCs) of acrylic acid and alkenyl alcohol type polyoxyethylene ether were synthesized. In order to gain full understanding of the effect of cross‐linked SPs on the properties in cementitious system, properties of the new SPs in cement paste were compared to those of traditional ones without cross‐linking agents. Mortar tests showed that CLPC performed obvious slow‐release function and kept about 10 mm higher than its initial paste flow after 150 min, while PC incurred loss of 15 mm after 150 min. Adsorption of CLPC on cement resulted in zeta potential being roughly the same as that in the case of PC, and enabled more effective slump retention to cement suspensions by rheological property tests. Ettringite peaks disappeared for CLPC on 1‐day curve and reappeared after 35 days, and the intensity of CH peaks for CLPC appeared weaker than Blank and PC after 1 day. The microstructure of CLPC after 1 day showed a very dense structure of smaller and thinner crystallites, which indicated that the early hydration was greatly delayed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40856.