Title: Influence of Temperature on Fluidity of Cement Paste Containing Superplasticizer with Polyethylene Oxide Graft Chains
Author(s): T. Nawa, H. Ichiboji, and M. Kinoshita
Publication: Symposium Paper
Appears on pages(s): 181-194
Keywords: adsorption; hydration; superplasticizer
The variation in the fluidity of normal portland cement pastes containing Synopsis : comb-like graft polymers was investigated as a function of temperature ranging from 10 to 30 ‘C, in order to understand the mechanism of change in the fluidity of concrete with ambient temperatures. The polymers were methacrylic graft copolymers with polyethylene oxide graft chain produced by using the molecule design technique. In this way we prepared three different types of copolymers. Hydration of cements and adsorption of graft copolymers on cements were studied for analysis. The fluidity study indicated that the flow value of cement paste immediately after mixing, depended remarkably on temperature and the paste flow value at 20~ tended to the lowest. On the other hand, the flow loss became larger with increasing temperature. Furthermore, the influence of temperature on paste flow and flow loss of cement paste decreased with increasing length of polyethylene oxide graft chains. The interpretation of results is discussed in terms of influence of temperature on steric repulsion between cement particles using the data of the amount of both adsorbed polymer and deposited hydration products.