Title: Development of New Superplasticizer Providing Ultimate Workability
Author(s): D. Hamada, T. Hamai, M. Shimoda, M. Shonaka, and H. Takahashi
Publication: Symposium Paper
Appears on pages(s): 31-50
Keywords: adsorption; cement; EO chain; hyper-branched polymer; plastic viscosity; rheology; superplasticizer; yield value; workability
Recently, the concrete workability has become regarded as much more important due to large demands for high durable concrete with low water content and unstable quality of concrete ingredients. The new superplasticizer was found to provide better workability controlling the rheological properties of the fresh concrete than the previous polycarboxylate type superplasticizers regardless of the quality of concrete ingredients. The framework structure of the new superplasticizer was a hyper-branched polymer in which specific function monomers were co-polymerized. The new polymer of the hyper-branched structure was more condensed than that of polycarboxylate type polymers and was highly adsorptive to cement particles, which made a higher density of the polymer adsorption onto cement surfaces possible. This dense and strong adsorption of the superplasticizer polymer molecules provided the unique rheological properties of the concrete or the mortar such as the lower viscosity of the concrete giving much easier handling. This new superplasticizer also provided the robustness against varieties of the concrete ingredients qualities. This superplasticizer for new generations has already been made practicable successfully for several constructions, and this technology will bring various possibilities and merits in concrete construction fields such as shortening the construction period thanks to better workability.