Title: Effect of Superplasticizer and Viscosity-Increasing Admixture on Properties of Lightweight Aggregate Concrete

Author(s): T. Kawai and T. Okada

Publication: Symposium Paper

Volume: 119

Issue:

Appears on pages(s): 583-604

Keywords: admixtures; compatibility; gels; high-strength concretes; lightweight aggregate concretes; plasticizers; segregation; viscosity; workability; Materials Research

DOI: 10.14359/2563

Date: 9/1/1989

Abstract:
Describes the effect of a superplasticizer and a viscosity-increasing admixture on the properties of high-strength lightweight aggregate concrete with a slump larger than 25 cm. Firstly, the compatibility between typical superplasticizers and the viscosity-increasing admixture was investigated. It has been reported that compatibility between sulfonated naphthalene formaldehyde condensate-typesuperplasticizer and a viscosity-increasing admixture was sometimes poor because of the gel production. It was found from experiments that maximum allowable dosages exist that do not cause the gel. Secondly, the effect of the superplasticizer and the viscosity-increasing agent on the properties of the concrete was investigated. The superplasticizer, containing a polymer called PVA, showed that larger dosages resulted in greater superplasticizing effect and constant slump flow. Furthermore, the viscosity-increasing admixture could prevent the concrete from harmful segregation. It was concluded that the degree of segregation depends on the dosages of super plasticizer and viscosity-increasing admixture. Furthermore, this research made it possible to obtain a high-strength (more than 41 Mpa) lightweight aggregate concrete with excellent flowability.