Title: Experiences in the Use of Superplasticizers in Some Special Fly Ash Concretes
Author(s): Kirsten Eriksen and
Publication: Symposium Paper
Appears on pages(s): 1-20
Keywords: coarse aggregates; compressive strength; fly ash; high-strength
concretes; mix proportioning; naphthalene compounds;
plasticizers; portland cements; water-reducing agents; workability.
Use of a naphtalene-based superplasticizer at high dosages in concretes made with fly ash (100-150 kg/m3) and a moderate content of portland cement (250-300 kg/m3) results in great water reductions and high strengths (75-80 MPa after 28 days) for concretes with normal workability (slump 5-10 cm). Laboratory investigations concerning mixture proportions and pro-perties of the fresh and hardened concretes with a discussion of physical and chemical influences of the use of the superplasticizer are presented. Increasing problems with the supply of good, in-expensive, natural coarse aggregates may be solved through combined additions of superplasticizers and fly ash to the concrete. This paper further presents experimental evidence of mixture proportions and phy-sical data for socalled "sand-concrete", i.e. concrete without coarse aggregates but with "normal" contents of portland cement and water obtained by the addition of rather large amounts of fly ash and superplasticizers.