Title: Fresh Properties of High-Volume Fly Ash Self Consolidating Concretes

Author(s): M. Sahmaran, I.O. Yaman, and M. Tokyay

Publication: Symposium Paper

Volume: 235

Issue:

Appears on pages(s): 189-202

Keywords: fly ash; high volume fly ash; rheology, self consolidating concrete; workability

DOI: 10.14359/15909

Date: 3/22/2006

Abstract:
Self consolidating concrete (SCC) is defined as a concrete with high flowability and good cohesiveness which is compacted under its own weight without the need of any vibration effort. For a successful SCC, higher amounts of binders are used together with the new generation of superplasticizers to achieve the necessary fresh properties. Recent investigations show that the use of mineral admixtures such as fly ash improves the workability properties of SCC. Replacing part of the binder with fly ash not only causes a reduction in the dosage of cement and superplasticizer but also improves the durability properties of SCC. Within the scope of this research, SCC with high volumes of high-lime and low-lime fly ash replacements was produced. Properties of SCC in the fresh and hardened states with both fly ash types are investigated. The fresh properties of the concretes were observed through slump flow and diameter, V-funnel time, L-box, GTM sieve stability, setting times and the rheological parameters relative yield stress and relative plastic viscosity. The strength properties included the compressive strength at 28, and 90 days. It was observed that the geometry and surface characteristics of the fly ash affected the workability properties of SCC mixtures. As a result, it was possible to produce SCC incorporating fly ash replacement volumes of up to 70% with sufficient strength.