Title: The Use of High-Range Water-Reducers in Concrete Containing Fly Ash and Ground, Granulated Blast-Furnace Slag
Author(s): W. M. Hale, I A. Ling, I D. Bush, Jr., and B. W. Russell
Publication: Symposium Paper
Appears on pages(s): 217-232
Keywords: air entraining agents; blast furnace slag; chemical admixtures; fly ash; high range water reducers; mechanical properties; slump loss; supplementary cementitious materials
This study examined the effects of using a high range water reducer (HRWR) on concrete with pozzolan replacement. The HRWR was used in two ways: 1) to increase the workability of mixtures with otherwise unchanged mixture proportions, 2) to pro-duce mixtures with workability similar to those without HRWR but with lower w/cm. For the first goal, HRWR dosages were determined that would increase the slump of mixtures to approximately 150 mm. For the second goal, concretes were produced with water to cementitious material ratio (w/cm) reduced by 0.03 (as compared to the control mixtures) but with slumps in the 25 to 75 mm range. Comparisons were made between the HRWR mixtures and with control mixtures without HRWR. Only two types of mixtures were studied: 1) 15 percent Class C fly ash replacement and 2) 25 percent slag replacement. The research results showed that use of HRWR in mixtures containing ground granulated blast furnace slag and in mixtures containing fly ash generally improved compressive, flexural, and tensile strengths (to varying degrees), even for mixtures with unchanged w/cm.