In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Become an ACI Member
Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete.
ACI World Headquarters
38800 Country Club Dr.
Farmington Hills, MI
ACI Middle East Regional Office
Second Floor, Office # 02.01/07
The Offices 02 Building, One Central
Dubai World Trade Center Complex
Phone: +971.4.516.3208 & 3209
Feedback via Email
Home > Publications > International Concrete Abstracts Portal
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
Title: Influence of Silica Fume on the Rheology of Cementitious Paste
Author(s): H. Man and H. Justnes
Publication: Special Publication
Appears on pages(s): 427-442
Keywords: gel strength; rheology; silica fume; viscosity; yield stress
Abstract:The influence of silica fume (SF) on the plastic viscosity, yield point and gel strength of cementitious paste has been studied. A super-plasticizer based on polyacrylate with grafted polyether chains (SSP) was used. The effect of delayed addition of super-plasticizer versus addition with the mix water was investigated as well as the effect of densified versus untreated silica fume. Inert limestone slurries with SF replacement were used as comparison. The results showed that there was not much to gain in terms of lower shear stress in flow curves by delayed addition of this particular SSP. The plastic viscosity had a de-creasing tendency with increasing SF replacement, while yield stress was rather constant. Plastic viscosity increased with increasing time. There was a substantial increase in 10 min gel strength with increasing SF replacement. Gel strength was lower for mixes with densified SF versus untreated SF. Delayed SSP addition reduced gel strength for cementitious pastes with 10% SF. Neutral limestone pastes with increased SF replacement had increasing gel strength from 6 vol% replacement. Densified silica fume gave 10 times less gel strength than untreated SF. Increasing pH from 8 to 13.2 in limestone slurries with 10 vol% SF increased the shear stresses substantially.
Click here to become an online Journal subscriber