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: Segregation Characteristics of Concrete Containing a High-Range Water-Reducing Admixture
Author(s): T. Soshiroda
Publication: Special Publication
Appears on pages(s): 121-138
Keywords: aggregates; placi
admixtures; aniso tropy; bl
; fresh concretes; hardened
ng; plasticizers; remolding
es; mix prop
Abstract:The segregation tendency of concrete containing a high-range water-reducing admixture and its effects on the homogeneity of the concrete after hardening have been studied. Segregation during placing was investigated by means of a modified remolding test. The clearance of the inner ring in Powers' testing apparatus had been reduced to restrict the movement of concrete more severely for measuring workability of the concrete with high slump. After jigging was complete, the degree of segregation of coarse aggregate was examined by comparing the mass of coarse aggregate inside of the ring with that outside. Segregation during and after placing, including bleeding, was investigated by examining the variation of internal structure of hardened concrete caused by segregation and bleeding. The anisotropy in the direction of casting and the heterogeneity relative to the depth were examined as the variation on 150-mm cube specimens and 150- by 150- by 450-mm columns, respectively. For the former, the tensile anisotropies were determined by the splitting test changing the loading direction. For the latter, splitting tensile strengths, unit weights, coefficients of water absorption and coarse aggregate contents of both the top and the bottom portions were determined and compared relative to the depth. There is no great difference in the resistance to segrega-tion during placing and the effects of segregation on the homogeneity after hardening between the concrete containing the admixture and the conventional air entrained concrete without the admixture when slump, water-cement ratio and fine aggregate percentage are held constant. Excessive dosage of the high-range water-reducing admixture tends to promote segregation of fresh concrete and subsequently tends to increase the heterogeneity of hardened concrete with the depth.
Click here to become an online Journal subscriber