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.
American Concrete Institute
38800 Country Club Dr.
Farmington Hills, MI
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: Paste Microhardness-Promising Technique for Estimating Water-Cement Ratio
Author(s): B. Erlin and R. A. Campbell
Publication: Special Publication
Appears on pages(s): 43-56
Keywords: admixtures; blast-furnace slag; microhardness; water-cement ratio
Abstract:The Knoop microhardness method (ASTM 384) and the Rockwell microhardness method (ASTM E 18)-each show promise for estimating water-cement ratios of hardened paste. Tests of hardened pastes at water-cement ratios from 0.30 to 0.55 were completed. A good relationship of Knoop or Rockwell microhardness to water-cement ratio exists. The Rockwell microhardness method was done using automated image analysis equipment and was much faster. Further evaluations need to be done as follows: (1) the effect of indentation size, which can be controlled by varying the load weight; (2) rate of loading effect; (3) effects of inert and chemically active admixtures (e.g. limestone, ground granulated blast-furnace slag, pozzolans); (4) the effect of the degree of cement hydration; (5) effects of carbonation; (6) magnitude of spurious data resulting because of subsurface materials (e.g. residual cement, aggregate fines); and (7) effects of different surface preparation techniques. The microhardness method has promise as a means for estimating water-cement ratio of hardened concrete paste. It is hoped that the work completed to date will be continued by others.
Click here to become an online Journal subscriber