United States Department of Transportation
i
Comparison of conventional and self-consolidating concrete for drilled shaft construction.
-
2015-04-01
[PDF-1.43 MB]
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Corporate Publisher:
-
Abstract:Many entities currently use self-consolidating concrete (SCC), especially for drilled shaft construction. This project investigated the use of SCC
and various test methods to assess the suitability of SCC in underwater placement conditions. Eight mixtures were prepared in the laboratory; the
fresh properties of slump-flow, J-ring, set time, and washout characteristics were measured. Hardened properties tested included compressive and
flexural strength, modulus of elasticity, and surface resistivity.
The fresh concrete results of SCC showed that SCC produced with a No. 8 crushed stone or No. 8 gravel is adequate in terms of workability and
strength with the use of a high range water reducer. The L-box test results were varied across all mixtures and the method was abandoned in favor
of the washout test. The washout test results showed that for SCC mixtures being placed in an underwater condition, the addition of a VMA
greatly enhances the resistance of said concrete to washout.
Compressive and flexural strengths showed that SCC will be adequate for nearly all structural concrete and drilled shaft applications. The
modulus of elasticity values for mixtures tested were slightly increased compared to traditional concrete values showing that the SCC mixtures are
particularly suited for drilled shaft construction.
Surface resistivity values were slightly depressed for laboratory mixtures at 28-days of age, but field cast SCC mixtures will incorporate, not only
additional SCMs but a greater proportion of SCMs, leading to increased resistivity values to meet the specification.
Field construction results showed that the mixture was resistant to washout, exhibited excellent workability properties, and had excellent strength
characteristics.
The authors recommend incorporating SCC into the standards and specifications for Departmental use. At a minimum, Sections VIII and IV
should be amended to include appropriate language allowing the use of said mixtures. The use of SCC in an underwater placement condition
should require the use of a viscosity modifier.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
