Project Title

Influence of Casting Conditions on Durability and Structural Performance of HPC-AR: Optimization of Self-Consolidating Concrete to Guarantee Homogeneity during Casting of Long Structural Elements

University

Missouri University of Science and Technology

Principal Investigator

Dimitri Feys
Missouri University of Science and Technology

PI Contact Information

feysd@mst.edu; 573-341-7193

Funding Source(s) and Amounts Provided (by each agency or organization)

Coreslab Structures (In-Kind): $60,307
RE-CAST: $60,307

Total Project Cost

$120,614

Matching Agency ID or Contract Number

Coreslab Structures: In-Kind Support
RE-CAST: Account # 0050028

RE-CAST Grant Award Number

DTRT13-G-UTC45

Start and End Dates

Start Date: January 1, 2015
End Date: May 15, 2017

Brief Description of Research Project

The main objective of this project is to extend the understanding of dynamic segregation of self-consolidating concrete. Dynamic segregation is the separation of coarse aggregates from the mortar during flow, which can negatively affect the performance of concrete. By means of a modified version of the tilting box test, the dynamic segregation of SCC can be monitored over different cycles at different cycle times. A workability box for good stability has been proposed in literature. The proposed project aims to extend this workability box principle for different flow distances (number of cycles) and different concrete compositions. From previous studies, the paste volume (or mortar volume) in concrete appeared a critical factor.

The laboratory research will be continued in an industrial setting. The testing parameters in the tilting box (number of cycles and duration of cycles) will be coupled to the flow distance and flow velocity in real formworks. Furthermore, the dynamic segregation index will be related to a reduction in concrete performance, in terms of mechanical properties and durability of the concrete, and bond strength with the rebars or prestress strands.

Based on the outcome of the research, performance specifications, in terms of fresh concrete properties, will be developed and the robustness to small variations in constituent elements of a typical, well-performing SCC mixture will be investigated.

Describe Implementation of Research Outcomes

The Missouri DOT is interested in the research project and has shown the intention to use the performance specifications for infrastructure elements made with SCC. In collaboration with Coreslab Structures, the suggested specifications can be communicated to other agencies, enhancing further implementation.

Impacts/Benefits of Implementation

Coupling dynamic segregation to a reduction in performance is a new step in making concrete infrastructures more durable and sustainable. This will be achieved by the developed performance specifications on fresh SCC properties.

Web Links

Final Report: PDF

Project website: http://recast.mst.edu/projects/influenceofcastingconditionsonperformance/