Doctoral Dissertations

Abstract

"Robustness, which is defined as the capacity of a mixture to tolerate small variations in constituent elements, mixing parameters or temperature that are inevitable with production at any significant scale, is a key property to expand the practical implementation of self-consolidating concrete (SCC). At the first step, the effect of different amount of water, amount of superplastizer, mixing time, mixing speed and the addition time of superplastizer on the rheological properties of cement pastes with SCC consistency, has been evaluated. Two different SCC mix design concepts, the powder-type and VMA-type were selected for this research. The results show that the selected powder-type mix design is more robust than the VMA-type to a change in addition time of SP. Then, an experimental study was conducted to evaluate different mix design parameters by varying the binder combination, the type of PCE-SP and the addition of viscosity-modifying agent (VMA) to determine which particular parameters cause the largest difference in rheological behavior due to a variation in adding time of SP. In third step, the robustness of the "loss of workability" of flowable cement pastes, which is mainly affected by variations in the water content and the adding time of the superplasticizer, was evaluated. A comparison study was performed to develop a more accurate vision on robustness of cement paste, and also concrete, by taking into account the time-dependency of the rheological properties. Furthermore, the change in rheological properties of well-dispersed cement pastes subjected to different maximum shear rates has been conducted. It was shown that the choice of maximum shear rate during the rheological measurements is critical for the values of the rheological properties"--Abstract, page iv.

Advisor(s)

Feys, Dimitri

Committee Member(s)

Kumar, Aditya
Mendoza, Cesar
Schuman, Thomas P.
Smith, Jeffrey D.

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

Ph. D. in Civil Engineering

Sponsor(s)

Missouri. Department of Transportation
Missouri University of Science and Technology. RE-CAST Tier-1 University Transportation Center
Missouri University of Science and Technology. National University Transportation Center
Fonds voor Wetenschappelijk Onderzoek--Vlaanderen

Comments

The authors would like to acknowledge the National University Transportation Center at the Missouri University of Science and Technology (project R333), the Science Foundation in Flanders (FWO), RE-CAST Tier 1 University Transportation Center (US DOT) at the Missouri University of Science and Technology (grant DTRT13-G-UTC45) and the center for infrastructure engineering studies (CIES) at Missouri S&T for the financial support of this project.

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2018

Journal article titles appearing in thesis/dissertation

  • Which parameters, other than the water content, influence the robustness of cement paste with SCC consistency?
  • Mix design factors affecting the magnitude of variations in rheological properties of self-consolidating cement paste induced by the addition time of PCE-superplasticizer
  • Time evalution of rheology of cement pastes affected by mix design and mixing procedure
  • Influence of maximum applied shear rate on the rheological properties of flowable cement pastes

Pagination

xvii, 201 pages

Note about bibliography

Includes bibliographic references.

Rights

© 2018 Azadehalsadat Asghari, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 11413

Electronic OCLC #

1084472309

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