Study of particle packing and paste rheology in alkali activated mixtures to meet the rheology demands of 3D Concrete Printing

Kondepudi, K. and Subramaniam, Kolluru V.L. and Nematollahi, B. and et al, . (2022) Study of particle packing and paste rheology in alkali activated mixtures to meet the rheology demands of 3D Concrete Printing. Cement and Concrete Composites, 131. pp. 1-12. ISSN 0958-9465

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Abstract

The rheological behavior of concrete mixtures made with alkali-activated fly ash-slag (AAFS) binder paste is investigated for varying aggregate content. The static yield stress, plastic viscosity and thixotropy of the mixtures are evaluated and related with the performance in 3D Concrete Printing (3DCP). The thixotropy of the concrete mixture is primarily influenced by AAFS binder paste composition and does not change with the aggregate content. Rheology control of the AAFS binder paste is achieved using additives like nano-clay, which enhance the buildup of internal structure and provide thixotropy in the concrete mixtures. The paste content, the surface area of aggregate, and the packing of solids in a concrete mixture influence its yield stress. The static yield stress increases sensitively in relation to the proportion of the surface area of the solids to the paste volume content in the concrete mixture. The minimum requirement of the paste content from packing of solids in the mixture is given by the Fuller-Thompson curve. Excess paste content in proportion to the demand determined from the surface area of aggregate and packing of solids in the concrete mixture produces a decrease in the static yield stress. For producing AAFS concrete mixtures suitable for 3DCP, the paste content in the concrete mixture should meet the requirement of paste demand, which depends on the aggregate content and packing of solids. Â© 2022 Elsevier Ltd

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IITH Creators:

IITH Creators	ORCiD
Subramaniam, Kolluru V.L.	https://orcid.org/0000-0002-5995-0911

Item Type:

Article

Additional Information:

The first author acknowledges the support provided by IIT Hyderabad-Swinburne University of Technology Joint PhD Program. In addition, the authors acknowledge the support by the Australian Research Council Linkage Infrastructure Grant LE170100168, Discovery Project DP210101680, and Discovery Early Career Researcher Award DE180101587. Further, the authors at Swinburne University of Tech- nology acknowledge the Victoria-Jiangsu Program for Technology and Innovation R&D grant funded by the Victorian Department of Jobs, Precincts and Regions in Australia, and the Jiangsu Science and Tech- nology Department in China.

Uncontrolled Keywords:

3D concrete printing, Aggregate packing, Geopolymer, Paste content, Rheology, Surface area

Subjects:

Civil Engineering > Construction & Building Technology
Civil Engineering

Divisions:

Department of Civil Engineering

Depositing User:

. LibTrainee 2021

Date Deposited:

21 Jun 2022 04:41

Last Modified:

22 Jun 2022 08:51