Title:
Optimizing Crack Resistant Cement Paste for 3D Printing using Internal Curing and Shrinkage Mitigating Materials
Author(s):
Aghaee
Publication:
Web Session
Volume:
ws_S24_Aumit Paul.pdf
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
3/23/2024
Abstract:
3D printing concrete is vulnerable to shrinkage cracking for several reasons such as high content of cement, lack of proper curing, and direct exposure to the ambient environment. Use of expansive agent (EA), shrinkage reducing admixture (SRA), and super absorbent polymer (SAP) can effectively address the issue. However, the excessive use or inefficient combination of these materials impairs rheological and mechanical properties. This presentation elucidates the optimization of crack-resistant paste with adequate rheological and mechanical properties using the factorial design approach. A multi-objective optimization based on the static and dynamic yield stress, plastic and apparent viscosities, and thixotropy over time as well as compressive strength and shrinkage development are conducted to derive the models. It is shown that the use of EA combined with low contents of SAP or SRA facilitates the production of crack-resistant flowable and thixotropic cement paste with high pumpability and buildability, high strength, and no autogenous shrinkage applicable to 3D printing.