Improving structural build-up of limestone-calcined clay-cement pastes by using inorganic additives

Improving structural build-up of limestone-calcined clay-cement pastes by using inorganic additives

Chen, Y. (TU Delft Materials and Environment)
Zhang, Y. (TU Delft Materials and Environment)
He, S. (TU Delft Materials and Environment)
Liang, X. (TU Delft Materials and Environment)
Schlangen, E. (TU Delft Materials and Environment)
Copuroglu, Oguzhan (TU Delft Materials and Environment)

2023

In 3D concrete printing, fast structuration is a prerequisite for ideal buildability. This paper aims to study the impact of inorganic additives, i.e., CaCl₂ and gypsum, on structural build-up and very early-age hydration of limestone-calcined clay-cement (LC3) pastes within the first 70–80 min. Results show that, increasing the dosage of CaCl₂ or gypsum can accelerate storage modulus G' and static yield stress evolution with time, as well as increase chemically bound water (H) content and total specific surface area (SSA_total). Furthermore, good correlations were found between G' and H content, as well as static yield stress and the ratio of free water content to SSA_total. The acceleration by CaCl₂ can be attributed to stimulating C₃S and C₃A hydration and promoting crystal formation, i.e., ettringite, portlandite, and Friedel's salt. Additionally, the increase in gypsum percentage led to a large amount of unreacted gypsum in the system, resulting in an increase in SSA_total.

3D concrete printing
CaCl
Gypsum
Limestone-calcined clay-cement
Rheology
Structural build-up
Very early-age hydration

http://resolver.tudelft.nl/uuid:4434dcaa-0121-4c96-976f-3f9f44e0708c

https://doi.org/10.1016/j.conbuildmat.2023.131959

0950-0618

Construction and Building Materials, 392

Institutional Repository

journal article

© 2023 Y. Chen, Y. Zhang, S. He, X. Liang, E. Schlangen, Oguzhan Copuroglu