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The Effect Of Viscosity Modifier Agent On The Early Age Strength Of The Limestone And Calcined Clay-Based Sustainable And 3D Printable Cementitious Material

Chen, Y. (author), Yalçinkaya, Ç. (author), Copuroglu, Oguzhan (author), Schlangen, E. (author)

Recently, our group attempted to develop the ternary blended (Portland cement, calcined clay and limestone) cementitious material for 3D concrete printing (3DCP). Due to the elimination of formwork during the layer-by-layer casting process, the printed material should have favorable elastic properties and green strength at the fresh state. A...

conference paper 2019

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Feasibility of Using Low CO2 Concrete Alternatives in Extrusion-Based 3D Concrete Printing

Chen, Y. (author), Veer, F.A. (author), Copuroglu, Oguzhan (author), Schlangen, E. (author)

In conventional concrete, replacing high-volume (more than 45%) of ordinary Portland cement (OPC) by supplementary cementitious materials (SCMs) is not a novel CO2 reduction method, whereas rarely in 3D printable concrete. This study attempts to explore the feasibility of using SCMs in 3D printable concrete. Initially, the existing binder mixes,...

conference paper 2018

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Effect of curing methods during a long time gap between two printing sessions on the interlayer bonding of 3D printed cementitious materials

Chen, Y. (author), Chang, Z. (author), He, S. (author), Copuroglu, Oguzhan (author), Šavija, B. (author), Schlangen, E. (author)

A good bond between the layers of 3D printed cementitious materials is a prerequisite for having high structural rigidity for the printed elements. However, the influence of printing process on an interlayer bond is still not well understood. This study investigates the influence of curing methods (i.e., air curing, plastic film covering, wet...

journal article 2022

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Sustainable materials for 3D concrete printing

Bhattacherjee, Shantanu (author), Basavaraj, Anusha S. (author), Rahul, A. V. (author), Santhanam, Manu (author), Gettu, Ravindra (author), Schlangen, E. (author), Chen, Y. (author), Copuroglu, Oguzhan (author), Wang, Li (author)

This paper explores the sustainability aspects of binders used in concrete 3D concrete printing. Firstly, a prospective approach to conduct sustainability-assessment based on the life cycle of 3D printed structures is presented, which also highlights the importance of considering the functional requirements of the mixes used for 3D printing....

journal article 2021

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Experimental investigation of the short-term creep recovery of hardened cement paste at micrometre length scale

Gan, Y. (author), Vandamme, Matthieu (author), Chen, Y. (author), Schlangen, E. (author), van Breugel, K. (author), Šavija, B. (author)

This paper presents an experimental investigation on the short-term creep recovery of cement paste at micrometre length scale. Micro-cantilever beams were fabricated and tested with 8 different loading series using the nanoindenter. It is found that cement pastes show high recovery ratios (>80%) even subjected to very high stress levels....

journal article 2021

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A discrete lattice model for assessment of buildability performance of 3D-printed concrete

Chang, Z. (author), Xu, Y. (author), Chen, Y. (author), Gan, Y. (author), Schlangen, E. (author), Šavija, B. (author)

In this work, the lattice model is applied to study the printing process and quantify the buildability (i.e., the maximum height that can be printed) for 3D concrete printing (3DCP). The model simulates structural failure by incorporating an element birth technique, time-dependent stiffness and strength, printing velocity, non-uniform...

journal article 2021

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Bond of steel-mortar interface interfered by stray current

Chen, Zhipei (author), Koleva, D.A. (author), Schlangen, E. (author)

The focus of this work is to present test results on the bond of steel-mortar interface undergoing stray current. The bond strength, derived by pull-out tests, is correlated to the electrochemical response of the steel rebar and the properties of the mortar bulk matrix. The effects of curing regimes (in terms of duration of curing) and...

journal article 2021

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3D printing of calcined clay-limestone-based cementitious materials

Chen, Y. (author), He, S. (author), Zhang, Y. (author), Wan, Z. (author), Copuroglu, Oguzhan (author), Schlangen, E. (author)

This paper aims to investigate the influences of high Portland cement substitutions (>60 wt%) by low-grade calcined clay (CC) and limestone (LF) on 3D concrete printability, stiffness evolution and early-age hydration. Results show that, with the same dosage of admixtures (superplasticizer and viscosity modifier), increasing LF and CC...

journal article 2021

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Predicting early-age stress evolution in restrained concrete by thermo-chemo-mechanical model and active ensemble learning

Liang, M. (author), Chang, Z. (author), He, S. (author), Chen, Y. (author), Gan, Y. (author), Schlangen, E. (author), Šavija, B. (author)

Early-age stress (EAS) is an important index for evaluating the early-age cracking risk of concrete. This paper encompasses a thermo-chemo-mechanical (TCM) model and active ensemble learning (AEL) for predicting the EAS evolution. The TCM model provides the data for the AEL model. First, based on Fourier's law, Arrhenius’ equation, and rate...

journal article 2022

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An approach to develop set-on-demand 3D printable limestone-calcined clay-based cementitious materials using calcium nitrate

Chen, Y. (author), Rahmani, Hossein (author), Schlangen, E. (author), Copuroglu, Oguzhan (author)

The implementation of extrusion-based 3D concrete printing (3DCP) in large-scale constructions is currently limited by concerns regarding rheology control and the sustainability of this process. To address these issues, this study presents an approach to develop limestone-calcined clay-based cementitious (LC3) materials accelerated by Ca(NO...

journal article 2023

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ASR: Insights into the cracking process via lattice fracture simulation at mesoscale based on the chemical reactions at microscale

Qiu, Xiujiao (author), Chang, Z. (author), Chen, J. (author), Schlangen, E. (author), Ye, G. (author), Schutter, Geert De (author)

In our former paper, based on a published 3D reactive transport model at microscale with the capability of simulating the chemical reactions involved in ASR, the location of expansive ASR gel related to the reactivity of aggregate, temperature, aggregate porosity and silica content in aggregate, is clarified. Based on the simulation results,...

journal article 2023

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Characterization of air-void systems in 3D printed cementitious materials using optical image scanning and X-ray computed tomography

Chen, Y. (author), Copuroglu, Oguzhan (author), Romero Rodriguez, C. (author), França de Mendonça Filho, F. (author), Schlangen, E. (author)

For many 3D printed cementitious materials, air voids may play a dominant role in the interlayer bond strength. However, to date, far too little attention has been paid to reveal the air void characteristics in 3D printed cementitious materials. Therefore, to fill this gap, this study attempts to provide an example of systematically...

journal article 2021

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Effect of coarse aggregate size on non-uniform stress/strain and drying-induced microcracking in concrete

Gao, Peng (author), Chen, Yang (author), Huang, Haoliang (author), Qian, Zhiwei (author), Schlangen, E. (author), Wei, Jiangxiong (author), Yu, Qijun (author)

Non-uniform stresses, strains and microcracking of the concretes with three coarse aggregate sizes (5–10 mm, 10–16 mm, 16–20 mm) dried under 40% relative humidity (RH) for 60 days were quantified using digital image correlation and lattice fracture modelling. The influencing mechanism of coarse aggregate size on the drying-induced...

journal article 2021

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Distribution of porosity surrounding a microfiber in cement paste

He, S. (author), Chen, Y. (author), Liang, M. (author), Yang, En-Hua (author), Schlangen, E. (author)

This study investigates the microstructural changes of cement paste due to the inclusion of polymeric microfiber at different water-to-cement (w/c) ratios. A procedure to quantify the porosity of epoxy impregnated interfacial transition zone (ITZ) is also presented. Results show that the microstructures of the ITZ beneath and above a...

journal article 2023

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

Chen, Y. (author), Zhang, Y. (author), He, S. (author), Liang, X. (author), Schlangen, E. (author), Copuroglu, Oguzhan (author)

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...

journal article 2023

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On the chemo-mechanical evolution process of high-volume slag cement paste

Liang, M. (author), Zhang, Y. (author), He, S. (author), Chen, Y. (author), Schlangen, E. (author), Šavija, B. (author)

This study investigated the evolution process of high-volume slag cement (HVSC) paste from a chemo-mechanical standpoint. HVSC specimens with a 70 w.t. % slag replacement rate were studied at various ages. Evolution of phase assemblage, microstructure development, and micromechanical properties were analyzed using TGA/XRD/MIP/SEM-EDS and nano...

journal article 2023

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A review of methods on buildability quantification of extrusion-based 3D concrete printing: From analytical modelling to numerical simulation

Chang, Z. (author), Chen, Y. (author), Schlangen, E. (author), Šavija, B. (author)

Herein, different kinds of methods for buildability quantification of 3D concrete printing are reviewed, including experimental approaches, analytical modelling, and numerical simulations. A brief introduction on printing process is first given. This discusses the material properties in different stages. Material printability, which...

journal article 2023

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Microstructural characterization of crack-healing enabled by bacteria-embedded polylactic acid (PLA) capsules

He, S. (author), Wan, Z. (author), Chen, Y. (author), Jonkers, H.M. (author), Schlangen, E. (author)

The current study investigates short-term and long-term crack-healing behaviour of mortars embedded with bacteria-based poly-lactic acid (PLA) capsules under both ideal and realistic environmental conditions. Two sets of specimens were prepared and subjected to different healing regimes, with the first set kept in a mist room for varying...

journal article 2023

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Does early age creep influence buildability of 3D printed concrete? Insights from numerical simulations

Chang, Z. (author), Liang, M. (author), Chen, Y. (author), Schlangen, E. (author), Šavija, B. (author)

Cementitious materials may exhibit significant creep at very early age. This is potentially important for concrete 3D printing, where the material is progressively loaded even before it sets. However, does creep actually affect the buildability of 3D printed concrete? Herein, the influence of early-age creep on the buildability of 3D printed...

journal article 2023

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Improving printability of limestone-calcined clay-based cementitious materials by using viscosity-modifying admixture

Chen, Y. (author), Chaves Figueiredo, S. (author), Li, Z. (author), Chang, Z. (author), Jansen, K. (author), Copuroglu, Oguzhan (author), Schlangen, E. (author)

In 3D concrete printing (3DCP), it is necessary to meet contradicting rheological requirements: high fluidity during pumping and extrusion, and high stability and viscosity at rest to build the layered structure. In this paper, the impact of the hydroxypropyl methylcellulose (HPMC)-based viscosity-modifying admixture (VMA) on the 3D printability...

journal article 2020