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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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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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The Effect of Viscosity-Modifying Admixture on the Extrudability of Limestone and Calcined Clay-Based Cementitious Material for Extrusion-Based 3D Concrete Printing

Chen, Y. (author), Chaves Figueiredo, S. (author), Yalçinkaya, Ç. (author), Copuroglu, Oguzhan (author), Veer, F.A. (author), Schlangen, E. (author)

To investigate the effects of viscosity-modifying admixture (VMA) on the extrudability of limestone and calcined clay-based cementitious materials, three mix designs with different dosages of VMA were proposed in this study. The ram extrusion was utilized as an extrusion model for exploring the fresh properties of printable materials. Two...

journal article 2019

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Limestone and Calcined Clay-Based Sustainable Cementitious Materials for 3D Concrete Printing: A Fundamental Study of Extrudability and Early-Age Strength Development

Chen, Y. (author), Li, Z. (author), Chaves Figueiredo, S. (author), Copuroglu, Oguzhan (author), Veer, F.A. (author), Schlangen, E. (author)

The goal of this study is to investigate the effects of different grades of calcined clay on the extrudability and early-age strength development under ambient conditions. Four mix designs were proposed. Three of them contained high, medium, and low grades of calcined clay, respectively, and one was the reference without calcined clay. In terms...

journal article 2019

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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

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Effect of different grade levels of calcined clays on fresh and hardened properties of ternary-blended cementitious materials for 3D printing

Chen, Y. (author), Romero Rodriguez, C. (author), Li, Z. (author), Chen, B. (author), Copuroglu, Oguzhan (author), Schlangen, E. (author)

This study aims to investigate the influences of different grades of calcined clay on 3D printability, compressive strength (7 days), and hydration of limestone and calcined clay-based cementitious materials. Calcined clays that contained various amounts of metakaolin were achieved by blending low-grade calcined clay (LGCC) and high-grade...

journal article 2020

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Effect of printing parameters on interlayer bond strength of 3D printed limestone-calcined clay-based cementitious materials: An experimental and numerical study

Chen, Y. (author), Jansen, K. (author), Zhang, H. (author), Romero Rodriguez, C. (author), Gan, Y. (author), Copuroglu, Oguzhan (author), Schlangen, E. (author)

For a single batch material, time intervals and nozzle standoff distances between two subsequent layers are two critical printing parameters that influence the mechanical performance of the printed concrete. This paper presents an experimental and numerical study to investigate the impacts of these printing parameters on the interlayer bond...

journal article 2020

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Micro-cantilever testing on the short-term creep behaviour of cement paste at micro-scale

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

This study proposes an experimental method for studying the short-term creep behaviour of cement paste at micro-scale. The micro-bending tests on miniaturized cantilever beams were used to characterize the viscoelastic properties of cement paste. The effects of w/b ratio, the type of binder and the stress level on the microscopic creep...

journal article 2020

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Investigation of drying-induced non-uniform deformation, stress, and micro-crack propagation in concrete

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

Concrete generally deforms and cracks in a non-uniform manner under drying-induced stress. This study used the lattice fracture model to simulate the drying-induced non-uniform deformations, stresses, and micro-crack propagation in concrete. Experiments were designed to validate the lattice fracture model, wherein the drying-induced non...

journal article 2020

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Effect of relative humidity on drying-induced damage in concrete: A comparative study of digital image correlation and lattice modelling

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

To assess the effect of relative humidity (RH) on drying-induced damage in concrete, the non-uniform strains and microcracks in concrete under different RH conditions were obtained using the digital image correlation (DIC) technique and lattice fracture model. The simulated non-uniform displacements were consistent with those captured using...

journal article 2020

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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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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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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 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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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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A review of printing strategies, sustainable cementitious materials and characterization methods in the context of extrusion-based 3D concrete printing

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

This paper aims to provide a systematical review of the available printing strategies, sustainable cementitious materials and characterization methods for extrusion-based 3D concrete printing (3DCP). The printing strategies, consisting of printing setup, process, and material requirements, were summarized initially. In the material aspect,...

journal article 2022