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The use of additive manufacturing in self-healing cementitious materials: A state-of-the-art review

Wan, Z. (author), Xu, Y. (author), He, S. (author), Schlangen, E. (author), Šavija, B. (author)

This paper presents a state-of-the-art review on the application of additive manufacturing (AM) in self-healing cementitious materials. AM has been utilized in self-healing cementitious materials in three ways: (1) concrete with 3D-printed capsules/vasculatures; (2) 3D concrete printing (3DCP) with fibers or supplementary cementitious...

journal article 2024

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Autogenous deformation-induced stress evolution in cementitious materials considering viscoelastic properties: A review of experiments and models

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

Early-age cracking risk induced by autogenous deformation is high for cementitious materials of low water-binder ratios. The autogenous deformation, viscoelastic properties, and stress evolution are three important factors for understanding and quantifying the early-age cracking risk. This paper systematically reviewed the experimental and...

review 2024

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Structural performance of reinforced concrete beams with self-healing cover zone

He, S. (author), Lukovic, M. (author), Jonkers, H.M. (author), Schlangen, E. (author)

In the current study, experiments were carried out to investigate the structural performance of reinforced concrete (RC) beams with a self-healing cover zone. The cover zone consists of a 1.5-cm-thick layer of bacteria-embedded strain hardening cementitious composite (SHCC) for a combination of crack width control and crack healing. The aim is...

conference paper 2023

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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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Ultra-thin Strain Hardening Cementitious Composite (SHCC) layer in reinforced concrete cover zone for crack width control

He, S. (author), Mustafa, S. (author), Chang, Z. (author), Liang, M. (author), Schlangen, E. (author), Lukovic, M. (author)

In the current study, experiments and numerical simulations were carried out to investigate the cracking behavior of reinforced concrete beams consisting of a very thin layer (i.e., 1 cm in thickness) of SHCC in the concrete cover, tension zone. A novel type of SHCC/concrete interface that features a weakened chemical adhesion but an enhanced...

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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An enhanced lattice beam element model for the numerical simulation of rate-dependent self-healing in cementitious materials

Sayadi, Sina (author), Chang, Z. (author), He, S. (author), Schlangen, E. (author), Mihai, I.C. (author), Jefferson, Anthony (author)

This paper describes the development of a discrete lattice model for simulating structures formed from self-healing cementitious materials. In particular, a new approach is presented for simulating time dependent mechanical healing in lattice elements. The proposed formulation is designed to simulate the transient damage and healing behaviour...

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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Strain Hardening Cementitious Composite in Reinforced Concrete Cover Zone for Crack Width Control

He, S. (author), Lukovic, M. (author), Schlangen, E. (author)

In the current study, experiments were carried out to investigate the cracking behaviour of reinforced concrete beams consisting of 1-cm-thick layer of Strain Hardening Cementitious Composite (SHCC) in the concrete cover zone. The hybrid SHCC/concrete beams with different types of interfaces were tested and compared with control reinforced...

conference paper 2023

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Effect of matrix self-healing on the bond-slip behavior of micro steel fibers in ultra-high-performance concrete

Al-Obaidi, S.M.J. (author), He, S. (author), Schlangen, E. (author), Ferrara, Liberato (author)

This study investigates the bond-slip behavior of micro steel fibers embedded into an Ultra-High-Performance Concrete (UHPC) matrix as affected by the self-healing of the same matrix in different exposure conditions. The UHPC matrix contains a crystalline admixture as a promoter of the autogenous self-healing specially added to enhance the...

journal article 2023

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Predicting micromechanical properties of cement paste from backscattered electron (BSE) images by computer vision

Liang, M. (author), He, S. (author), Gan, Yidong (author), Zhang, Hongzhi (author), Chang, Z. (author), Schlangen, E. (author), Šavija, B. (author)

This paper employs computer vision techniques to predict the micromechanical properties (i.e., elastic modulus and hardness) of cement paste based on an input of Backscattered Electron (BSE) images. A dataset comprising 40,000 nanoindentation tests and 40,000 BSE micrographs was built by express nanoindentation test and Scanning Electron...

journal article 2023

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Lattice modelling of early-age creep of 3D printed segments with the consideration of stress history

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

We propose a new numerical method to analyze the early-age creep of 3D printed segments with the consideration of stress history. The integral creep strain evaluation formula is first expressed in a summation form using superposition principle. The experimentally derived creep compliance surface is then employed to calculate the creep strain...

journal article 2023

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Autogenous deformation induced- stress evolution in high-volume GGBFS concrete: Macro-scale behavior and micro-scale origin

Liang, M. (author), Chang, Z. (author), Zhang, Y. (author), Cheng, H. (author), He, S. (author), Schlangen, E. (author), Šavija, B. (author)

This study aims to experimentally investigate the autogenous deformation and the stress evolution in restrained high-volume ground granulated blast furnace slag (GGBFS) concrete. The Temperature Stress Testing Machine (TSTM) and Autogenous Deformation Testing Machine (ADTM) were used to study the macro-scale autogenous deformation and stress...

journal article 2023

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Rheology control of limestone calcined clay cement pastes by modifying the content of fine-grained metakaolin

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

Limestone-calcined clay-cement (LC3), as one of the most promising sustainable cements, has been under development over the past decade. However, many uncertainties remain regarding its rheological behaviors, such as the metakaolin content of calcined clay. This study aims to investigate the effect of increasing the content of fine-grained...

journal article 2023

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A New Method to Quantitatively Characterize the Porosity of Fiber/Matrix Interfacial Transition Zone (ITZ) via Longitudinal Cross-Sections

He, S. (author), Liang, M. (author), Yang, En-hua (author), Schlangen, E. (author)

The properties of the interfacial transition zone (ITZ) between microfiber and cement-based matrix are of primary significance for the overall behavior of strain hardening cementitious composites (SHCCs). However, due to the relatively small diameter of polymeric microfibers (e.g., PVA fiber), it is technically difficult to obtain...

book chapter 2023

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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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Stress evolution in restrained GGBFS concrete due to autogenous deformation: bayesian optimization of aging creep

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

Stress evolution of restrained concrete is a significant direct index in early-age cracking (EAC) analysis of concrete. This study presents experiments and numerical modelling of the early-age stress evolution of Ground granulated blast furnace slag (GGBFS) concrete, considering the development of autogenous deformation and creep. Temperature...

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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Effects of bacteria-embedded polylactic acid (PLA) capsules on fracture properties of strain hardening cementitious composite (SHCC)

He, S. (author), Zhang, Shizhe (author), Lukovic, M. (author), Schlangen, E. (author)

Strain hardening cementitious composite (SHCC) is a special class of ultra-ductile material which has autogenous self-healing capability due to its intrinsic tight crack widths. To further improve its healing ability, healing agent (HA) can be incorporated in SHCC, enabling it also the autonomous self-healing mechanism. In this study, the...

journal article 2022