https://pureadmin.qub.ac.uk/ws/files/202071352/20200310_Paper_on_Physics_in_DFC_revised_1_.pdf

Extrusion-based additive manufacturing with cement-based materials – Production steps, processes, and their underlying physics: A review

This paper provides a comprehensive review of the material behaviour for extrusion-based concrete 3D printing spanning from the early age to long-term performance. We begin with a discussion on the recent progress on the understanding of early-age behaviour. Following this, the mechanical response in the hardened state, and the different strategies to introduce reinforcement are reviewed. Finally, we present insights and perspectives on the transport mechanisms in printed concrete to assess the long-term performance, and also discuss the overall impact of construction by concrete 3D printing on sustainability.

Extrusion-based concrete 3D printing from a material perspective : a state-of-the-art review

Development of 3D-printable ultra-high performance fiber-reinforced concrete for digital construction

On the emergence of 3D printable Engineered, Strain Hardening Cementitious Composites (ECC/SHCC)

https://par.nsf.gov/servlets/purl/10166329

3-D printing of concrete: Beyond horizons

Development of 3D printable engineered cementitious composites with ultra-high tensile ductility for digital construction

This study investigated 3D concrete printing of permanent formwork for concrete column construction. The effect of different hydroxypropyl methyl cellulose (HPMC) contents (0, 0.0003 and 0.0006 by mass of binder) and the water-to-binder (W/B) ratios (0.27, 0.29 and 0.31) on the rheological properties, structural build-up and mechanical performance were studied using several mixtures for manufacture of the permanent formworks. The results showed that the mixture with the HPMC = 0.0006 and the W/B = 0.27 showed the maximum static yield stress, largest thixotropy and maximum green strength, and thereby selected as the optimum mixture. The plastic failure of the optimum mixture was also predicted using a thixotropy model and was compared with the experimental results. Subsequently, three concrete columns with different longitudinal steel reinforcement ratios (0.0%, 1.9% and 2.5%) were constructed using the printed concrete as the permanent formwork and tested in compression. Good bonding was observed at the interface of the cast-in-place concrete and the printed concrete permanent formwork. In addition, it was observed that the initial stiffness, the maximum bearing capacity and the corresponding longitudinal displacement of the concrete columns increased, as the longitudinal reinforcement ratio increased. The counterpart concrete columns using the conventional formworks were also constructed and tested for comparison. In comparison, the concrete columns made using the printed concrete as the permanent formwork obtained a higher stiffness and bearing capacity than the counterpart conventional concrete columns. The reasons for the differences are explained.

3D concrete printing of permanent formwork for concrete column construction

Seismic performance and resilience assessment of friction damped self-centering prestressed concrete frames

Mechanical properties of engineered cementitious composites beams fabricated by extrusion-based 3D printing

In recent years, the occurrence of a series of extreme events has raised awareness of what progressive collapse of mainstream reinforced concrete frame structures can cause in terms of damage and direct/indirect losses. Even though these low-probability/high-consequence events, which are triggered by accidental loads not necessarily considered at the design stage, have attracted growing attention, less consideration has been given to spatial effects caused by floor slabs and infill walls in the progressive collapse simulation of RC frame structures. A large number of research studies have proposed multifarious methods, the correctness and simplicity of which are characterized by different levels that are theory- and/or method-specific. Therefore, in order to assess and quantify the influence of floor slabs and infill walls on progressive collapse resistance of 3D RC frame structures, an efficient numerical modeling approach was first developed using OpenSees software. Then, the modeling strategy was validated by simulating different experimental test results. The numerical investigation was further expanded by performing incremental dynamic analysis on both 2D and 3D structural models. The results show that secondary and/or non-structural components such as floor slabs and infill walls produce a significant improvement in the capacity of the structure to resist progressive collapse, and that the respective characteristics of the two are magnified due to the coupling effect in the space frame. 

Zhenxin Zhou

Papers

Development of 3D printable engineered cementitious composites with ultra-high tensile ductility for digital construction

3D concrete printing of permanent formwork for concrete column construction

Seismic performance and resilience assessment of friction damped self-centering prestressed concrete frames

Mechanical properties of engineered cementitious composites beams fabricated by extrusion-based 3D printing

Investigation of 3D effects on dynamic progressive collapse resistance of RC structures considering slabs and infill walls