Fresh properties of a novel 3D printing concrete ink

Rheological and harden properties of the high-thixotropy 3D printing concrete

Additive manufacturing as an enabling technology for digital construction: A perspective on Construction 4.0

Large-scale 3D printing by a team of mobile robots

https://bura.brunel.ac.uk/bitstream/2438/16247/1/Fulltext.pdf

Additive manufacturing technology and its implementation in construction as an eco-innovative solution

Use of calcium sulfoaluminate cements for setting control of 3D-printing mortars

Numerical and experimental studies of aggregate blocking in mortar extrusion

Concrete 3D printing is an emerging technology in the construction sector, and it has been undergoing an exponential increase in that field. Nowadays, one of the most challenging subjects in 3D printing is the reinforcing method, particularly at the interface level between printed layers. These interfaces are considered the weakest parts in a printed element, and are the cause of its anisotropic behavior. Therefore, the study at hands first presents a customized 4-point bending test, developed particularly to evaluate the effectiveness of a newly developed inter-layer reinforcing technique. Second, it evaluates the effects and potentials of inserting steel nails or screws across successive layers. The type of reinforcement in terms of surface geometry, as well as the effect of the reinforcement’s number and arrangement over the printed surfaces was extensively assessed. Hence, it was found that inter-layer reinforcement is possible using local reinforcement. Notably, the results demonstrated that the surface geometry of the reinforcing agents greatly influences the quality of the bond generated with printed concrete layers. Precisely, reinforcements having smooth surfaces can be a real advantage to strengthen the interfaces between successive layers if properly distributed and implemented.

Inter-layer reinforcement of 3D printed concrete elements

Several types of industrial wastes can be used as raw materials to obtain calcium sulfoaluminate (CSA) cement clinker. The first aim of this work was to define the maximum content of zinc that coul...

Incorporation of zinc in calcium sulfoaluminate cement clinker

Printable mortars used in 3D printing of cementitious materials must have rheological behaviour and setting rigorously controlled. In this research, mixes made of two types of cement, ordinary Portland cement (OPC) and Calcium Sulfoaluminate cement (CSA) are adopted to control the printability of a mortar. Extrudability, buildability and comparable compressive strength to that of a traditional mortar are the specifications required by the printable mortar. Different mixes of OPC/CSA cement pastes (ranging between 0 and 10% of CSA) and 2 mixes of OPC/CSA mortars (0 and 7% of CSA) are studied. The cement pastes are studied by isothermal calorimetry and rheometer. Heat of hydration and cement pastes' yield stress increase with the dosage of CSA in the mix. A mortar made out of 7% CSA in previous article [1] is then tested in laboratory and their behaviour is compared to the results of the cement pastes.

Noura Khalil

Papers

Use of calcium sulfoaluminate cements for setting control of 3D-printing mortars

Numerical and experimental studies of aggregate blocking in mortar extrusion

Inter-layer reinforcement of 3D printed concrete elements

Incorporation of zinc in calcium sulfoaluminate cement clinker

Characterization of 3D Printing Mortars Made with OPC/CSA Mixes