Rheological, Microstructural Characterization and Interlayer Bonding of 3d Printed Cement Mortars with Slump−Retaining Polycarboxylate Superplasticizer

Purpose This study aims to focus on the effect of interlayer bonding and thermal decomposition on the mechanical properties of fused filament fabrication-printed polylactic acid specimens at high extrusion temperatures. Design/methodology/approach A printing process, that is simultaneous manufacturing of contour and specimen, is used to improve the printing accuracy at high extrusion temperatures. The effects of the extrusion temperature on the mechanical properties of the interlayer and intra-layer are evaluated via tensile experiments. In addition, the microstructure evolution affected by the extrusion temperature is observed using scanning electron microscopy. Findings The results show that the extrusion temperature can effectively improve the interlayer bonding property; however, the mechanical properties of the specimen for extrusion temperatures higher than 270°C may worsen owing to the thermal decomposition of the polylactic acid (PLA) material. The optimum extrusion temperature of PLA material in the three-dimensional (3D) printing process is recommended to be 250–270°C. Originality/value A temperature-compensated constitutive model for 3D printed PLA material under different extrusion temperatures is proposed. The present work facilitates the prediction of the mechanical properties of specimens at an extrusion temperature for different printing temperatures and different layers.

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Mechanical and microstructural characterization of cement mortars prepared by waste foundry sand (WFS)

Journal of the Australian Ceramic Society ◽

10.1007/s41779-017-0096-9 ◽

2017 ◽

Vol 53 (2) ◽

pp. 829-837 ◽

Cited By ~ 5

Author(s):

Sinem Çevik ◽

Tugba Mutuk ◽

Başak Mesci Oktay ◽

Arife Kübra Demirbaş

Keyword(s):

Microstructural Characterization ◽

Foundry Sand ◽

Cement Mortars ◽

Waste Foundry Sand

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Effect of Structural Build-Up on Interlayer Bond Strength of 3D Printed Cement Mortars

Materials ◽

10.3390/ma14020236 ◽

2021 ◽

Vol 14 (2) ◽

pp. 236

Author(s):

Tinghong Pan ◽

Yaqing Jiang ◽

Hui He ◽

Yu Wang ◽

Kangting Yin

Keyword(s):

Bond Strength ◽

Surface Moisture ◽

Cement Mortars ◽

Nano Clay ◽

3D Printed ◽

Time Gap ◽

The Relationship ◽

Insight Into ◽

Interlayer Bond ◽

Operational Time

Understanding the relationship between the intrinsic characteristics of materials (such as rheological properties and structural build-up) and printability and controlling intrinsic characteristics of materials through additives to achieve excellent printability is vital in digital concrete additive manufacturing. This paper aims at studying the effects of material’s structural build-up on the interlayer bond strength of 3DPC with different time gaps. Structural build-up can indirectly affect the interlayer bond strength by affecting the surface moisture of concrete. Based on the structural build-up of 3DPC, a new parameter, maximum operational time (MOT), is proposed, which can be considered as the limit of time gap to ensure high interlayer bond strength. Slump-retaining polycarboxylate superplasticizer (TS) slightly slows down the physical flocculation rate, but increases the maximum operational time of the cement paste. Nano clay significantly increases the sort-term structural build-up rate and has the function of internal curing and water retaining. Composite with nano-clay and TS can reduce the loss of surface moisture of 3D printed layers, prevent the formation of interface weak layer, and increase the interlayer bond strength between printed layers. This contribution can provide new insight into the design of 3D-printed ink with good extrudability, outstanding buildability, and excellent interlayer bond strength.

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Microstructural Characterization of 3D Printed Cementitious Materials

Materials ◽

10.3390/ma12182993 ◽

2019 ◽

Vol 12 (18) ◽

pp. 2993 ◽

Cited By ~ 14

Author(s):

Jolien Van Der Putten ◽

Maxim Deprez ◽

Veerle Cnudde ◽

Geert De Schutter ◽

Kim Van Tittelboom

Keyword(s):

Process Parameters ◽

Mechanical Performance ◽

Three Dimensional ◽

Microstructural Characterization ◽

Lower Surface ◽

Cementitious Materials ◽

Lower Amount ◽

Time Interval ◽

3D Printed ◽

Printing Speed

Three-dimensional concrete printing (3DCP) has progressed rapidly in recent years. With the aim to realize both buildings and civil works without using any molding, not only has the need for reliable mechanical properties of printed concrete grown, but also the need for more durable and environmentally friendly materials. As a consequence of super positioning cementitious layers, voids are created which can negatively affect durability. This paper presents the results of an experimental study on the relationship between 3DCP process parameters and the formed microstructure. The effect of two different process parameters (printing speed and inter-layer time) on the microstructure was established for fresh and hardened states, and the results were correlated with mechanical performance. In the case of a higher printing speed, a lower surface roughness was created due to the higher kinetic energy of the sand particles and the higher force applied. Microstructural investigations revealed that the amount of unhydrated cement particles was higher in the case of a lower inter-layer interval (i.e., 10 min). This phenomenon could be related to the higher water demand of the printed layer in order to rebuild the early Calcium-Silicate-Hydrate (CSH) bridges and the lower amount of water available for further hydration. The number of pores and the pore distribution were also more pronounced in the case of lower time intervals. Increasing the inter-layer time interval or the printing speed both lowered the mechanical performance of the printed specimens. This study emphasizes that individual process parameters will affect not only the structural behavior of the material, but they will also affect the durability and consequently the resistance against aggressive chemical substances.

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Impregnation and interlayer bonding behaviours of 3D-printed continuous carbon-fiber-reinforced poly-ether-ether-ketone composites

Composites Part A Applied Science and Manufacturing ◽

10.1016/j.compositesa.2019.03.020 ◽

2019 ◽

Vol 121 ◽

pp. 130-138 ◽

Cited By ~ 14

Author(s):

Meng Luo ◽

Xiaoyong Tian ◽

Junfan Shang ◽

Weijun Zhu ◽

Dichen Li ◽

...

Keyword(s):

Carbon Fiber ◽

Fiber Reinforced ◽

Ether Ether Ketone ◽

Poly Ether Ether Ketone ◽

Continuous Carbon Fiber ◽

3D Printed ◽

Ether Ketone ◽

Carbon Fiber Reinforced ◽

Interlayer Bonding

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Interlayer Bonding Strength of 3D Printed PEEK Specimens

Soft Matter ◽

10.1039/d1sm00417d ◽

2021 ◽

Author(s):

Chya-Yan Liaw ◽

John W Tolbert ◽

Lesley W Chow ◽

Murat Guvendiren

Keyword(s):

3D Printing ◽

High Performance ◽

Important Group ◽

High Performance Polymers ◽

High Performance Polymer ◽

Ether Ether Ketone ◽

Poly Ether Ether Ketone ◽

3D Printed ◽

Ether Ketone ◽

Interlayer Bonding

Recent advances in extrusion-based filament 3D printing technology enable the processability of high-performance polymers. Poly(ether ether ketone) (PEEK) is an important group of high-performance polymer that has been widely used...

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