Mechanical properties, durability performance and interlayer adhesion of 3DPC mixtures: A state‐of‐the‐art review

Abstract

In this study, the strength and durability performance of 3D printing concrete mixtures (3DPC) were examined in terms of the materials used in their production and printing process parameters (interlayer interval time, printing speed, and nozzle shape). Due to the anisotropic nature of 3DPC, it was understood that the compressive strength depends on the loading direction. It was emphasized that it is necessary to control the shrinkage behavior of 3DPC mixtures due to the lack of formwork and the high dosage of binders. It was reported that the interlayer adhesion of 3DPC is highly dependent on the interlayer interval time and printing speed parameters. It was understood that nozzle shape and standoff distance affect the mechanical properties and surface roughness of 3DPC specimens, and this effect is more pronounced in mixtures with high static yield stress values.

Effect of nano-TiO2 size and utilization ratio on the performance of photocatalytic concretes; self-cleaning, fresh, and hardened state properties

“…As a result of the addition of 1.5% of NT with 28- and 38-nm particle sizes to the mixture, it was understood that the need for HRWRA in PSCM mixtures increased by 29% and 14%, respectively. It is thought that the need for HRWRA is higher due to the increase in the wettable surface area (Durgun et al 2022 ; Mardani-Aghabaglou et al 2018 ; Özen et al 2021 ; Şahin et al 2022 , 2020 ; Şahin and Mardani 2023b ) and the amount of adsorbed water due to the increased surface area due to the decrease in NT particle size (Kuo et al 2006 ). It was reported by Chen et al ( 2012 ) that the rapid hardening potential, which is directly dependent on the NT particle size and utilization ratio, directly affects the consistency retention capacity of the mixtures.…”

Effect of Silica Fume Utilization on Structural Build-Up, Mechanical and Dimensional Stability Performance of Fiber-Reinforced 3D Printable Concrete

“…Serious requirements, especially regarding the rheology of 3DPC, have been noted [ 11 ]. While fresh concrete should have relatively lower yield stress and viscosity values during the pumping and extrusion process, it was reported that after extrusion it should have a higher yield stress, viscosity value and an optimum structural build-up rate in order to resist parameters that may cause possible deformation [ 10 , 12 ]. Şahin and Mardani [ 9 ] reported that the parameters that can create deformation mentioned are as follows: (i) own weight, (ii) weight of the upper layers, and (iii) high extrusion pressure, respectively.…”

“…In studies conducted in the literature, it can be seen that both the thixotropic properties and strength properties of 3DPC mixtures can be positively affected by the addition of these agents [ 12 ]. SF and hydroxypropyl methylcellulose were proven to be effective viscosity modifying materials that positively affect the buildability and thixotropic behavior of 3DPC mixtures [ 26 ].…”

Use of recycled mortar as fine aggregates in pavement concrete applications

“…Earlier studies showed that the quality of the attached mortar is improved when the recycled aggregates are derived from enhanced performance parent concrete possessing relatively higher strengths [ 19 , 21 , 22 ]. The concrete mechanical properties may be improved by reducing the water-to-binder ratio (w/b) [ [23] , [24] , [25] , [26] ]. For mixing, several authors recommended pre-saturating the recycled aggregate fraction in order to reduce the exchange of moisture inside the concrete [ 15 , 18 , 26 , 27 ].…”