Interlayer Bond Strength Research Articles

Thermal-responsive soil-hydrogel composite for additive construction

To improve the formability and bonding strength of 3D printing soil, a temperature-stimulating responsive intelligent soil-hydrogel 3D printing formula was innovatively developed by combining soil and gelatin. Varied soil-gelatin composites, featuring different gelatin content by weight of soil (0 %, 0.5 %, 1 %, and 1.5 %), were prepared and cured at 5 °C to facilitate the crosslinking of gelatin. An array of tests, including rheological assessments, compressive tests, and scanning electron microscopy analysis. Were conducted to thoroughly characterize the performance of gelatin-soil composites for 3D printing. Our findings unveiled that, following the cross-linking of gelatin at 5 °C, the gelatin-soil composites exhibited superior formability and bond strength compared to the reference. Furthermore, the soil-gelatin composites demonstrated not only comparable compressive strength to the reference but also enhanced interlayer bond strength. This innovative soil-hydrogel 3D printing formula, combining the versatility of soil and the responsive characteristics of gelatin, presents a promising avenue for advancing the capabilities of 3D printed soil.

Research progress on constructability of 3D printed concrete

Abstract 3D printing concrete technology is an innovative building technology for green manufacturing, but in order to achieve better performance requirements, there is still a need for continuous in-depth research on 3D printing parameters, theory and the use of admixtures. In this paper, the effects of three printing parameters, interlayer interval time, nozzle travel speed and height, and nozzle shape on the constructability of 3D printed concrete were discussed, and the effects of bonding properties on the constructability of 3D printed concrete were analyzed. The study found that shortening the interval time between layers, reducing the travel speed and height of the nozzle, and choosing a triangular nozzle can improve the interlayer bond strength of 3D printed concrete, and thus improve the constructability of 3D printed concrete.

Time-dependent behaviour of 3D printed fibre-reinforced limestone calcined clay cement concrete under sustained loadings

The evolution of 3D-printed concrete (3DPC) structures has made remarkable impacts in the construction industry and academia for prospective engineering practice globally. This is due to promising outcomes of various investigations on its construction coupled with several advantages it offers over conventional cast concrete. However, the time-dependent deformation of 3DPC under sustained loading is still unknown and requires extensive research. Quasi-static studies have also shown that creep could be of great concern due to its production technique involving layer stacking, which eventually leads to weak interlayer bond strength. This paper experimentally investigates the time-dependent behaviour of fibre-reinforced printed concrete (FRPC) containing limestone calcined clay cement (LC3) under sustained tensile and flexural loadings. The experimental tests conducted on LC3-FRPC specimens in two orthogonal directions were individual creep and shrinkage to determine other parameters associated with creep responses, including creep fracture. The specimens for tensile and flexural creep were subjected to sustained stresses of 40, 60 and 80 % of the tensile and 40 % flexural strength results obtained from quasi-static tests. The quantified creep is compared in terms of the difference in stress levels, as the results revealed that none of the specimens fractured under sustained loadings. Instead, higher direct tensile strengths were recorded for the creep specimens after 225 days loaded at different stress levels. Then, it is postulated that direct tensile tests on similar LC3-FRPC specimens without creep loading may confirm that the monotonic stress-strain response at the age at which the tests are terminated forms an envelope for creep fracture.

Analysis of the Effect of Layer Height on the Interlayer Bond in Self-Compacting Concrete Mix in Slab Elements.

This paper presents a study on the influence of the layered casting technology of self-compacting concrete (SCC) on the load-bearing capacity of interlayer bond in slab elements. The research was conducted on slab elements with dimensions of 750 × 750 × 150 mm, concreted from a single point of concrete delivery. The aim of this study was to analyse the influence of the height of the concreting top layer on the bond strength between the layers. The study utilised top layer heights of 50, 75, and 100 mm, which, according to the authors' experience, are the most common cases when making slab elements. The interlayer bond was determined by investigating the splitting tensile strength of cubic specimens cut from the concrete slabs. Computed tomography (CT) was employed to image the contact zone between the concrete layers. Based on the analysis of the CT imaging and the results of the strength tests, it was shown that the interlayer bond is influenced by both the height of the top layer and its free-spread distance from the casting point. A reduction in the interlayer bond strength was observed with decreasing the height of the top layer and increasing distance from the mixture supply point. The relationships obtained were linear and had a clearly negative slope. It was concluded that the valid recommendations and standards for the multilayer casting of SCC are too general. Therefore, we propose to detail the recommendations to reduce the risk of cold joints, which diminish the bond strength of the interlayer joints.

The influence of interlayer bonding conditions on the propagation laws of reflective cracks in semi-rigid base pavement based on the DEM and GPR

Reflection cracks represent the predominant internal distress in semi-rigid base asphalt pavements and often accompanied by additional secondary issues that detrimentally affect the pavement structural bearing capacity. The propagation and deterioration of reflective cracks are affected by many factors, for example the interlayer bonding conditions. It is crucial to identify the propagation and deterioration of reflective cracks to prolong the life of pavement structure. The purpose of this article is to explore the influence of interlayer bonding conditions on the propagation laws of reflective cracks. This work employs the discrete element method(DEM) to explore the propagation patterns of reflection cracks accompanied different bonding conditions between the surface layer and base layer subjected to moving load. The results of discrete element simulation reveal a three-phase progression laws when the reflective cracks expand from the base layer to the pavement surface，involving rapid propagation, stable propagation, and failure process. With the interlayer bond strength decreases, expansion of reflective crack is significantly accelerated. Meanwhile, once the critical bond strength threshold is reached, complete debonding will occur between the surface and base layers. The results are ultimately verified through the core sampling from practical engineering using three-dimensional (3D) ground penetrating radar(GPR) detection, along with the radar image recognition of reflective cracks and poor interlayer bonding. The results will serve as a foundation for researching the mechanism and treatment measures for two internal pavement distress, namely reflection cracks and poor interlayer bonding.

Interlayer Bond Strength of 3D Printed Concrete Members with Ultra High Performance Concrete (UHPC) Mix

Interlayer Bond Strength of 3D Printed Concrete Members with Ultra High Performance Concrete (UHPC) Mix

Nano-SiO2/polyurethane modified unsaturated polyester resin mortar for thin layer repairing on airport pavement

This paper introduces a novel toughened polymer mortar designed for runway repair, featuring outstanding impact resistance, high strength, and cost-effectiveness. To augment the toughness of unsaturated polyester (UP) polymer mortar, nano-SiO2 and polyurethane (PU) were incorporated. Firstly, the optimal dosages of nano-SiO2 and PU were determined through tensile test and impact test. Then, the modification mechanism of nano-SiO2/PU on UP resin was explored by microscopic image technology. In addition, the compression, flexural, fluidity, flexural bond strength and construction time tests were carried out to determine the optimal formula of nano-SiO2/PU modified UP resin mortar. Finally, the durability, impact resistance, impermeability resistance, skid resistance, and interlayer bond strength of modified UP resin mortar were studied and compared with those of pure UP resin mortar and epoxy (EP) resin mortar. Results show that the optimum proportion by mass for nano-SiO2/polyurethane modified UP resin is, UP resin: PU: dibutyltin dilaurate: nano-SiO2: initiator: accelerator: diluent: plasticizer = 1: 0.1: 0.002: 0.01: 0.01: 0.01:0.15:0.01. Furthermore, the mass proportion of modified UP resin to aggregate is 1: 1.2. In nano-SiO2/PU modification of UP resin, the -NCO groups of PU have been involved in chemical interaction with the -OH group of UP, while nano-SiO2 and UP resin are blended physically only. Compared with pure UP resin mortar, the nano-SiO2/PU modified UP resin mortar exhibited a 44% reduction in shrinkage rate, approximately 20% less corrosion loss, a 32% decrease in freeze-thaw loss, a 37% improvement in impact resistance, and increased shear bonding strength, flexural bonding strength, and tensile bonding strength by 44%, 33%, and 47%, respectively. Although the modified UP resin mortar demonstrated slightly lower performance in terms of dry shrinkage, corrosion resistance, skid resistance, and tensile bond strength compared to EP resin mortar, its freeze-thaw durability, impact resistance, flexural bond strength, and shear bond strength surpassed those of EP resin mortar. All three materials exhibited excellent impermeability. Leveraging the advantages of PU and nano-SiO2, the modified UP resin presents a promising repair material for airport pavement with enhanced toughness, high stability, and reduced cost.

Effect of absorption kinetics of superabsorbent polymers on printability and interlayer bond of 3D printing concrete

This study examines the effect of the material characteristics of superabsorbent polymers (SAPs) on the printability and interlayer bond strength of 3D printing concrete. Three types of SAP, including two acrylamide-co-acrylic polymers with coarse and fine particle sizes (S1 and S2) and an acrylic copolymer (S3), were employed. The investigated mortar mixtures had a fixed initial mini-slump flow of 195 ± 10 mm and yield stress of 290 ± 25 Pa. The fluidity of SAP-incorporated mortars was maintained by either adjusting the superplasticizer dosage or increasing the water content. Test results indicate that particle flocculation is dependent on SAP absorption kinetics shortly after the end of mixing. The use of S1 and S2 SAPs exhibiting high retention ability enhanced thixotropy, whereas the S3 SAP with rapid desorption reduced thixotropy. The S2 SAP improved the bridging effect of nucleation at early age due to its finer size, leading to a significant increase in the structuration rate at 30 min. Pull-out strength test and splitting tensile strength test were used to investigate the interlayer bond strength. The S1 SAP was the most significant in maintaining a higher internal relative humidity (IRH), thus resulting in higher 28-d interlayer bond strength, while the S2 SAP exhibited an intermediate ability to maintain elevated IRH, thus resulting in higher increase in 7-d interlayer bond strength.

Preparation of Structure-Function Integrated Layered CNT/Mg Composites.

Magnesium (Mg)-matrix composites have excellent damping and electromagnetic shielding properties. However, the mismatch between their strength and toughness limits their wide application. The aim of this work is to overcome the strength-toughness mismatch by constructing micro- and nanostructures while maintaining the good functional properties of Mg-matrix composites. Electrophoretic deposition (EPD) was used to spread carbon nanotubes (CNTs) out evenly on a Mg foil matrix. After spark plasma sintering (SPS), the grain organisation was refined, and the interlayer bonding was strengthened by hot rolling deformation. Finally, the microstructure, mechanical properties, damping properties, and electromagnetic shielding properties of the composites were analysed. Compared with the pure Mg laminates, the tensile strength and elongation of the CNT/Mg laminates were increased by 6.4% and 108.4%, respectively, with the significant improvement in toughness resulting from the increase in energy required for crack propagation due to the laminate structure. When the total rolling deflection reaches 80%, the interlayer bond strength of the material is significantly increased, the grain is further refined, and the strength and elongation of the composite material reaches the optimum, with the tensile strength reaching 241.70 MPa and the elongation reaching 6.90%. The interlayer interface and grain refinement also affected the damping Mg and electromagnetic shielding effect of the composites. This work provides an experimental idea for the preparation of high-performance structure-function integrated Mg-based materials.

Fused granulate fabrication of injection molding inserts from high-performance ULTEM 9085™ thermoplastic for cosmetic packaging industry

RTIM refers to the integration of rapid tooling (RT) using additive manufacturing (AM) with injection molding (IM). Due to the use of raw material (pellet), screw extrusion, fused granulate fabrication (FGF) allows for a cost-effective and versatile production of RTIM inserts especially compared to other material extrusion (MEX) AM processes, such as fused filament fabrication (FFF). This study 3D printed RTIM inserts out of high-performance thermoplastic polyetherimide (PEI) (ULTEM 9085) in granular form, using an in-house developed FGF system. A cosmetic compact was used as a case study part with a simplified design. A dynamic mechanical analysis (DMA) conducted on FGF ULTEM 9085 demonstrated that the strength of the inserts is sustained up to 140 °C, which suits injection molding using polypropylene (PP). Optical profilometry of the FGF 3D printed RTIM inserts demonstrated that when using a 0.4 mm nozzle, the flat surfaces produced had microscopic gaps larger than 10–1 mm. These gaps are sufficiently large so that melt of low viscosity polymer is able to flow through, which leads to undesired part flash. The IM experiments confirmed that the inserts were capable of producing PP parts but with the predicted flash. Simulated part deflection differed both on geometry and magnitude from the actual deflection measured by optical profilometry. A total of 36 prototype parts were produced before the inserts failed due to poor inter-layer bond strength. FGF RTIM using ULTEM 9085 is deemed suitable for prototype part production. Improving the inter-layer bond strength and decreasing part complexity could increase the number of parts produced.

Optimization of fiber reinforced lightweight rubber concrete mix design for 3D printing

A novel lightweight insulation concrete for 3D concrete printing is developed in this study, which incorporates crumb rubber (R) as a modifier to achieve low density, exceptional thermal insulation properties, and high ductility. The mechanical properties and fiber reinforcement mechanism of lightweight rubber aggregate concrete (CR) are investigated under varying R substitution rates, encompassing compressive strength, flexural strength, tensile strength, and tensile strain of CR. The thermal conductivity test offers insights into the thermal insulation mechanism of CR. The study investigates the compatibility between the material properties of fiber reinforced rubber concrete and the parameter matching of concrete printing equipment, as well as explores the relationship between interlayer bond strength and material composition. The optimal water-binder ratio for 3D printed fiber-reinforced lightweight rubber concrete compatible with printer equipment is determined through fluidity experiments and buildability tests. The findings indicate a statistically significant decrease in CR density by 16.5% when the replacement rate reaches 30%. Although the mechanical strength of CR decrease with the increasing substitution rate of R, the tensile strain showe an increasing trend. The addition of glass fiber reinforcement resulted in a notable enhancement of the mechanical properties and a significant increase in tensile strain for CR. In addition, CR thermal conductivity is reduced by 20.65%, with the excellent thermal insulation performance. This study is of great significance to promote the rational utilization of rubber resources, promote the development of circular economy, and build a conservation-oriented and environment-friendly society.

The effect of interlayer adhesion on stress distribution in 3D printed beam elements

Interlayer adhesion is one of the most pivotal aspects related to mechanical performance and durability of 3D printed concrete. However, due to continuous printing of multi-layered structures, large-scale buildings require long time intervals between layer deposition, with interlayer bond strength decreasing as time intervals between printed layers increase. This study evaluates comprehensively the effects of time intervals between layers: 1 h, 1.5 h, 2 h, 3 h, and 4.5 h as well as two different height to span ratios (hb/s). In order to assess the properties of interlayer regions microstructural examinations using techniques such as X-ray micro-computed tomography (micro-CT), scanning electron microscopy (SEM) were applied. In addition destructive testing of compressive, splitting tensile and flexural strengths along with crack opening analysis using the Digital Image Correlation (DIC) method was performed and supported with FEM analysis. The results show that interlayer adhesion strength decreased significantly for time intervals of up to 2 h, with a linearly decreasing trend. The reduction in strength the interlayer bond for a 2-h interval was 56.6%, compared to the reference specimen. Afterwards, the decrease in strength was minimal (up to 68.5% after 4.5 h time interval). However, microstructural investigations revealed that specimens with printing interval beyond 2 h exhibited noticeable continuous cracking in interfacial zone with widths reaching of up to 100 μm (SEM). At the same time micro-CT analysis confirmed creation of longitudinal pores which in turn was reflected in different cracking phenomena of specimens with longer printing intervals (>2 h). This phenomenon was further explained through FEM modeling. As an outcome it was proven through DIC that that increasing the time interval between the deposit of successive layers not only affects the strength of the entire beam, but also affects its cracking mode. The discontinuities in the interlayer contact zone leads to destruction characteristic of composite structures, thus the structure comes to be destroyed layer by layer, resulting from insufficient interlayer adhesion. The presented study is the first to fully evaluate the failure behavior of 3D printed specimens with long time intervals.

Laboratory cracking and interlayer bond strength performance characterization of full-scale accelerated geosynthetic reinforced asphalt concrete

This study was conducted to evaluate the performance of geosynthetic reinforced asphalt pavements through full-scale and laboratory testing. The study also investigated the field cracking performance of geosynthetic test sections under accelerated loading and validated with the laboratory cracking performance results. Three sections were constructed including: control, geogrid and geosynthetic reinforced AC. After applying the accelerated loading, cores and slabs were extracted from the wheel path (W) and outside of the wheel path (OW) to evaluate the impact of accelerated loading on cracking performance of AC. The laboratory cracking performance and shear bond strength were assessed using Indirect Tension Asphalt Cracking Test (IDEAL-CT), Interlayer Shear bond Strength (ISS), Bending beam Fatigue (BBF), and Texas overlay tests. Additionally, strain response on top of pre-existing notch was also analyzed from the accelerated test sections to monitor field cracking potential of reinforced AC and to validate it with laboratory cracking performance. According to the BFF, OT and ISS results, the W AC showed degraded performance compared to OW AC, however, IDEAL-CT test results mentioned that W AC showed better cracking performance compared to OW AC. Overall, geosynthetic reinforced AC showed better laboratory cracking performance and lower shear bond strength. At full-scale section, higher tensile strains were registered indicating that geosynthetic reinforcement can undergo potentially larger displacement without failing in the pre-existing crack area. Both laboratory and field test results compliment the findings of each other.

Post-fire properties of lightweight 3D printed concrete containing expanded perlite

There has been an increase in construction with three-dimensional (3D) printing technology but 3D printed (3DP) structures also require weight reduction similar to conventional reinforced concrete structures. In addition, the behaviour of this type of structure against fire needs to be investigated. The number of printed layers and the time gap between layers for the 3DP specimens were among the variables examined. The test results demonstrate that as the replacement percentage of natural sand (NS) with expanded perlite (EP) increased, at 25% volume of replacement, the interlayer bond strength increased on average by 18.6%, while at the highest replacement level, of 75%, the strength decreased on average by 5.8%. Additionally, by incorporating EP, the compressive and flexural strengths of 3DP specimens declined on average from 9% to 29.7%, and from 39.3% to 49.3%, respectively. As the replacement level of NS increased, residual compressive and flexural strengths increased after exposure to 800°C. Furthermore, it was demonstrated that exposure to high temperature had the least effect on interlayer bond strength, whereas it significantly reduced the compressive and flexural strength. The results show that increasing the time gap between layers reduced interlayer bond strength and flexural strength while negligibly affecting compressive strength.

An in-situ method to evaluate the interlayer bond between hot-mix asphalt and portland cement concrete surface

Proper bonding between different layers of a composite pavement is a major factor in ensuring that the entire structure acts as a monolithic layer under load. This paper studies the bonding between hot mix asphalt (HMA) overlay and Portland cement concrete (PCC) pavement using tack coats. An in-situ pull-off test method was developed for use on project sites on a routine basis to screen and test the quality of bond between asphalt layer and concrete layer. This test replaces the arduous process of coring through often times very thick concrete layer with steel rebars, transporting the core to a lab, trimming the concrete side of the core to fit the shear jig, and finally conducting a shear test. Results show that the in-situ pull-off test method developed in this study is strongly correlated to the laboratory based direct shear test. Limits were also suggested to indicate an adequate bond strength in the PCC–HMA interlayer on the basis of laboratory and field testing. This study also evaluates the influence of various factors on the performance of the interlayer bond in laboratory. These factors include the type of tack coat, application rate, the texture of the concrete pavement surface, the surface cleanliness and the surface moisture. Results indicate that sandblasting and hydro-demolition textures offer the best interlayer bond strength, the influence of application rate is not significant on the interlayer bond strength and the influence of surface moisture and cleanliness are dependent on the type PCC surface texture.

Mechanical properties of concrete reinforced with high-performance microparticles for 3D concrete printing

Given its exceptional mechanical properties, ductility, and durability, high-performance concrete (HPC) has become a focal point of research in the field of 3D concrete printing (3DCP) in recent years. To further enhance material properties, particularly compressive capability, flexural capacity, and interlayer bond strength, HPC that incorporates micron materials based on fiber reinforcement is presented in this study. Mechanical properties and microstructure are analyzed to explore the microparticle enhancement mechanism. Then, a self-developed 3DCP system is utilized to verify the printability of materials and achieve the regularity of print parameters and interlayer bond strength. Furthermore, the effects of micron materials on the properties of HPC are evaluated though group comparison. The optimal material and dosage of HPC under different properties are obtained by conducting a comparative analysis of the test results for various properties of three different materials. The current work not only creates HPC that enhances material properties, but also restores confidence in the development of 3D printing for the utilization of construction waste resources.

Uniaxial tensile study of calcium aluminosilicate hydrate (C-A-S-H): Structure, dynamics and mechanical properties

Calcium aluminosilicate hydrate (C-A-S-H) is the main hydration product of environmentally friendly concrete, which uses aluminum-rich industrial waste residue to partially replace cement raw materials. In order to understand the structure and properties of C-A-S-H gel at the molecular level. The structure, dynamics and mechanical properties of C-A-S-H gel at different Al/Si ratios were studied by reactive molecular dynamics simulation. The results showed that the doping of aluminates substances caused changes in the silicate-aluminate skeleton and inter-layer water molecules in C-A-S-H gels. As the Al/Si ratio increased, more water molecules dissociated and associated with Al atoms to produce Al-O(H)-Si and Al-OH. In addition, the presence of Al-O-Si chains not only imposed geometrical constraints on the inter-layer water molecules, but also increased the attraction of the substrate for water molecules. Furthermore, the mechanical behavior and deformation mechanism of C-A-S-H gels were investigated based on uniaxial tensile tests. The inter-layer bond strength and stiffness of C-A-S-H gels increased significantly with increasing tensile load and aluminate branching structure.

Development of CO2-integrated 3D printing concrete

3D printing concrete (3DPC) technology is a promising technique for construction due to its advantages such as no formwork is needed, fast production, automation, and high architectural freedom. However, the layer-by-layer extrusion method has stricter requirements on the rheological properties of concrete. One of challenges of this technology is how to improve the rheological properties of concrete to satisfy the conflicting requirements during pumping and after extrusion. This study proposed to use CO2 as accelerator and rheology modifier by injecting CO2 during secondary mixing to improve the rheological and mechanical properties of 3DPC. The influences of the secondary CO2 mixing on the properties of poured concrete and 3DPC were investigated. After using the secondary CO2 mixing, the setting time and workability of concrete were reduced, which contributed to the significantly improved buildability of 3DPC. This was because CO2 accelerated the hydration of tricalcium aluminate (C3A) and tricalcium silicate (C3S) during the secondary mixing. After that, they were continuously accelerated by the calcium carbonate formed during CO2 mixing. Also, the compressive strength of poured concrete was enhanced by the secondary CO2 mixing because it reduced the volume of larger pores (>200 nm) and promoted the formation of calcium silicate hydrates (C-S-H), which simultaneously slightly increased the drying shrinkage. In addition, after using the secondary CO2 mixing, the compressive strength and interlayer bond strength of 3DPC was enhanced.

Analysis of Interlayer Crack Propagation and Strength Prediction of Steel Bridge Deck Asphalt Pavement Based on Extended Finite Element Method and Cohesive Zone Model (XFEM–CZM) Coupling

The extended finite element method (XFEM) was employed for the computational modeling of internal defects within a bond layer. Furthermore, a cohesive zone model (CZM) was implemented to characterize the behavior of the bond layer in response to interactions at both the bond layer/steel plate and bond layer/asphalt paving layer interfaces. The coupling of XFEM and CZM was used for a comprehensive analysis of crack propagation within the bond layer as well as the assessment of phenomena associated with interfacial debonding and delamination. The feasibility and accuracy of the XFEM–CZM coupling method were verified by comparing it with the virtual crack closure technique (VCCT), CZM, XFEM–VCCT, and experiments. A double cantilever beam experimental model was established to simulate the process of interlayer-type cracks expanding from the inside of the bond layer to the interface between the bond layer and the upper and lower layers, causing debonding. This was undertaken to analyze the damage failure mechanism of interlayer-type cracks in asphalt paving layers of steel bridge decks; to discuss the impacts of the initial crack length, the interface stiffness, the interface strength, and the thickness of the bond layer on the performance of the overall interlayer bond strength; and to carry out the significance analysis. The results showed that the initial crack length, interface stiffness, and bond layer thickness had different effects on the expansion path of interlayer cracks. The interlayer strength decreased with an increase in the initial crack length and interface stiffness, increased with an increase in the interface strength, and decreased with an increase in the thickness of the bond layer. The interface stiffness had the most significant effect on the strength.

Slag-modified metakaolin-based 3D printed geopolymer: Mechanical characterisation, microstructural properties, and nitrogen physisorption pore analysis

This study aims to enhance metakaolin (MK)-based binders with slag up to 30% at 10% intervals and increase the aggregate-to-binder ratio (a/b) from 1.6 in a previous study to 2 for extrusion-based 3D printed geopolymer concrete (3DPGPC). Sodium phosphate (3% by mass of binders) was used to tailor the fresh properties of the slag-modified MK-based 3DPGPC mixtures to achieve sufficient open time for constructability. After 28 days of curing age, cylindrical 3DPGPC specimens cored perpendicular to the printing direction (D1) exhibit an average compressive strength of 23.7–31.52 MPa and the specimens cored parallel to the printing direction (D3) exhibit an average compressive strength of 25.25–33.13 MPa. Also, an increase in a/b from 1.6 to 2 increases the average compressive strength by 18% in D1 and 25% in D3. The average flexural strength of specimens in D1 attained 5.48–7.29 MPa, while the average interlayer bond strength of 3DPGPC beam specimens attained 5.40–6.90 MPa. An increase in a/b from 1.6 to 2 enhanced average flexural strength by 6%. Furthermore, the 28-day splitting tensile strength of cored cylindrical 3DPGPC specimens attained 1.79–2.16 MPa in D1 and 2.04–2.43 MPa in D3. Microstructural characterisation revealed the formation of C-S-H, N-A-S-H and C-A-S-H gel with increasing slag inclusion due to the presence of Ca2+ion. Nitrogen physisorption analysis shows that the adsorption and desorption isotherm curves and hysteresis loops were not altered but more nitrogen by volume was absorbed due to the formation of a significant quantity of C-S-H, N-A-S-H and C-A-S-H gel. The adsorption and desorption isotherms fall under the mesopores structure of 2–50 nm using the IUPAC technical report classification. The Brunauer-Emmett-Teller (BET) surface area increases by 67, 69, and 78% as slag content increases by 10, 20 and 30% due to the polymerisation of the reactive phases, which densify the matrices. The enhanced mechanical performance, microstructural properties, and pore structure system of slag-modified MK-based 3DPGPC ascertained that it is suitable for construction applications.