Viscosity is a key parameter in 3D concrete printing, influencing printability, structural stability, and interlayer adhesion. Hydramotion inline viscometers provide real-time viscosity monitoring to maintain process consistency and product quality.
Featured Hydramotion sensors for 3D Concrete Printing:
XL5 Sensor 2" Tri-clamp |
XL7 Sensor 2" Tri-clamp |
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3DCP Process Overview
3D concrete printing (3DCP), also known as concrete additive manufacturing, is an emerging construction technology increasingly being explored for house building, commercial construction and a range of civil engineering applications, including bridge construction and infrastructure components.
The process involves extruding cement-based mixtures directly from digital models to build structures layer by layer, similar in principle to polymer 3D printing but using cementitious materials. This approach can reduce the need for formwork, enable complex geometries and offer potential cost and material savings compared with conventional construction methods.
Viscosity plays a central role in the process, influencing the consistency of material flow, interlayer bonding and the ability of freshly printed concrete to retain its shape under the weight of subsequent layers.
The 3DCP process is structured around four main stages:
Mixing
Cement, sand, and additives are combined to create the core mixture. Formulations balance flowability during pumping with strength after deposition, often using retarders and accelerators to manage setting times. The formulation is mixed continuously with water as part of the hydration process.
Secondary mixing may occur before extrusion depending on further additive requirements to optimise material stiffness and strength.
Pumping
Progressive cavity pumps deliver the fresh mix to the printing nozzle. Flow consistency is critical to avoid print interruptions and maintain structural build rate.
Extruding
A nozzle is mounted on a robotic arm or gantry and deposits the material through controlled extrusion.
Building
The extruded material is deposited in programmed layers, allowing the structure to be built progressively as each layer supports the next.
Process Challenges and Viscosity Control
Concrete’s dual rheological behaviour - acting more like a solid below a certain shear stress and flowing like a fluid when sheared - creates processing challenges that directly affect print quality and performance.
The material must pump easily but stiffen quickly enough to hold its shape after extrusion, while also supporting its own weight and bonding effectively with adjacent layers. Viscosity is a key factor throughout this process, influencing how the material behaves during mixing, pumping and extrusion and ultimately how consistently it can be deposited. Controlling viscosity therefore helps maintain the balance between flowability, buildability and structural integrity.
If the viscosity is too low, the material may flow too readily, causing layers to slump or collapse. If it is too high, pumping becomes difficult and the nozzle can clog. Measuring viscosity in real time provides operators with the feedback needed to monitor these changes and make adjustments quickly, helping to maintain consistent flow, reliable extrusion and print quality.
While yield stress is also central to the broader rheology profile, viscosity is a practical parameter for process control because it directly reflects resistance to flow and provides a useful indication of material consistency during mixing, pumping and extrusion.
Inline Viscosity Monitoring Solution
Hydramotion viscosity sensors are well suited to concrete measurement and the 3DCP process due to their robust and high performance nature. The sensors can be installed in either the mixing, pumping or extrusion process phases with no on-site modification required, and can operate continuously without interrupting production flow.
XL5 Sensor 2" Tri-clamp |
XL7 Sensor 2" Tri-clamp |
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The dedicated readout unit can be located up to 1000 metres from the sensor and include 4-20mA viscosity and temperature outputs along with an RS232 or RS485 serial data link for recording or remote monitoring.
This data can feed into predictive or closed-loop control systems, allowing automated adjustment of process conditions based on live viscosity feedback.
For optimal installation, the transducer is mounted either in the hopper or adjacent pipeline directly in the process flow. There are generally no limitations on pipe size or maximum flow rates, and engineered solutions are available to optimise installation points and exposure to flow.
Due to concretes composition and abrasive properties, all Hydramotion sensors have the option of fabrication from high strength alloys such as Super Duplex 2507, and are available with virtually any process fitting.
Typical dimensions can be seen below for an indicative XL5 sensor. Hydramotion also offers a bespoke design service - Special Ops - where a sensor of virtually any size or geometry can be designed to fulfil the requirements of the application.
Download indicative XL5 GA drawing file >
Welds are smooth and crevice-free with open construction for easy cleaning and to eliminate contaminant traps.
All viscometers are supplied with process fittings to match the connections that already exist on your equipment. This includes any size or type of sanitary fitting, including quick-release tri-clamp mountings, RJT, IDF, DIN, SMS, Varivent® and others.
Ready to learn more?
Contact Hydramotion to discuss your 3DCP application requirements. Or visit the following links to learn more about Hydramotion viscosity sensors.