Precast sites have some key challenges where sensors can provide a significant benefit. Examples of these could be:
Today precast sites often produce after fixed plans, templates and schedules. As a result, precast producers have to set plans after worst-case scenarios, so you even in the wintertime are able to produce concrete products without defects and remove the formwork without any safety issues. This means often time is wasted and the constant running heating on concrete is wasted when waiting on concrete.
In many regions, there is a tradition of performing a concrete compression test on concrete specimens (cubes or cylinders) a so-called break-test. The challenge with these specimens is that they are not cured under the same conditions, as the much larger concrete element has the ability to create and store a lot more heat inside from the hydration process. The temperature will therefore often be higher inside the structure compared to the specimen cured next to the element. This means you won’t have the same strength inside your specimens (often lower) compared to the concrete element.
When this is said, specimens are very good (and often required) for validating the final 28-day strength of the concrete.
Read more about concrete break-tests vs. maturity methods here.
Before removing a formwork, start lifting an element with the crane or for prestressed elements to start cutting the wires are activities, you have to be sure the required strength is there. Otherwise, you might either increase the risk of fatal errors like dropping an element in an area with people or you might start experience challenges with product defects like cracks, wire slippage (wire traction) or similar
Sometimes you might be required to do some data logging of temperatures in your concrete. This might involve tasks like manual data import on a pc, data calculations in Excel, setting up reporting in word and finally storing a concrete report in a PDF in a secure database. Many of these tasks can be automatically handled by using a wireless sensor solution in combination with a software solution.
Nothing lasts forever, and especially not in a rough environment like in precast production. Things break and stop working, which can cause delays in production or product claims. Managing the production with sensors with continuous real-time data with a combination of statistic module, might enable you to identify unhealthy trends in the data like the reduction of heating in some beds, increased temperatures in water tanks or similar.
Using wireless concrete sensors as part daily production of precast elements gives a unique set of opportunities.
Embedding wireless sensors in concrete gives you the opportunity to monitor concrete temperature, concrete maturity, and concrete strength. Knowing the concrete strength in real-time (some systems also enable a prediction) enables you to know exactly when your concrete element is ready for being moved and new concrete can be poured in the form. This enables you to speed up your production and increase production capacity.
Heating is often used in precast productions to ensure a fast curing time but is often badly managed as well. Many precast productions use a standard daily “template” of when they heat the beds either from underneath with hot water/steam or from on top with air / infrared heaters. As a result of the fixed heating, a lot of heat is wasted for continued heating when the needed concrete strength has been reached.
Concrete break tests are good indicators of if you’re able to obtain a certain strength as the final strength after the traditional 28-days, but they are not really good indicators of the continuous strength development of the concrete in the form. Wireless sensors are therefore very good indicators of this, and you will therefore be able to replace many of the break tests used for other purposes than the 28-days strength confirmation – like the hourly or daily strength tests you are during to follow your castings along the way.
✓ Gain insights into the curing process measured directly inside the structure
✓ Include external influence factors such as weather conditions in the calculations
✓ Rely on data-driven decisions
✓ User-friendly dashboard with status display
All data is automatically stored in PDF’s ready to download or print. The reports are updated every 10 minutes when new data is received and contains both data from the concrete, temperature, and humidity for the ambient air and concrete KPI’s like maximum temperature, production time etc.
Everything done automatically without any use of labor – this is what we call automatic reporting.
By embedded sensors on a daily basis you might be able to see any sudden changes in the data, which could indicate an issue with some equipment or other issues. Normally this can take weeks or months to identify these types of problems (like a leaking heating pipe, abnormal water temperatures in tanks or similar). A good statistical module will help you to identify these types of problems.