Just as its name implies, sprayed concrete is the act of blasting or spraying the substance onto the surface instead of laying it out traditionally and letting it settle. The process is faster and can be used in numerous settings where the traditional method is not appropriate.
During the middle of 2016, a new system that makes use of thermal imaging to evaluate the strength of sprayed concrete tunnel linings was trialled for the very first time in London. If implemented into the industry it could lead to improvements in safety, productivity in the long term and quality. The technique gives everyone a better picture of what the entire lining is doing, as opposed to extrapolation from a panel of a small location of lining.
Testing methods presently in use for sprayed concrete include using penetrometers, using test panels sprayed at the same time, and taking samples. The use of thermal imaging has been in the works since 2011 and since then, it has gone through multiple phases that have seen research being conducted both in laboratories and within the field.
The technique consists of using a thermal imaging camera, which is placed at a safe distance, to measure the concrete’s temperature at various time intervals. Using software, the temperature measurements are then transformed into compressive strength quantities. With more accurate measurement, contractors can strike forms much quicker, cutting programme periods and potentially making big savings. In addition, they will be able to supply long-term quality monitoring to a project.
At Churchill Concrete Technology, we have a lot of experience with sprayed concrete and understand how tricky it can be to test it using current methods. We are excited about the prospect of a faster, more accurate option that could provide the array of benefits above. We will be keeping a close eye out for developments.
If you have any questions about sprayed concrete, whether it is laying it, testing, or conducting repairs we would be happy to help.