Long waiting times are the killer of every construction site. This is especially true for concrete casting because the compressive strength of the concrete is usually tested in the laboratory. Until the results are available, nothing happens, resulting in a significant reduction in productivity. At the same time, the maturing process could well be so far advanced that the formwork can already be removed. Concrete monitoring helps you to shorten project time. You can check the maturity progress yourself and massively reduce the construction time. The way to more productivity is as simple as that.
Newsletter – Concrete Monitoring
How is compressive strength usually measured?
Compressive strength testing is carried out in the laboratory using specimens specially prepared for this purpose. These are either concrete cylinders that are 30 cm long and have a diameter of 15 cm, or test cubes with an edge length of 15 cm. According to the DIN standard for structures made of normal, light, heavy, prestressed and high-strength concrete, this is done 28 days after casting. The strength class is then expressed in N/mm² according to the maximum pressure withstood – for example as concrete C20/25 for Concrete with 20 N/mm² for the cylinder and 25 N/mm² for the cube.
Waiting for laboratory values can extend construction time
In practice, however, the compressive strength may well be reached well before the specified time. This is because the maturing process depends, among other things, on the hydration temperature and the weather. Waiting for lab results then leads to unnecessary delays. After all, stripping or re-tensioning could well be done ahead of time, which would significantly shorten the construction time. Instead, the construction site is at a standstill, which is not only inefficient but also expensive. Every delay costs money and ties up unnecessary resources and manpower. Moreover, it is very difficult to make up for. It’s not for nothing that major projects are often 80 percent over budget and 20 months behind schedule.
