When it comes to testing concrete during placement, the most commonly used method for evaluating strength is the break test. Break tests require concrete sample cylinders to be subjected to high amounts of pressure in order to assess the material’s compressive strength. Although this test method is widely accepted, results found in the laboratory are often not representative of the in-situ element. Curing conditions, the size of the cylinders compared to the onsite concrete element, and transportation to the laboratory of field-cured specimens are all factors which can skew the setting, hardening and strength performance of the cylindrical concrete samples in comparison to the actual structural elements made from the same concrete material.
Technological advancements have made it possible to obtain in-place strength data faster, without performing break tests. In particular, SmartRock™, the most widely used wire-free concrete sensor in the world, helps construction companies build structures faster, more safely, and more efficiently. These user-friendly sensors are easily installed in the formwork (on the rebar) before pouring to continuously monitor the in-situ temperature and maturity of concrete, according to the ASTM C1074, Standard Practice for Estimating Concrete Strength by the Maturity Method.