Validation is part of the ASTM-standardized maturity test method and is recommended periodically as a best practice to achieve the highest accuracy possible.
The maturity method is an ASTM-standardized, non-destructive test method for estimating concrete strength that provides real-time results. Typically, cylinders and beams are required to be cast and broken for quality control and 28-day acceptance. It is common practice to simply cast and break additional samples, sometimes referred to as companion samples, for estimating early-age strength of in-place concrete for purposes such as early form removal, post-tensioning of elevated slabs, and fast-track pavement construction and repair. However, the strength gain of these cylinders may not reflect the strength gain of the in-place concrete.
For example, when placing concrete in ideal or hot-weather conditions, strength gain will likely occur faster for in-place concrete than for companion cylinders or beams simply because of the difference in size and heat generation during hydration. For the same reason in cold weather, it may be that in-place concrete gains strength slower than companion cylinders particularly if companion cylinders are cured at warmer temperatures. Maturity bridges the gap between what is tested for in companion samples and what field conditions are assumed.
Maturity uses sensor technology to provide real-time updates of in-place temperature and age, allowing users to estimate strength based on a maturity curve developed by breaking cylinders or beams.
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