Standard curing means curing according to test standards to test whether the strength of concrete meets the design requirements. Although the concrete is mixed according to the design requirements, the quality will fluctuate due to various reasons, such as weather, humidity and cement batch, so it is necessary to check whether the finished product meets the design requirements.

Co-education is to maintain health according to the working environment of concrete, so as to understand the strength development of concrete in this environment. For example, when pouring concrete in offshore docks, it is necessary to have co-cultured specimens to test whether the concrete strength meets the requirements in seawater. In this case, the strength of the specimen must be different from that of the specimen preserved in the laboratory.