Concrete specimens are standardised for 28 days before they can be judged whether the concrete from the factory meets the design requirements, and the same specimen of concrete poured on site is 600°C - d as the standard of judgement, and in winter construction, if the average daily temperature is 10°C, it will take 60 days of maintenance to judge whether the strength of the structure meets the design requirements.

For ready-mixed concrete mixing plant, to ensure that the strength and performance of the concrete factory, the ratio is fundamental, and the quality of raw materials before the preparation and production of concrete, raw materials with the use of "ahead" control is the key.

In addition, due to the lack of supervision of the concrete pouring site, the construction personnel to pursue self-levelling concrete pouring, adding water is serious; even if the quality of ready-mixed concrete factory qualified, the site will lead to a straight-line drop in concrete strength after adding water.

Sand, stone in the concrete in the largest amount, its quality will directly affect the quality of concrete, which sand and gravel particle size, particle shape, grading, mud content, stone powder content, moisture content and other parameters fluctuations, if the concrete ratio is not adjusted accordingly, its work performance and strength will be deviated.