Does the supervision of commercial concrete submitted by the general contractor need to attach the retest test report of sand, stone and cement raw materials? Should a mixing station be provided?

Do a good job, that is, make it clear in the commercial and mixed procurement contract that the construction party should inform the supervision unit before distributing the corresponding commercial and mixed products at the commercial and mixed station according to the design drawings, and the sampling witness of the supervision unit and the sampling personnel of the construction unit shall jointly complete the sampling witness procedures and send them to the testing unit for testing. When the business is mixed to the construction site, it is necessary for the supervision unit personnel to witness the sampling and make concrete test blocks.