I. Qualification of witnesses

1. The witness shall be a supervisor with knowledge of construction inspection and test and trained; After the witness is determined, it shall promptly notify the engineering quality supervision institution and the testing institution that undertakes the corresponding witness test. Fill in and submit the witness notice of witness sampling and inspection.

Second, when the witness changes.

When the witness personnel change, the supervision unit shall notify the testing institution and the supervision institution, and the replacement of the witness personnel shall not affect the witness sampling and inspection.

Iii. Witnesses witness the whole process of sampling and inspection.

For the items that need witness sampling and inspection, the construction unit shall notify the witness to be present before sampling. Witnesses shall witness the whole process of sampling and inspection, and fill in witness records. Test (sampling) personnel and witnesses shall sign the witness record.

Four. Witnesses shall abide by relevant regulations.

Witnesses should check whether the witnessed items, quantity and proportion comply with relevant regulations. In addition to the above-mentioned documents, witness sampling and inspection on the construction site shall also comply with the provisions of the Technical Management Code for Testing and Testing of Building Engineering.

Working procedure of witness sampling

First of all, before the project construction

By the construction unit and project supervision institutions * * * and witness sampling inspection institutions jointly determined. For the laboratory proposed by the construction unit, the professional supervision engineer should conduct on-the-spot investigation. The laboratory is generally a third party that has no administrative affiliation with the construction unit.

Second, submit it to the institution in charge of this project for the record.

The project supervision institution shall submit the selected laboratories to the quality supervision institution in charge of this project for record and recognition, and the professional supervision engineer in charge of witness sampling in the project supervision institution shall record in this quality supervision institution.

Three. Field sampling

The construction unit shall, in accordance with the provisions, formulate a test plan, equip sampling personnel, be responsible for the sampling work at the construction site, and submit the test plan to the project supervision institution.

Fourth, complete the sampling process.

Before witnessing the sampling of materials, test blocks, test pieces and steel bar joints at the site, the construction unit shall notify the professional supervision engineer responsible for witnessing the sampling. The construction unit shall complete the sampling process of materials, test blocks and test pieces in accordance with the requirements of relevant specifications under the on-site supervision of professional supervision engineers.

Five, after the completion of sampling, send it to the laboratory.

After the sampling is completed, the sampling personnel of the construction unit shall mark and seal the samples or their packages. The logo and seal shall indicate the project name, sampling location, sampling date, sample name and sample quantity, and shall be signed by the professional supervision engineer who witnessed the sampling and the sampling personnel of the construction unit.