(A) witness sampling provisions:
According to the Ministry of Construction Jianjian (2000) No. 211 "on the issuance of" housing construction and municipal infrastructure projects to implement the provisions of the sampling and inspection system "
Article 3: The provisions of the provisions of the witnessing of the sampling and inspection refers to the witnessing in the construction unit or the project supervision unit, by the construction unit on-site test personnel of the project involving structural safety test blocks and materials in the field sampling and sent to the construction administrative department at or above the provincial level, the construction unit to take samples of test pieces and materials in the project. Construction unit on-site test personnel of the project involves structural safety of the test blocks, test pieces and materials on-site sampling, and sent to the provincial level or above by the competent administrative department of the construction of its qualifications and quality and technical supervision departments of the measurement of its certification of the quality testing unit for testing.
Article 4 provides that: the state council administrative department of construction of housing construction projects and municipal infrastructure projects witness sampling and delivery of unified supervision and management.
Local people's governments at or above the county level, the construction of administrative departments of the administrative region of the housing construction projects and municipal infrastructure projects witness sampling and inspection work to implement supervision and management.
Article 5 provides that: involving structural safety of the test blocks, test pieces and materials witness sampling and delivery of the proportion shall not be less than 30% of the number of samples specified in the relevant technical standards.
(B) the scope of witness sampling:
According to the provisions of the following test blocks, test pieces and materials must be implemented to witness sampling and inspection:
1, for load-bearing structure of the concrete test blocks;
2, for load-bearing wall masonry mortar blocks;
3, for load-bearing structure of the reinforcing bars and connecting joints test pieces;
4, Bricks and small concrete blocks used for load-bearing walls;
5. Cement used for mixing concrete and masonry mortar;
6. Admixtures used in concrete for load-bearing structures;
7. Waterproofing materials used for ground floor, roofing, and toilets and bathrooms;
8. Materials or specimens used for road sub-base and surface layers;
9, Municipal engineering, the owner or supervision unit project director that is closely related to the quality of materials or components;
10, the state regulations must be implemented to witness the sampling and delivery of other test blocks, test pieces and materials.
Extended information
Requirements for witness sampling:
1, witness sampling involves tripartite behavior: the construction side, the witness side, the test side.
2, the qualification of the laboratory qualification management:
1) all levels of engineering quality supervision and testing organizations (with CMA chapter, that is, metrological certification, 1 year review).
② construction companies test room should be gradually transferred to the enterprise internal control organizations, 4 years review once.
Third-party test room inspection:
①Measurement certification, CMA chapter.
②Check attachments, filing certificates.
3, measurement certification is divided into two levels of implementation, one for the national level, one for the provincial level, the implementation of the effectiveness of all completely consistent.
4, witnesses must obtain the "witness certificate", and through the construction unit authorized, and authorized only to undertake the authorized project witness work. To enter the construction site of all building materials, must be implemented according to the specification requirements to witness sampling and delivery test, test report into the quality assurance information.
Baidu Encyclopedia-Witness Sampling