Guangzhou launches quality inspection of precast concrete components
The quality of precast concrete segments and prestressed concrete piles is directly related to the safety of the construction project. As a structure of subway tunnel support system, precast concrete segment is a key part of the tunnel structure; prestressed concrete pipe pile is also an important building component and a “constant sea needle” supporting the building, both of which are key parts of the construction project. In order to strengthen the quality supervision of these two types of products, from the late October onwards, the Guangzhou City Municipal Bulk Cement Management Office carried out random inspections of raw materials and product quality for prefabricated concrete structural enterprises. In addition to testing the overall quality of the product, the sampling inspection also includes special inspections of raw materials, control from the source, and the quality of construction projects. According to the “Dual Random Public” mechanism, this sampling inspection randomly selects inspection subjects, randomly selects law enforcement inspectors, implements sunshine law enforcement, and enhances impartiality. After completion of random inspections, relevant conditions will be disclosed to the public.
Prior to the inspection, the Office formulated a detailed plan, and specified the number of samples, testing items, personnel composition, and time schedule according to the relevant standards and work practices, and organized experts to discuss and revise the plans so as to be scientific and reasonable and feasible. Chen Jikai, the director of the office, has approved the sampling inspection program and required the inspection personnel to strictly observe the standards and strictly observe the disciplines, and to actually inspect the quality level of the company to ensure the quality and safety of construction projects in the city.
It is reported that this time will random inspection of cement, sand, stone, admixture, fly ash, slag powder, steel, PC steel rod, end plate and other 9 different specifications of raw materials, according to the current national standards to detect the relevant performance, the sample cross blind Submit the inspection to ensure that the test result is true and fair; the segment will be tested according to "precast concrete lining segment" (GB/T 22082-2008) to check the appearance quality, size deviation, horizontal assembly, leak test, bending performance, and pullout resistance The content of chloride ions in the cerium is measured by the rebound method. The pipe piles will be tested according to the "Pretensioned prestressed concrete pipe piles" (GB 13476-2009) to check the appearance quality, allowable size deviation, thickness of the protective layer, and bending resistance. Performance, using drill core sampling sampling test concrete strength and chloride ion content, and whether the actual measurement of pile reinforcement in the production line is in line with the "National Building Standard Design Atlas - Prestressed Concrete Pipe Pile" (10G409) requirements.
It is understood that there are seven pipe pile enterprises in our city, and there are five segment companies (six production sites). In addition, one Shenzhen company (two production sites) supplies pieces to the subway project in Zhongshan City, Zhongshan, Four companies in Dongguan supplied pipe piles to the city's housing and shelter project. For these enterprises outside the city, sampling inspections will also be carried out to add another “insurance” for the quality and safety of key projects in our city.
At present, sampling inspections are being carried out as planned.