Vietnam: What are the technical requirements for autoclaved aerated concrete products under National Standard TCVN 7959: 2017?
- What are the technical requirements for autoclaved aerated concrete products in Vietnam under National Standard TCVN 7959: 2017?
- What are the regulations on shapes, dimensions, and conventional symbols for autoclaved aerated concrete products in Vietnam?
- What are the regulations on labeling, storage, and transportation of autoclaved aerated concrete products in Vietnam?
What are the technical requirements for autoclaved aerated concrete products in Vietnam under National Standard TCVN 7959: 2017?
Under Section 3 National Standard TCVN 7959: 2017 on terms and definitions for autoclaved aerated concrete products as follows:
Terms and definitions
This National Standard uses the following terms and definitions:
3.1 Autoclaved aerated concrete (AAC)
Lightweight concrete has a hollow structure, is produced from a mixture: of adhesives, raw materials with a high content of silicon oxide in the form of fine powders, gaseous and water forming agents, curing in a high-pressure warm-thermal environment in autociave.
3.2 Autoclaved aerated concrete products (AACP)
Autoclaved aerated concrete (3.1) is produced in the form of blocks or small slabs without reinforcing reinforcement bars, suitable for construction and installation of wall structures, partitions in construction works
3.3 Autoclaved aerated concrete block (AACB)
Autoclaved aerated concrete block products (3.2) have a predominantly rectangular horizontal cross-section with a width less than a negligible length (see Image 1A)
3.4 Autoclaved aerated concrete slab (AACS)
Autoclaved aerated concrete slab products have horizontal cross section of rectangles in which a width is smaller than the length (see Image 1B).
3.5 Product moisture content prior to shiping
The moisture content of autoclaved aerated concrete products (3.2) at the time of shipment out of the factory to the construction site.
Accordingly, in subsection 3.2 Section 3 National Standard TCVN 7959: 2017, autoclaved aerated concrete products (AACP) are defined as follows:
Autoclaved aerated concrete (3.1) is produced in the form of blocks or small slabs without reinforcing reinforcement bars, suitable for the construction and installation of wall structures, and partitions in construction works.
In Section 6 National Standard TCVN 7959: 2017, technical requirements for autoclaved aerated concrete products are specified as follows:
* Size deviation according to Table 2
* Bonding defects according to Table 3
* Compressive strength and dry volumetric mass according to Table 4
* Shrinkage not greater than 0.02% (0.2 mm/m)
* The moisture content prior to shiping of autoclaved aerated concrete products is not more than 25% for products using high silicon oxide materials from sand and not more than 30% for products using high silicon oxide materials from fly ash. The manufacturer provides this indicator at the request of the buyer.
What are the regulations on shapes, dimensions, and conventional symbols for autoclaved aerated concrete products in Vietnam?
In Section 5 National Standard TCVN 7959: 2017, shapes, dimensions and conventional symbols for autoclaved aerated concrete products in Vietnam are specified:
* Shape
For autoclaved aerated concrete block ar slap products - see Image 1, the head surface (6) can be flat or convex and concave for locking when masonry and fitting.
* Basic dimension
Autoclaved aerated concrete products have basic dimensions as shown in Table 1.
Note: autoclaved aerated concrete products of different shapes and dimensions can be produced at the request of the buyer.
* Conventional symbols
The conventional symbols for autoclaved aerated concrete products are shown in the following order of information:
- Product form; block form (AACB); slap form (AACS)
- Compressive strength grade.
- Dry volumetric mass group;
- Order of size by length, width and height;
- cite this standard.
Example:
1 autoclaved aerated concrete block product (AACB) has compressive strength B 3, dry volume 500 kg/m3, length 600 mm wide 200 mm and height 300 mm, with the following conventional symbols:
AACB 3 - 0500 - 600x200x300 TCVN 7959:2017
2 autoclaved aerated concrete slap products (AACS) have compressive strength B4, dry volume 600 kg/m3, length 1500 mm, width 200 mm and height 600 mm. There are conventional symbols as follows:
AACS 4 - D600 - 1500x200x600 TCVN 7959:2017
What are the regulations on labeling, storage, and transportation of autoclaved aerated concrete products in Vietnam?
In Section 8, National Standard TCVN 7959: 2017, labeling, storage, and transportation of autoclaved aerated concrete products in Vietnam are specified as follows:
* Labeling
On the two symmetrical sides of the pallet of autoclaved aerated concrete products are glued or inscribed with indelible ink information about the product, which states:
- Abbreviated name and address of the production facility.
- Conventional notation (as per 5.3).
- May of production and shipment.
- Compressive strength grade.
- Dry volumetric mass group.
- Other product features (upon request)
- Invoke this standard.
* Storage, transportation
Autoclaved aerated concrete products are stacked on pallets and tightened with PVC wire or other suitable material. autoclaved aerated concrete pallets are stored according to each type, in a sheltered place, ensuring dryness, no exposure to wet environments, and impacts that cause chipping or affect quality.
Autoclaved aerated concrete products are transported by appropriate vehicles, ensuring no wetting and impacts that cause chipping or affect quality.
LawNet