Causes of steel corrosion in concrete

Posted on

The construction wave is surging all over the country. Buying a house for living or investing has become a major expense in people's lives. There are more and more complaints and disputes about the quality of the house. These complaints are still some of what we can see. Problems, some unseen problems often cause more serious consequences.

As we all know, the life of a building needs to be guaranteed based on a series of technical indicators, which includes both theoretical support and design requirements, and is more dependent on the guarantee of construction materials and methods. At present, the design life of conventional houses in China is 50 years. This kind of life prediction is based on the concrete design codes of our country, although it is not a very high standard. (Foreign house life estimates can reach 80 years, some (Even more than 100 years), but many houses in our country can't even meet such a low standard. Due to the problem of building structure, the life of many reinforced concrete is only about 25 years, which is the main reason for this "life failure" situation. One of them is the corrosion of steel bars.
In a building, the combination of steel and concrete is the skeleton that supports the whole body weight. The steel meets water in the air, plus some "impurities" in the steel material, so it is easy to rust. In order to avoid this in concrete When this happens, a concrete protective layer should be added outside. The “Code for Design of Concrete Structures” (GB50010-2002) clearly stipulates the minimum protective layer thickness of concrete with reinforced steel bars with a design service life of 50 years in the construction regulations; for example: in a normal indoor environment, the concrete strength level is The minimum protective layer thickness of concrete, walls, shells and concrete between C25-C45 is 15 mm; beams are 25 mm; columns are 30 mm. In other words, only when the concrete wrapped around the steel bar is not less than the specified thickness, the steel bar will begin to corrode after 50 years. If the thickness of the protective layer is insufficient, the steel bars inside will rust in advance.
In the past, due to insufficient understanding of the protective layer of steel bars, there was generally a lack of attention in construction. For example, the use of homemade mortar pads to control the thickness of the protective layer is a method commonly used by construction units in the past: make some mortar with different thickness requirements before construction After the steel bar is tied, the pad is tied or tied to the steel bar to control the thickness of the protective layer, but there are many problems in doing so. First, the thickness of the mortar block is uneven and the strength is relatively low. It is very easy to run when tied to the standing bar and the template It was crushed and sometimes the concrete underneath the transverse ribs was crushed before pouring, which did not play a role in controlling the protective layer; most construction units now use plastic cassette pads, although there is a slight increase in construction costs However, it can basically effectively control the thickness of the protective layer, which plays an important role in improving the service life of the building.

Keep invoices, packing lists and shipping orders protected and securely attached to boxes and other containers throughout the shipping process

Crafted from oil- and water-resistant polyethylene with a high-tack rubber resin adhesive, our packing list envelopes are built to withstand some of the toughest handling conditions.

Available with or without printing in a variety of sizes to match your individual shipping needs. To keep shipping labels safe and secure, we also offer both clear and high visibility label protection tapes.

printed/unprinted, clear/white, side-loaded /top loading polyethylene envelope with easy and secure open and close. We designed this envelope with a high-tack rubber resin adhesive that sticks on contact to packages. Oil- and water-resistant, this Packing List Envelope securely protects documents from damage throughout delivery.
  • side-loaded/ top-loaded envelope opens easily and closes securely
  • Provides control and protection of on-package packing list and invoice documents
  • Non-printed/printed  design provides a clear window for logos, instructions or other information and is barcode readable
  • Offers convenient peel-and-stick document attachment
  • Features a polyethylene backing, synthetic rubber adhesive and paper liner
  • Tough film helps reduce puncturing and tearing


Customized Products

Logistics Packaging,Packing List Envelope,Express Packaging, Courrier Packaging, Packing List Pouch, Packing list enclosed

AM-Besten Technology Ltd. , https://www.bestenpack.com