Problems in anticorrosive wood engineering
All kinds of anticorrosive wood engineering can be seen everywhere in China, most of them are urban construction projects or municipal beautification projects. But if you go into the park near the community and observe the plank road in the scenic area carefully, you will find that most of the anticorrosive wood engineering is purely vase and bean curd dregs engineering, and cracking, decay, fracture, blackening and other problems are very common. Originally, the use of anticorrosive wood for outdoor floor and guardrail is to prevent water, corrosion, moisture, mildew, insects, etc., but why there are all kinds of problems? This will start with what is antiseptic wood
Problems in anticorrosive wood engineering
What is antiseptic wood?
Preservative wood is mainly to add chemical preservatives to ordinary wood, so that the wood has the characteristics of anti-corrosion, moisture-proof, fungi, insects, ants, mildew and water-proof.
Preservative wood is generally made of water-based preservative that is not soluble. The preservative is put into the wood fiber while the pressure is applied to the wood in a closed vacuum tank. According to the types, there are mainly CCA antiseptic wood and ACQ antiseptic wood.
1. CCA is chromized copper arsenate, and its main components are copper, chromium and arsenic. Chromium and arsenic are harmful substances of heavy metals, especially arsenic, commonly known as "arsenic", which are highly toxic. As the loss rate of chromium and arsenic in CCA preservative wood is more than 40%, it will cause potential harm to water, environment and human body. If the human body touches the preservatives lost from CCA preservative wood, it should be cleaned immediately, otherwise, there is a great potential danger to children. For example, the chromium and arsenic contents in the soil and water sources near the CCA anticorrosive wood pavement will be significantly higher, and such heavy metals will migrate to crops and animals, and if they are finally eaten by human beings, they will finally migrate to the human body.
2. ACQ is the abbreviation of quaternary ammonium copper. Its main components are copper oxide and quaternary ammonium salt. Although it does not contain chromium and arsenic, its main disadvantage is that it is unstable and easy to lose. Moreover, ACQ preservative wood used in China is imported from Nordic countries after treatment. For example, Finland's antiseptic wood is ACQ treated, so ACQ antiseptic wood is also known as "Finnish wood", but its price is expensive. Generally, the antiseptic wood used is CCA antiseptic wood.
No matter what kind of antiseptic wood is attached to the surface of chemical preservative, with the loss of preservative and the moisture content of wood itself, it will deform, discolor, blacken, crack or even rot after being exposed to the sun and rain. Therefore, in the follow-up use, wax oil and other surface treatment agent for maintenance, maintenance, maintenance cost is high.
It can be understood that preservative wood is not wood that will never rot, but through post-treatment and regular maintenance to delay all kinds of wood problems.
However, most domestic anticorrosive wood projects are public construction projects, and the contractors basically give up after installation. Generally, there is no post-sale link. There are two reasons behind this: on the one hand, anticorrosive wood needs to be maintained regularly every year, and the cost of regular maintenance and replacement is much more expensive than that of anticorrosive wood materials, some of which are even several times as high as the original bidding price, Naturally, the contractor will not give any additional maintenance fee; On the other hand, anticorrosive wood without regular maintenance is no different from ordinary wood. Basically, it needs to be demolished and replaced in one to three years. In this way, the basic project has to be re tendered for construction, which will involve a lot of interest relations. Of course, the contractor is willing to take advantage of it.
If you travel to Europe and the United States and other countries, you will find that anticorrosive wood is rarely seen in European and American countries. Outdoor swimming pools, hotel outdoor floors, villas and other basic use high-quality wood plastic materials. Antiseptic wood has long been eliminated by the market.
The new wood plastic composite material is a kind of new material which can be recycled by using low value or waste plastic, sawdust, straw and other main raw materials, using the polymer interface chemistry principle and the characteristics of plastic filling and modification, mixing a certain proportion of plastic base material, after pretreatment and professional process treatment, processing and forming a new material that can be recycled. The new wood plastic material is not only moisture-proof and waterproof, but also can fundamentally solve the problem that wood products are easy to rot, expand and deform due to water absorption and damp in humid and watery environment. Moreover, it can prevent mildew, termite, acid and alkali resistance, corrosion resistance, formaldehyde free, recyclable and recyclable. At the same time, it has strong plasticity and can be customized and installed by fool, At present, it has become the mainstream substitute wood in developed countries.
There is another reason why anticorrosive wood engineering is relatively common in China. The 2008 Beijing Olympic Games and Shanghai World Expo have promoted the application of wood plastic materials in China, but at the same time, many small wood plastic factories with poor quality have been attracted to make quick money. They do not pay attention to the product quality, and copy the appearance and put them into the market. Because most of the domestic projects are won at low prices, good wood plastic enterprises such as Helong wood plastic mainly export to Europe and the United States, and are basically monopolized by small wood and plastic manufacturers. As a result, a lot of domestic wood plastic projects have a very bad reputation after being applied, and consumers feel cheated, which has a great negative impact on the whole wood plastic industry.