How to calculate the dowel sleeve

The dowel bar refers to the round steel bars arranged in the middle of the slab thickness every certain distance along the transverse joint of the cement concrete pavement. One end is fixed in one side plate, and the other end can slide in the adjacent side plate. Its function is to transfer traffic load between two road slabs and prevent platform staggering, increase stress transfer between adjacent concrete blocks, so as to prevent uneven settlement of concrete pavement caused by large local stress on concrete pavement, and transfer stress to make adjacent concrete blocks bear stress together

the equipment is also used to detect 23 joints of two cement pavement sections in Illinois, USA. here, the evaluation standard of this paper is used to summarize the joint dowel deviation of North Hei Expressway and Illinois, USA. The following conclusions can be drawn from the comparison:

(1) compared with foreign high-quality construction level, DBI construction technology is still in its infancy in China, and the dowel bar deviation control technology needs to be improved

(2) the horizontal movement deviation leads to the unacceptable level of the dowel bar, which is 0% in the United States and 1.8% in the North black highway, indicating that the horizontal movement deviation can be well controlled by DBI process

(3) the longitudinal movement deviation leads to the unacceptable level of the dowel bar, which is 1.1% and 5.6% respectively in the United States and North black highway, and the proportion between the unacceptable level and the acceptable level is 12.4% and 29.3% respectively. The longitudinal movement of the dowel bar is closely related to the position of the slit

Right, because watching movies or mobile phones for a long time will lead to a kind of damage to our brain nerves, which will lead to our distraction. After a long time, there will be some damage to our brain, and our attention will not be able to concentrate{ RRRRR}

What's the reason for children's inattention? Does frequent use of electronic procts affect attention? It mainly includes the following points:

1, forcing children to do things they don't like

many times, parents will think that their children are good, relying on their years of experience, forcing their children to do things they don't like, such as asking their children to complete a book they don't like, reporting training courses they are not interested in, There are many unnecessary regulations on children's daily behavior. In the long run, children's seriousness and concentration will decline, and even they will not have their own ideas. As the saying goes, interest is the best teacher. If you want to cultivate children's ability, you can start from making them interested, otherwise it is likely to be the opposite

2. It's easy to use electronic procts to kill children

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it's opposite to the first kind of parents' ecation mode. This kind of parents completely let their children develop freely. They not only lack conscious attention training, but also directly use mobile phones and iPads to kill their children when they are interested in and curious about things, Such a learning environment will naturally rece children's desire to explore knowledge, and they are easy to inlge in electronic procts. As a result, they are very focused when playing with mobile phones and are on pins and needles when doing other things

3. When children are very focused, parents interfere or disturb them.

some children's learning attitude and attention are very good, but they are interfered and disturbed by their parents for a long time, which leads to that the ability of concentration can not be fully developed. For example, when children are focusing on learning and doing homework, it is also regarded as a simple process of attention training, and parents often ask questions, Or they are afraid that their children will work hard to bring in food or fruit. By the way, they will interrupt their complete thinking, which is not concive to the cultivation of the breadth and stability of their concentration, and they will not be able to concentrate for a long time

playing with mobile phones often can cause certain damage to the brain, which is reflected in two aspects it has an impact on the speed of our brain reaction, the concentration of our thinking, and the structure of our brain itself, thus affecting the health level of our brain{ RRRRR}