Raised pavement marker are very popular around the world, especially in the United States. Let us see why it is so popular in the United States. What is the difference between China and the United States for their detection methods?
In the United States, the applicable standard for reflective road studs is ASTM D4280. To a large extent, we have already referred to ASTM 4280 when formulating the standard. In some terms, the standard should be higher than that of the United States. For example, due to the serious overloading of vehicles in China, the requirements for road studs' compression resistance are higher than that of the United States. Moreover, the revision of domestic road studs' standard keeps pace with the times, and has basically been practical and realistic and the issue of standards is not an important one.
There are three types of testing methods in China:
a.For sample testing, only responsible for samples;
b.For batch inspection,only responsible for the quality of the batch;
c.Check the factory to see if there are machines and equipment, if there is a perfect system, and
issue a batch production license.
There are two ways of testing in the United States:
a.For sample testing, only responsible for samples;This is almost the same as China.
b.Field Testing,this point is different from China, and it is also a key point of this paper.
The first is the selection of experimental standard road section, which has the following conditions:
1> The road is free to pass;
2> During the inspection, no maintenance construction will be carried out for the road surface with raised pavement marker.
3> The traffic flow is 35000 times, and then the specified number of reflective road studs are installed on it.
Outdoor observation:the reflective road studs are installed on the road for two years and observed once every half a year, and the observation results are divided into five grades:
1.Excellent, completeas new;
2.Very good, with small scratches;
3.Medium, with obvious defects, but it can also play a role;
4.Bad, seriously damaged, weak effect;
5.It's bad. It doesn't work at all.Then test its luminous intensity.
Presentation,An observation report shall be issued once a year, and a final report shall be issued two years later,
and then the report shall be submitted to the government. The report shall include the following contents:raised pavement marker photos;Average vehicle flow at the test site;Proportion of large trucks;Rainy day data;Data at
high and low temperature;Laboratory data;Comprehensive description of laboratory;Binder type and Outdoor observation data.