Science Buddies: "Ask an Expert"

hi,

My name is trang dang i have quesiton about my project. Why does some construct workers would rebuild the road again? What is the problem of the road? What does the road do to effect the environment around us? How long does it take to paved the road?


Thank you very much,
Trang Dang :D

Repaving concrete roads is sometimes necessary. During the summer, when temperature is high, concrete roads tend to expand. On the other hand, during the winter, temperature is lower, roads tend to shrink (or contract). The result of that is growing cracks on the road or became uneven and sometimes construction workers must repave the entire road to fix the problem. Of course, when the roads are old, there's a wear and tear effect too.

Safety is probably the biggest concern when it comes to repaving roads. Severe uneven and cracked roads can cause car accidents.

Repaving roads involves a few layers of laying down concrete and letting each layer to dry. Roughly speaking, each layer of concrete should be able to dry overnight.

Hope this helps. Let me know if you have any more questions.