cement

After his son tragically died in an accident caused by a pothole, Dadarao Bilhore took it upon himself to fill potholes around Mumbai. Using sand, gravel, and cement collected from building sites, he has filled 600 potholes since 2015 and continues on. – WTF Fun Facts

Source: https://www.scmp.com/news/asia/south-asia/article/2164184/his-son-was-killed-mumbais-crumbling-roads-now-dadarao-bilhore