Paving stone of "70-year durability" in Hanoi already broke after few years
Natural stone used to pave the sidewalks of some streets in Hanoi has been committed to durability after 70 years of use. However, the actual use so far after only 3-4 years has been damaged or cracked, resulting a huge amount of waste both financially and environmentally.
According to Mr. Phong, each district is responsible for approving the project. The Urban Management Department is responsible for managing the quality of streets paved with pavement.
Regarding the phenomenon of the broken and damaged pavement stones, which has been reported by the press recently, according to Mr. Phong, mainly roads were paved with sidewalks before the issuance of Decision No. 1303/QD-UBND dated 21 March 2019 on "designing urban street summer models in Hanoi city". Mr. Phong said that the paving stone before this period was mined by blasting method, so the stone was braised. In addition, marble often has stone veins, is not homogenous, so when it rains, it expands, breaks itself, even without any physical impact. Moreover, the Director of the Department of Construction also said, "The stone is mined by blasting method, so the stone is brooded". It is not clear what it is meant by "brooding" stone, but in fact, most quarries are exploited by blasting method, not only for Hanoi pavement, and most of them still remain a long life-time.
However, most people do not agree with this explanation. The reason for the above situation is that the construction has not met the technical requirements, especially the quality of the concrete base layer. Furthermore, the inspection and acceptance of pavement paving quality is not high enough, especially with the amount of traffic driving on the pavement during traffic jam or the amount of parked vehicles throughout the days, the quality of the pavement could be challenged greatly.
In order to overcome the situation of pavement paving stones being dislodged, cracked, broken as mentioned above, the Hanoi People's Committee has assigned the Department of Construction to inspect, review and carefully evaluate the causes of the stone condition.
Source: the Internet