Over time, Thang Long Bridge has deteriorated many times. Until now, the bridge has undergone several major repairs and numerous minor repairs, with costs totaling hundreds of billion dong. In the 1999 major repair, the construction unit removed the top layer and applied a new layer of concrete. In 2009, the surface of Thang Long Bridge was replaced with a coating using SMA technology. However, after just 2 months, the bridge surface was damaged and had to undergo major repairs in 2011-2012. Most recently, in August 2020, a large-scale project to repair the surface of Thang Long Bridge was commenced with a total investment of nearly 270 billion VND. In this 3rd major repair, the bridge surface was completely stripped, including the concrete layer and adhesive layer, and then a new surface was applied using the latest technology.