Recently, on the south bank connection line of the Hangzhou Bay Bridge, a piece of UHPC (ultra-high performance concrete) ribbed thin plate with a peculiar shape is closely attached to the old guardrail with the help of hoisting equipment, and is limited to the road surface groove, and the original rusty and low guardrail has completed the "reverse growth".
Hangzhou Bay Bridge South Bank Connecting Line was completed and opened to traffic in 2007, the bridge anti-collision guardrail adopts reinforced concrete guardrail, at present, part of the reinforced concrete anti-collision guardrail surface concrete aging and peeling, affecting the appearance of the road area. In order to continue to promote the upgrading of highway traffic safety facilities, Datong Company, a subsidiary of Ningbo Communications Investment Group, selected the guardrail of the south connection bridge of Hangzhou Bay Bridge as a pilot to carry out the upgrading and transformation of the old guardrail. At present, the conventional way to solve related problems in the industry is to dismantle the existing guardrail and then pour a new guardrail in situ, which has a large amount of engineering, a long construction period and a high potential safety hazard. Datong Company cooperates with relevant research institutes on the premise of not dismantling the existing guardrailsThe composite sandwich material of "prefabricated UHPC ribbed sheet + lightweight energy-absorbing material" is innovatively applied to reinforce and upgrade the existing guardrail. UHPC ribbed sheet has high compressive and tensile resistance, which can effectively resist local impact damage, and the filling material behind the plate can absorb impact energy, which improves the anti-collision ability, safety and construction convenience of the guardrail while completely retaining the existing guardrail. 
At present, the UHPC composite sandwich guardrail technology has successfully passed the real vehicle crash test and has been applied to the Andong test section, marking a new breakthrough in the existing guardrail lifting project in the special operating environment of the group's expressway. In the next step, Datong will fully promote the technology and complete the upgrading of the guardrail of the south line.