Many modern bridges use orthotropic steel bridge decks (OSBD), the decks being the surface sections of the bridge. OSBDs were designed to be lightweight and economical. However, this design has shown increasing issues with pavement cracking and fatigue damage at the welds that connect the bridge deck to the bridge superstructure. Fatigue damage is damage that accrues over time with use.

To ameliorate these problems, a new bridge deck was designed. The composite bridge deck system (CBD) added a layer of concrete to decrease the probability of damage due to fatigue. More recently, the use of high-performance materials, such as ultra-high-performance concrete (UHPC) and engineering cementitious composites (ECC), have been incorporated into the CBD design.

Chinese scientists recently reviewed current research on the performance and durability of these two types of bridge deck designs and the effect of incorporating the new high-performance materials into the design of the newer CBD.

"Both new and traditional bridge deck systems possess distinct advantages and disadvantages, indicating their suitability for various application scenarios. A comprehensive review of these bridge deck systems can provide scholars and engineers with a deeper understanding and facilitate their effective application," said Jingzhong Tong, a researcher at the Institute of Advanced Engineering Structures.

Their review was published on April 29 in Intelligent Construction.

The researchers reviewed studies on the traditional orthotropic steel bridge deck systems, along with the newer composite bridge deck system which used one of three different materials: the original steel- concrete, and two high-performance materials, steel- UHPC and steel-ECC. UHPC and ECC are cementitious composites with properties that are very useful in bridges.

UHPC has ultra-high compressive strength, allowing for the use of thinner slabs with greater bending strength and greater stiffness than regular concrete. It is therefore easier to build with and does a better job under stress. ECC is very tough and highly resistant to cracking.

The studies they reviewed used different measures of bridge deck fitness. Examples of the types of measurements used in the papers included a bridge deck's flexural behavior, which is how the materials and design of the bridge deck react to loads that may cause bending, the fatigue behavior of critical welds on the bridge deck and the durability of the pavements, among many other factors.

The review found that fatigue performance was the greatest issue in the OSBD, and that the CBD design had comparatively greater fatigue resistance and sectional stiffness, which would be useful in long span bridges. When the UHPC was used in the CBD design instead of the steel-concrete, it increased the bridge decks' flexural performance. ECC use improved the bridge decks' crack resistance.

"The integration of these advanced cementitious composites into bridge deck systems significantly enhances their mechanical properties and durability, thereby mitigating the high maintenance costs associated with repetitive damage," said Yunlong Chen, the paper's first author and a scientist at Zhejiang University.

More information: Yunlong Chen et al, Application of high-performance cementitious composites in steel–concrete composite bridge deck systems: A review, Journal of Intelligent Construction (2024). DOI: 10.26599/JIC.2024.9180012

Provided by Tsinghua University Press