ABSTRACT
Infrastructure constitutes a large investment; it is important to strengthen the transportation network to enhance the country’s economy and the standard of living for its residents. With the continuous development of infrastructure, road tunnels have become essential to avoid longer routes, preserve land resources and provide uninterrupted access through urban areas and physical obstacles such as existing roads and mountains, which promote sustainability and enhance transport efficiency. Asphalt and concrete are the two competitive materials that can be used to build tunnel roads. However, the concrete’s incombustible and non-toxic nature contributes to a safer tunnel environment. Furthermore, concrete roads are more wear-resistant, have a longer service life and require less maintenance during their lifetime, while the concrete bright colour contributes to minimising electric energy consumption for lighting. This paper aims to provide a comprehensive overview of the tunnel roads, highlights the key characteristics of concrete and presents a state-of-the-art review of tunnel concrete roads.
