Standards Development

Scope

This International Standard is applicable to the design and construction of reinforced concrete box culverts under the following conditions:

(1) Top slab of the culvert only bears highway vehicle loads, excluding heavy-duty traffic loads such as railway;

(2) The culvert is a inlet unsubmerged culvert, which means the water flow maintains a free surface state throughout the culvert, and there is no water pressure act on the culvert’s top slab;

(3) The single span of the box culvert does not exceed 5 meters.

The standard contains a complete technical regulations for box culvert engineering, including: standard configurations of box culverts, loads, material requirements, structural analysis model, bearing capacities, structural requirements, construction process and quality inspections. Through systematic technical regulations, this standard provides comprehensive technical guidance for box culvert projects meeting the above conditions throughout their entire life cycle.

Purpose

Reinforced concrete box culverts have gained extensive global application due to their advantages in structural reliability, cost-effectiveness, and environmental friendliness.

For the aspect of structural advantages, reinforced concrete box culverts demonstrate excellent structural integrity. A well-designed box culvert is stable and reliable, with high strength and good durability. Box culverts can be designed in various sizes, shapes, and angles to flexibly adapt to different on-site conditions and requirements.

In terms of economy, the simplicity of box culvert structures enables rapid construction and lower costs. In particular, for box culverts constructed by prefabricated construction method, factory-based manufacturing ensures weather-independent production, shortened construction cycles, and efficient on-site installation, which can significantly reduce labor costs and project periods. The service life of reinforced concrete box culverts is long, and the maintenance cost is low. In the long run, it can significantly reduce the total life cycle cost of the project.

Environmentally, box culvert construction minimizes large-scale earthworks, effectively reducing soil erosion. The adoption of prefabricated construction method further mitigates on-site noise, dust, and greenhouse gas emissions.

Globally, many nations remain in a critical phase of infrastructure development. With the acceleration of urbanization and population growth, the demand for infrastructure construction continues to increase. Box culverts have become essential components in infrastructure construction and are widely used in engineering projects due to the advantages mentioned above. Therefore, box culverts have a broad application demand worldwide.

In the international arena, some countries and regions have already established relevant standards. There are Chinese standard “Specifications for design of highway culverts”, the U.S. standard “AASHTO LRFD Bridge Design Specifications”, British standard “Precast concrete products — Box culverts”, and Australian standard “Precast reinforced concrete box culverts”. However, at present, there are still some areas still lack comprehensive design and construction standards. Some of them may refer to the standards of the aforementioned countries. The absence of a relevant standard system not only hinders the promotion and application of box culverts in these areas but may also lead to safety hazards and inconsistent quality in construction projects. Currently, ISO standards currently lack dedicated provisions for box culverts. Therefore, the purpose of this proposal is to provide safe, reliable, and practical design and construction guidelines for countries or regions that have not yet established relevant standards, while also further improving the ISO standard system for concrete structures.

Developing an international standard for reinforced concrete box culverts will bring multiple benefits to the global market. In terms of engineering quality, standardization would unify product specifications and facilitate global trade. Regarding technical collaboration, a unified criteria would promote international engineering cooperation, communication, collaborative innovation in technology, and industry advancement, thereby advance the sustainable development of global infrastructure construction.