*Maintaining the Sustainability of Critical Infrastructure DOI: http://dx.doi.org/10.5772/intechopen.85915*

*Infrastructure Management and Construction*

this defeats the purpose of sustainable development.

opportunities promotes sustainable development.

*U.S. apparent consumption of raw materials (courtesy of USGS).*

developing the maintenance plan, the plant's manager suggests relocating the access road to the neighborhood nearby that has a low population can save the travel time for the trucks that supply the materials for the plant. The decision seems to make sense from the environmental aspect as it saves a few minutes of travel time and can potentially lead to a reduction in the pollution caused by the trucks in the long run. However, it will impact the people living in the small neighborhood on a daily basis. Therefore, if environmental protection is the sole criteria for making a sustainable decision the social and economic aspects of sustainability can be compromised, and

It is essential to establish equity in pursuing sustainability [23] Equality in sustainability can be defined as being impartial to the communities while making decisions that can impact the triple-bottom-line of sustainability in neighboring areas. Lopsided progress in sustainability programs by putting one community prior to another is in contrast with sustainability goals. Bearing in mind that tradeoffs are inherited in many decisions tied to development, the community facing the consequences of a decision may be different from the community that benefits from it. Keeping the balance between neighboring communities in benefiting from the

**2.4 Sustainable material allocation throughout the maintenance process**

Growing concerns about depletion or shortage of resources, in addition to increasing demands for more materials, explains the necessity of efficient resource allocation [24]. Depending on the type of infrastructure and the depth of the maintenance operations, the volume of required materials for the maintenance can vary from small amounts to enormous quantities. For example, tons of concrete can be required in the replacement of a bridge segment. The way these materials are selected, shipped, and used in the maintenance operations have impacts on the triple bottom lines of sustainability. According to the World Counts, on average everyone uses 16 kilos of resources extracted from the earth every day, and for people in the western world, this number is much higher—up to 57 kilos of newlymined minerals per day [25]. Based on the United States Geological Survey (USGC) the U.S. apparent consumption of raw materials at the beginning of the century has

**24**

**Figure 8.**

increased more than six times from 1940s (see **Figure 8**). The infrastructures are massive consumers of resources worldwide. For example, a total of approximately 1.5 billion tons of aggregates, 35 million tons of asphalt, 48 million tons of cement, and 6 million tons of steel is in place in interstate highways of the USA [25].

In addition to the depletion of resources, transportation and shipping of raw materials can affect the environment in multiple direct or indirect ways. The massive amount of construction materials that were mentioned in the example above must be transported to sites through thousands of trips by heavy equipment that contributes to air, water, and noise pollution as well as fuel consumption. The indirect effects of trips to supply the materials for the infrastructure can indirectly contribute to global warming, climate change, and threaten the health of human beings. Additionally, continuous traffic of heavy equipment to an infrastructure (such as plants and refineries) will have impacts of the property value of the surrounding neighborhoods and affect the economy bottom-line of sustainability.

These examples indicate that any improvement in the way the infrastructure materials are procured is expected to significantly contribute to sustainable development.
