Project Description:

Decarbonizing transportation infrastructure is one of the primary goals of the US DOT. This project aims at decarbonizing transportation infrastructure by reducing the cement usage during its construction and maintenance. For this purpose, agricultural residues (corn stover and wheat straw) with reactive silica are considered as an excellent replacement due to their wide availability in the US and reduced environmental footprint. This is because the combustion temperature for agricultural residues is significantly lower compared to the temperature required for cement clinker production. However, agricultural residues need to be pre-treated properly to be used as an effective source of replacement for cement. Although previous studies have showed that pre-treatment improves the reactivity, a framework for obtaining consistent quality of residual ashes is still missing. In this project the primary goal is to achieve such a framework that can be used to boost the reactivity and consistency of residual ashes. Figure 1 envisages the process that will be developed in the project. 

_{Figure 1. Converting Agricultural Ash to SCMs}

US DOT Priorities:

This project supports one of the primary strategic goals of USDOT (i.e. climate and sustainability). The primary thrust area lies in preserving the environment by producing environmentally responsible construction material.  Construction and maintenance of transportation infrastructure is one of the major contributors to the release of global warming gases (especially CO2) due to the production of cement. Therefore, replacement of cement with agricultural residual ashes which has reduced environmental footprint will lower the production of cement. This project will provide a framework to boost the production of reactive and consistent quality of sustainable construction materials from agricultural residues thereby, preserving the environment.

Outputs:

Major challenge of using agricultural residues as an alternative SCM is the lack of consistent quality due to change in source. This project is devised to address the above challenge. Following will be the output of the project.

1. Scientific understanding towards pre-treatment methods and the mechanism behind removal of impurities from the agricultural residues. 
2. A pre-treatment framework based on empirical model that can be used to obtain consistent quality of the agriculture residual ashes.
3. Scientific understanding towards the reactivity and hydration mechanism on the usage of pre-treated and calcined agricultural ashes.
4. A life cycle analysis model that can be used to assess the cost and impact on choosing a particular pre-treatment method.

Outcomes/Impacts:

This project will have the following outcomes.

• This project will enable and enhance sustainable use of agricultural residues as an alternative SCM. By doing so, the impact of transportation infrastructure on the climate can be reduced. 
• Life cycle framework that can be used to choose between different pre-treatment methods based on the cost and environmental impact.

The research finding will be given through publications, conference proceedings, seminar, and workshop presentations, etc. With the help from local government and DOT, a pioneer project will be found for the field application of this new material, which can be used as a testing bed for long-term monitoring and data collection for its life cycle analysis.