<p><p><h2>Commentary</h2>Waste materials are typically incorporated into a highway reconstruction project in one of the following ways:<br><ul> <li>Modification of unstable soils</li> <li>Embankment materials</li> <li>Slope stabilization</li> <li>Supplementary cementitious materials for Portland cement concrete mixtures</li> <li>Slag aggregates used in subbases</li> <li>Slag aggregates used in portland cement concrete mixtures</li> <li>Bottom ash used as embankment material</li></ul>Because waste materials are components of a contract pay item, the associated cost of reusing waste materials is difficult to discern from historical bid tabulations.</p><p>In general, specifications should allow the use of waste materials, but not force their use. This allows market forces to determine the most cost effective and sustainable use of waste materials. Both the availability of alternative materials and the demand from alternative use markets for waste materials have a large influence on project costs savings that are passed on to the owner and make them difficult to quantify.<br><h2>Cost Information Summary</h2>The following items should be considered when estimating the costs associated with the use of waste materials:<br><ul> <li>Material cost</li> <li>Freight cost</li> <li>Is specialized equipment required for material handling?</li> <li>Environmental impacts</li> <li>Long term performance</li></ul><h2>Conceptual Cost Estimating Tool</h2>No cost estimating tool is provided for this technology. The potential uses of waste materials are too many and too varied to provide a simplified cost estimating tool.</p></p>