<p><p><h2>Commentary</h2>Payment for injected light weight foam fill typically consists of a pay item measured by the pound (LB). Included in this bid item are associated incidental costs:<br><ul> <li>Drilling injection holes</li> <li>Sealing injection holes</li> <li>Instrumentation, monitoring and quality control</li></ul>Other costs associated with injected lightweight foam fill are measured and paid for separately:<br><ul> <li>Mobilization</li></ul><h2>Cost Information Summary</h2>The following table lists items associated with the cost of injected lightweight foam fill and approximate cost ranges. Cost ranges are based on data from 2009 through 2011. Readers should carefully examine the project characteristics and constraints and determine to what degree if any these factors may influence the actual cost associated with injected light weight foam fill.</p><p><table class='tablepress' id='tablepress-100'><thead><th>Pay Item Description</th><th>Quantity</th><th>Unit</th><th>Low Unit Price</th><th>High Unit Price</th><th>Factors Which May Potentially Impact Costs</th></thead><tbody><tr><td >Mobilization</td><td >1</td><td >LUMP SUM</td><td >$10,000</td><td >$20,000</td><td >Equipment mobilized includes drills, compressors, grout mixer and pump.

Mobilization cost increases for distances greater than 500 miles.

Phased projects may require multiple mobilizations
</td></tr><tr><td >Injected Lightweight Foam Fill</td><td >Greater than
1,000
</td><td >LB</td><td >$3.50</td><td >$8.00</td><td >Unit prices decrease as the volume of foam per hole increases</td></tr></tbody></table><h2>Historical Cost Information</h2>A sample of actual project costs is shown in the table below.</p><p><table class='tablepress' id='tablepress-99'><thead><th>Pay Item Description</th><th>Quantity</th><th>Unit</th><th>Low Unit Price</th><th>High Unit Price</th><th>Average Unit Price</th><th>No. of Bids</th><th>Bid Date</th><th>Source/Agency</th></thead><tbody><tr><td >Deep Foam Injection</td><td >37,800</td><td >LB</td><td >$4.50</td><td >$8.00</td><td >$6.82</td><td >16</td><td rowspan=2 >6/26/2009</td><td rowspan=2 >Arizona DOT</td></tr><tr><td >Polyurethane Grout Injection</td><td >3,100</td><td >LB</td><td >$4.50</td><td >$6.50</td><td >$5.40</td><td >7</td></tr><tr><td rowspan=2 >Roadway Stabilization with High Density Polyurethane</td><td >42,750</td><td >LB</td><td >$4.26</td><td >$6.50</td><td >$5.38</td><td >2</td><td >9/3/2010</td><td rowspan=2 >Michigan DOT</td></tr><tr><td >10,000</td><td >LB</td><td >$5.50</td><td >n/a</td><td >n/a</td><td >1</td><td >8/20/2009</td></tr><tr><td >High Density Polyurethane Foam</td><td >22,200</td><td >LB</td><td >$6.50</td><td >$7.85</td><td >$7.15</td><td >4</td><td >11/10/2009</td><td >South Carolina DOT</td></tr><tr><td rowspan=3 >Polyurethane Injection for Pavement</td><td >8,800</td><td >LB</td><td >$4.25</td><td >$5.14</td><td >$4.85</td><td >4</td><td >4/14/2011</td><td rowspan=3 >Oklahoma DOT</td></tr><tr><td >11,000</td><td >LB</td><td >$4.25</td><td >$4.95</td><td >$4.48</td><td >6</td><td >3/19/2009</td></tr><tr><td >16,000</td><td >LB</td><td >$4.25</td><td >$4.46</td><td >$4.32</td><td >3</td><td >3/24/2009</td></tr><tr><td rowspan=2 >Polyurethane (Mudjacking)</td><td >12,000</td><td >LB</td><td >$4.49</td><td >$4.85</td><td >$4.67</td><td >2</td><td >7/21/2010</td><td rowspan=2 >Kansas DOT</td></tr><tr><td >120,000</td><td >LB</td><td >$3.22</td><td >$5.19</td><td >$3.98</td><td >4</td><td >6/22/2011</td></tr></tbody></table><h2>Conceptual Cost Estimating</h2><ol> <li>Estimate the volume of voids to be filled with injected light weight foam</li> <li>Convert the volume to a mass - the density of polyurethane foam ranges from 100 kg/m³ (6.2 lb/ft³) to 300 kg/m³ (18.7 lb/ft³). The density of this material depends on the compression resistance of the surrounding soil to its expansion (<em>Brunate (2003). P. 3-5</em>)</li> <li>Multiply the mass of injected light weight foam fill by an estimated unit price</li></ol></p></p>