Field investigation of engineering properties and uniformity of subgrades chemically treated with LKD

A field investigation was performed immediately after the construction of a subgrade treated with 5% lime kiln dust (LKD) to determine the degree of uniformity and quality achieved using current construction techniques. A 280-m long section of a road was chosen for the field tests. The first 140 m was treated with LKD over a target thickness of 41 cm (16 inches), which is the current standard practice in Indiana. The second 140 m was treated with a reduced target thickness of 36-cm (14 inches). For the thicker, 41-cm treated subgrade, the increase in california bearing ratio (CBR) with respect to that of the untreated soil at the site was around 100%, as average, while for the thinner, 36-cm treated subgrade it was about 350%. All field and laboratory test results showed consistently better and more uniform results for the 36-cm thick treated subgrade than for the 41-cm thick treated subgrade.