Improving stability of low-volume forest roads using a lignin-based emulsion
Unitol DKG, a lignin-based emulsion used to stabilize road surfaces was tested on a low-volume forest road near Chapman, Alabama. Two replicates of three treatments were applied during October 1999 that included a 3:l dilution of Unitol DKG, a 6: 1 dilution, and pack & grade with no chemical. Also, two control sections were located at each end of the test area. California Bearing Ratio (CBR) and moisture content were measured the following November and March. In addition, soils treated with three different dilutions of the product were subjected to Unconfined Compression (UC) and CBR tests in a lab. Adding the Unitol appeared to bind the soil together. Strength appeared to develop with time in treated road sections. The field CBR's consistently increased from November to March for the chemically stabilized and pack & grade sections. The 3: 1 dilution had the best strength performance in the field tests, while the 6: 1 dilution was not much different from the control sections. There was not a significant difference in the performance of the various dilutions in the UC tests. The UC tests showed increased plasticity at the lower dilutions. The saturated lab CBR tests showed that the 3:l dilution retained its cohesiveness under wetted conditions. The lab CBR tests showed higher strength in the weaker dilutions than in the 3:1.