Determination of Optimum Moisture Content As Related to Creosote Intake Rate as well as Penetration Depth in Beech - Cross Ties

The service- life of railway impregnated cross-ties in Iran is much . lower than indicated . in the
International Standards. In this connection, some researchers believe that the moisture content of the timbers are not optimal prior to the treatment process. Therefore, the present study was conducted to study three different MC levels (12, 23, and 51%) to compare creosote retention as well as its peneteration in impregnated samples, using Bethel method. Results show -. that there is no significant difference between 12 and %23 (below FSP) •-Moisture _levels. Therefore that would be enough to decrease the MC to about %23 to insure the timbers would be properly impregnated with creosote, that is, there is no need to season the timber to as .low as %12 MC. This would facilitate and simplify treatment process as well as increase the service life of the impregnated timbers, including those used in railway -crass-ties.