You can apply in person at any of the following plants. 

Transit Mix Concrete - Main Office and Johnson City Plant
110 City Garage Rd, PO Box 1275
Johnson City, TN 37605-1275

Transit Mix Concrete - Kingsport Plant
1111 E. Industry Dr.
Kingsport, TN  37660

Transit Mix Concrete - Bristol Plant
496 Washington St.
Bristol, VA 24201

You can print out the Preliminary Application for Employment and mail it to
     Employment Opportunities
     PO Box 1275
     Johnson City TN 37605-1275
along with a photo copy of your current drivers license.