Soil Burial Tests: Effect of Soil Burial Exposure on the Properties of Structural Grade Reinforced Plastic Laminates

The effects of long-term soil burial on reinforced plastic is of major significance because of their present and projected use in intimate soil contact. Reinforced plastic manholes structures are two examples of projected uses that depend application of these soil burial data. 51 laminates increased and pipe upon the 52 II. T H E BELL S Y S T E M TECHNICAL JOURNAL, JANUARY 1972 CHEMISTRY OF R E I N F O R C E D PLASTIC LAMINATES Laminates discussed herein are made of two or more layers of reinforcement with a resin matrix. The physical, mechanical, chemical, and electrical properties of the resultant laminate are dependent upon the selection of the proper reinforcement, resin system, and fabrication method. 2.1 Resins This paper concerns itself with laminates made of polyester and epoxy resin matrices. 2.1.1 Polyester Resins Polyester resins are polycondensation products of a polycarboxylic acid and a polyhydroxy alcohol. These polyesters can be characterized as possessing a number of ester groups ( - C - 0 - ) and ethylenic groups i i O 1 1