Introduction

Abstract

The aircraft and building construction industries are making widespread use of the structural sandwich panel, made possible through simultaneous developments in the structural adhesive and the light-weight core material fields. Considerable savings in weight, assembly time, and costs have been realized, with the added advantages of improved appearance and smoothness. From the inception of the ASTM Committee C-19 on Structural Sandwich Constructions in 1948, the main emphasis has been on development of standard test procedures so that sandwich material properties could be determined in a manner that would have the same meaning to everyone using the data. This has also been reflected in the two symposia sponsored by Committee C-19 in 1951 and 1956, the subject matter being—in the main —material properties, test methods, and design criteria. Although the emphasis in the beginning was on material properties and test methods, the problem of durability under environmental conditions was recognized early and resulted in the organization of subcommittee III on Permanence, Durability, and Simulated Service. In 1955 a series of exposure programs for sandwich panels was initiated at two ASTM exposure sites, Kure Beach, N. C., and State College, Pa. It was the completion of the first of these 3-yr programs that prompted the concept of this Symposium on Durability and Weathering of Structural Sandwich Constructions.