Title: Method for Preparing SR-4 Strain Gages for Embedment in Concrete

Author(s): Edward C. Thoma and Robert E. Schneebeli

Publication: Journal Proceedings

Volume: 49

Issue: 12

Appears on pages(s): 305-316

Keywords: no keywords

DOI: 10.14359/11821

Date: 12/1/1952

Abstract:
It has long been appreciated that analysis of concrete structures might be improved if a suitable means could be established for determining the behavior in the interior of a concrete mass. The very nature of its manufacture produces a heterogenous material, thereby invalidating the assumption of homogeniety which can be applied with reasonable truth in developing theo-retical analysis of most engineering materials. Aggregate distribution within the mass, gradation, maximum particle size, and other variables influence the behavior of a concrete structure. This paper presents a procedure for preparing and installing the SR-4 wire resistance strain gage within a concrete mass for the purpose of determining the behavior in the interior. Controlled laboratory studies of the gage unit itself, as well at gage units embedded in mortar and concrete, are reported to establish the reliability of the prepared SR-4 gage. In addition, preliminary studies of a field application, namely a highway slab installation, are included once they further establish the practicality and long-range reliability of the gage under severe test conditions.