Title: Construction Tolerances in Reinforced Concrete Beams/Joists

Author(s): Joesph P. Connolly

Publication: Journal Proceedings

Volume: 73

Issue: 11

Appears on pages(s): 613-617

Keywords: beams (supports): calibrating: computers:covers: embedment: joists; nondestructive tests; pachometers:probability theory: reinforced concrete: reinforcing steels: standard deviation; statistical analysis; tolerances mechan-ics

DOI: 10.14359/11101

Date: 11/1/1976

Abstract:
This investigation was a pilot study to develop the technique for nondestructive measurement of variations in depth, width, and location of reinforcing steel in existing reinforced concrete beams and joists of 8 in. (20.3 cm) or greater depth. Data were collected on beams and joists chosen from five structures by both optical and electronic measuring devices. Statistical evaluation of this data is presented as well as a computer analysis of the approximate effect of such variations on the strangth of the sections. The study proves the technique and gives bounds to the problem, and as such is not all-encompassing. Further study is shown to be a necessity, as the results reveal that current as-built structures normally exceed the design-assumed tolerances.