PROBLEMS OF HIGH STRENGTH BOLTED CONNECTIONS IN STEEL CONSTRUCTION. SUSTAINED LOADING TESTS

This report contains the results of investigations into the effect of prolonged static loading (sustained loading tests) on the coefficient of friction. Four groups of specimens were selected for the tests and their faying surfaces treated as described below (see Report D 90/No. 2, conclusions 3.7 and 3.8): (a) blast-cleaned with chilled iron grit, on surface protection; (b) sprayed aluminum coating; (c) sprayed alkaline silicate zinc dust paint; (d) sprayed zinc coating. All specimens were tested at a temperature of plus 20 degrees C, those with protected surfaces having also been tested at a temperature of plus 60 degrees C and minus 20 degrees C. The results show that none of the three protective coatings should be rejected solely as a result of its performance in the sustained loading tests. By comparison with the static tensile tests, the sustained loading tests gave less favorable results for certain types of protective coating. The tests have shown that the following coefficients of friction are justified: 0.66 for unprotected faying surfaces which have been blast-cleaned with chilled iron grit; 0.75 for faying surfaces protected by a sprayed aluminum coating; 0.45 for faying surfaces protected by a sprayed zinc coating; and 0.60 for faying surfaces protected by a coating of alkaline silicate zinc dust paint. No significant effect of extreme temperatures was found.

• Supplemental Notes:
  • Restrictions on the use of this document are contained in the explanatory material.
• Corporate Authors:

  International Union of Railways

  Office of Research and Experiments
  Utrecht,   Netherlands 
• Publication Date: 1969-10

Media Info

• Features: Figures; References; Tables;
• Pagination: 25 p.

Subject/Index Terms

• TRT Terms: Bolted joints; Bolts; Coefficient of friction; Construction joints; Corrosion protection; High strength; Protective coatings; Steel structures; Tests; Weathering
• Old TRIS Terms: High strength bolts; Question d90
• Subject Areas: Bridges and other structures; Railroads;

Filing Info

• Accession Number: 00052900
• Record Type: Publication
• Source Agency: International Union of Railways
• Report/Paper Numbers: D90/RP 4/E
• Files: TRIS
• Created Date: Nov 23 1976 12:00AM