PROBLEMS OF HIGH STRENGTH BOLTED CONNECTIONS IN STEEL CONSTRUCTION. COEFFICIENTS OF FRICTION OF FAYING SURFACES SUBJECTED TO VARIOUS PRE-TREATMENTS
The object of the present Interim Report No. 1 consists of: 1. Establishing uniform conditions for the testing proce- dures for the purpose of: 2. Reducing as far as possible the scatter of the values of the coefficient of friction and the pretension; 3. In particular, establishing the effects of different methods used for the preparation of faying surfaces; and 4. Making use, for the work of the Specialist Committee D 90, of the investigations of other bodies in related fields of research. For this purpose, the faying surfaces of five specimens each in steel St 37 and steel St 52, each yielding 10 measured values, were tested with various blasting media (wire shot, corundum, quartz sand, chilled iron grit, and flame-cleaning). Specimens whose faying surfaces were treated with chilled iron grit or quartz sand yielded the highest mean values of the coefficient of friction, the lower limit of confidence of which was above 0.60 for both grades of steel. There are not sufficient grounds to justify the difference in the values of the coefficient of friction of steel St 37 and steel St 52 stipulated in Section 2.2 of the UIC Memorandum 770 R. For faying surfaces prepared immediately prior to assembly and not protected against corrosion, it is recommended that the use of chilled iron grit or of quartz sand be specified for the removal of rust and of mill scale in order to achieve the highest possible values of the coefficient of friction.
- Restrictions on the use of this document are contained in the explanatory material.
International Union of RailwaysOffice of Research and Experiments
- Publication Date: 1966-10
- Features: Appendices; References;
- Pagination: 27 p.
- 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;
- Accession Number: 00052897
- Record Type: Publication
- Source Agency: International Union of Railways
- Report/Paper Numbers: D90/RP 1/E Intrm Rpt.
- Files: TRIS
- Created Date: Nov 23 1976 12:00AM