Static load testing of glass block window panels
Client: The Home Office
Objectives:
- to record the measured deflections of the panel under a uniformly distributed static loading condition,
- to determine the failure mechanisms.
Test series:
Two tests were carried out on window panels of length 1790mm and width 1040mm.
Methodology:
The glass block panels were tested horizontally, placed upon a R.S.J. ring frame and supported along each edge by means of a continuous flat bearing strip, whose inside edges were in line with the internal opening of the window.
The load was applied using 8No. equal area hydraulic cylinders, via 8 R.S.J. load spreading beams to 16 node points at the intersections of the panel concrete ribs. Pivot joints were used between the load spreading beams and the 40mm x 40mm steel loading pads placed on the concrete surface. The hydraulic cylinders were connected to an electric pump unit, which was used to apply the test loads.
Instrumentation:
A pressure transducer fitted to the hydraulic circuit of the electric pump was used to determine the total applied load.
Displacement transducers were used to measure:
- The deflection at 4 loading nodes displaced around the central glass block,
- The deflection of the central glass lens unit.
The pressure and displacement transducers were monitored continuously throughout the test, scans of data being recorded every 2 seconds.
Test procedure:
After an initial scan of the deflections at zero load was made, the load was increased at a constant rate of 5kN/minute until there was either a loss of specimen stiffness or an unacceptable deformation of the window panel.