ASTM C1492 Concrete Roof Tiles

[Paul1961]

I need to perform some flexural testing that is in conformance with the standard. I looked at buying a machine, but it is out of my budget so I plan to build. It does not appear to be that complex. However, looking at some of the machines made for this purpose - they do not seem to conform to the standard. Maybe they conform to a variation for a different country. The main issue is allowing all 3 supports to rotate in the transverse and longitudinal direction. I understand the reason for it. Does anyone have any experience with these test machines and how they are designed to accomplish this? Maybe you can describe how this is done or attach a picture?

 

[Ron]

Such machines are designed using a ball-bearing or hardened steel ball to accomplish the rotation. Keep in mind that the longitudinal and transverse rotation are only necessary for profiled roof tiles such as the Spanish S or barrel tile. Flat concrete tile can be tested on a machine that only has rotation on the supports perpendicular to the long axis of the tile.

The bearing plate has a hemispherical hole machined into it to accept the ball. The profile blocks sit direction on the bearing plate (on top of the lower plates, below the upper plate).

Pay attention to the loading rate of the machine. This makes a difference in the test. Check out each of the standards referenced in C1492 as they give specific requirements for the loading apparatus, separate from the flexural loading jig.