need laminated neoprene bridge bearing info
need laminated neoprene bridge bearing info
(OP)
Hello,
The 15th Ed. of the AASHTO Stnd. Road and Bridge Spec., sect. 14.4.1 had stress / strain curves for elastomeric bridge bearing pads as a function of shape factor. I would like to locate an electronic version of these curves. It could be just about any format, vector (CAD), graphic such as jpg or bmp, pdf, etc. I'd like to include it in my mathcad design file.
In particular I need the ranges similar to the ones in the AASHTO chart, below 1 ksi. I've found one chart on the web at the Nebraska Dept. of Roads site, but the curves do not show the low stress range in enough detail to be useful to me.
Thanks,
Randy Miner
The 15th Ed. of the AASHTO Stnd. Road and Bridge Spec., sect. 14.4.1 had stress / strain curves for elastomeric bridge bearing pads as a function of shape factor. I would like to locate an electronic version of these curves. It could be just about any format, vector (CAD), graphic such as jpg or bmp, pdf, etc. I'd like to include it in my mathcad design file.
In particular I need the ranges similar to the ones in the AASHTO chart, below 1 ksi. I've found one chart on the web at the Nebraska Dept. of Roads site, but the curves do not show the low stress range in enough detail to be useful to me.
Thanks,
Randy Miner






RE: need laminated neoprene bridge bearing info
D.S. Brown
Watson-Bowman
RE: need laminated neoprene bridge bearing info
What I would really like to do is automate this part of the design. Anyone know of equations for the strain as a function of stress and shape factor? Otherwise I think I'd have to curve fit each shape factor curve in the chart, then interpolate between for a given shape factor. I'd rather not do that in mathcad if I can help it...
RE: need laminated neoprene bridge bearing info
Well, there are some equations in the 15th ed. of the AASHTO standard specs that I think*should* result in the same compressive strain as the charts. Looking in the definitions for section 14 there is:
the effective compressive modulus Ec=3*G*(1+2*k*S^2) (psi)
Where k is an adjustment factor that depends on hardness, given in table 14.3.1
and S is the shape factor.
And then strain is P/(A*Ec)
This seems very straightforward, except that it does not give me the same strain as the graphs. So maybe I'm missing something here. I also have to take a look at the LRFD commentary tomorrow, as I think there may be some relevant info there.
Anyone familiar with this issue?
RE: need laminated neoprene bridge bearing info
As far as getting an electronic picture of the graphs, you might try a company called:
Amscot Structural Products Corp.
www.amscotnj.com
RE: need laminated neoprene bridge bearing info
RE: need laminated neoprene bridge bearing info
RE: need laminated neoprene bridge bearing info
http://www.steelbridge.org/scef/SCEF%20Manual%2005.pdf
RE: need laminated neoprene bridge bearing info