On a Lane Cove day that reached 39 degrees Celsius buckling of paving and drainage grate materials was noticed. The day was the second of similar temperature. The buckling occurred on the Epping Road bridge crossing Stringybark Creek. In particular the observation was on the western side of the road (or the Epping bound side of the road). For an image of the location observe this Google Map image of expansion joint.
Here is a photograph of the expansion joint.
The expansion joint was effectively closed. The expansion joint at the other side of the bridge - the city bound side - was also effectively closed. The difference between the gap in this photograph and the one in the Google Map is probably about 50 millimetres. Therefore, the bridge has probably expanded by 100 millimetres. One presumes that the Google Map image was taken on a cooler day. The Google Map image is dated to November 2016. November 2016 average temperature for Lane Cove was 24 degree Celsius.
A drainage grate that was set within the pavement adjoining the road:
A bicycle path runs through the area of the lifted drainage grate. Indeed, the grate marks the distinction between the Epping bound cycle lane and the City bound cycle lane. Take care if cycling by!
Shalom,
Ozhamada
Note: Links good as at 11 November 2017. I took these photographs on route to a bush food foraging experience. See this linked post.
The magic number for expansion is 12E-6, per degree, per unit length
ReplyDeleteIf the distance between joints = 100m.
If the change in temperature = 25c (say 20 overnight to 45 during the day), the change in length in millimetres is:
100,000 x 12E-6 x 25 = 30mm
ie 15mm each end, if neither end is restrained
Learnt that at university, but here it is on Wicked Pedia
https://en.wikipedia.org/wiki/Thermal_expansion