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| Thread ID: 124871 | 2012-05-24 14:58:00 | Stiffer Pavement? | SurferJoe46 (51) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1277219 | 2012-05-24 14:58:00 | Many years ago when I was physically fit - about 1960-70 or so, I used to ride a bicycle . I had a road bike, not like those of this era . It was a J . C . Higgins from Sears and it had a two-speed 'kick-back' shift, hub brake and huge tires with a front coil spring shock absorber . Memories . Anyway - I always noticed that pedal pressure went up when I ran on asphalt verses concrete, and of course in colder weather cold asphalt was easier to move on than hot asphalt . I kept this thought for years and although it occasionally flashed in my memory, never thought much more about it until now . It seems that some brightwit nuclear physicist-type has recommended stiffer paving to save fuel . Rolling resistance on soft pavement is drinking fuel it seems --- more so than harder, less rubbery pavement . I knew that . Why didn't I see the possibility! I couldda been rich with this same idea! A recent study conducted by civil engineers at MIT found that using stiffer pavements on U . S . roads could cut vehicle fuel consumption by as much as three percent . That savings could add up to 273 million barrels of crude a year . Stiffer roads also would reduce annual carbon dioxide emissions by 46 . 5 million metric tons, according to the study released in a recent peer-reviewed report . There’s no shortage of road studies . This is the first to use mathematical modeling rather than roadway experiments to evaluate the effect pavement deflection has on fuel consumption across the entire U . S . road network, MIT said in a release . The study’s authors, Professor Franz-Josef Ulm and student Mehdi Akbarian, modeled the physical forces that occur when a rubber tire rolls over pavement . They contend that the energy is dispersed so that the maximum deflection of the load is behind the path of travel . This makes the tires on the vehicle drive continuously up a slight slope — and in turn, increases fuel use . Just like it takes more energy to walk in sand than on a hard surface, cars use more fuel when there’s constant upward slope to deal with . Road roughness and deflection are responsible for an annual average extra fuel consumption of 7,000 to 9,000 gallons per lane-mile on high-volume roads in the 8 . 5 million lane-miles that make up the U . S . network . The authors says up to 80 percent of that extra fuel consumption could be reduced through improvements in the basic properties of asphalt, concrete and other materials used to build roads . LINK::: . smartplanet . com/blog/intelligent-energy/how-stiffer-pavement-could-save-millions-of-barrels-of-oil/16240?tag=nl . e660" target="_blank">www . smartplanet . com I guess I missed another golden goose . |
SurferJoe46 (51) | ||
| 1277220 | 2012-05-24 21:00:00 | We have 2 kinds of seal here smooth seal which is great for cycling on and chipseal which is hard work to pedal on, especially on a cycle with 23mm wide tyres | gary67 (56) | ||
| 1277221 | 2012-05-24 23:31:00 | Using that reasonoing, perhaps we should also move away from rubber tyres ("tires", for SJ)?? Maybe go back to nice sturdy solid wooden wheels - on a concrete surface, of course!! It might cut those damn boy racers back a notch!!! They'd just have competitions to see who could do the best "woody"!! ;) :D |
johcar (6283) | ||
| 1277222 | 2012-05-24 23:33:00 | . | johcar (6283) | ||
| 1277223 | 2012-05-24 23:42:00 | We have 2 kinds of seal here smooth seal which is great for cycling on and chipseal which is hard work to pedal on, especially on a cycle with 23mm wide tyres For SurferJoe that is hotmix seal and chip seal. One possibility they have not considered is that braking and cornering could be affected by the harder seal so cause more accidents and so negating the benefits. |
mikebartnz (21) | ||
| 1277224 | 2012-05-24 23:43:00 | We have 2 kinds of seal here smooth seal which is great for cycling on and chipseal which is hard work to pedal on, especially on a cycle with 23mm wide tyres For SurferJoe that is hotmix seal and chip seal. One possibility they have not considered is that braking and cornering could be affected by the harder seal so cause more accidents and so negating the benefits. |
mikebartnz (21) | ||
| 1277225 | 2012-05-25 03:10:00 | It seems that some brightwit nuclear physicist-type has recommended stiffer paving to save fuel . They're called trains - steel wheels on steel rails . |
decibel (11645) | ||
| 1277226 | 2012-05-25 04:13:00 | I am led to believe that road surfaces in many countries, the US being one of them, are on average much smoother than our roads here in NZ. Our rough road surface is harder on tyres, increases drag, and adds a lot of road noise (you really notice the drop in sound and improvement in ride when you hit one of the rare stretches of smooth seal). I don't know what the reasoning is here but I suspect it's about available materials and cost. I am not sure of the safety implications, in the dry a smooth road has no disadvantage with plenty of grip but in the wet it might be a different story. You could also go back to the old style giant spoked wheels with thinner tyres - less rolling resistance and believe it or not the width of a tyre has virtually no effect on traction on a hard surface. Most young cyclists around here seem to ride mountain bikes - not really making life easy for themselves on a road. They could change to road tyres and increase the tye pressure and have a much easier time of it but I don't see many bothering. |
dugimodo (138) | ||
| 1277227 | 2012-05-25 04:26:00 | I don't know what the reasoning is here but I suspect it's about available materials and cost. It's all to do with cost but I do wonder if the long term cost is greater with chip seal because it needs doing more frequently and in hot weather you can see the tar come to the top making a dead smooth and dangerous surface. Because of the sound factor I reckon all roads within town/city boundaries should be hot mix. |
mikebartnz (21) | ||
| 1277228 | 2012-05-25 04:29:00 | Dunno about cost but we have had large sections around Nelson resurfaced this year and on some roads they have used both types of seal in patches so goodness knows what the thinking is. Chipseal is definitely more wearing on tyres | gary67 (56) | ||
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