Millions of printed circuit boards from discarded electronics are tossed into landfills every year. In addition to the volume of waste, the material can leach chemicals into the soil. As an alternative, researchers at Shanghai Jiao Tong University in China are finding various ways to reuse the panels, including as an additive in asphalt.

Xu Zhenming and his colleagues stripped the boards of all components, pulverized the remains into a powder and used an electrostatic separator to remove fine bits of any remaining metals, leaving a pulp of glass fibers and resin. They then added those remnants to warmed asphalt, to see if the pulp would act as a binder. Binders such as ground tire rubber and charcoal are typically added to improve asphalt’s stiffness at high temperatures (to reduce rutting) and its pliability at low temperatures (to prevent cracking). The pulp improved both properties, especially when the powder grains were made as small as possible. Zhenming’s team is testing the modified asphalt to check how it holds up to outdoor conditions over time. It is also experimenting with forming the pulp into sheets that could be made into structures such as park benches and fences.

Note: This article was originally printed with the title, "Old Circuit Boards Hit the Road."

11 Comments

1. 1. jamerz3294 10:47 AM 7/7/09

   Nice to see that we really can do something useful with all those discarded parts!

   Reply | Report Abuse | Link to this

2. 2. candide 11:11 AM 7/7/09

   What happens to the removed components and separated metals ?

   Reply | Report Abuse | Link to this

3. 3. Paulo Sargaço 11:16 AM 7/7/09

   And what about those chemicals that leech into the soil?

   Reply | Report Abuse | Link to this

4. 4. jon winchester 01:03 PM 7/7/09

   "leech," scientific american? really? leech? do you even try to proofread anymore?

   Reply | Report Abuse | Link to this

5. 5. jaqcp in reply to jon winchester 03:16 PM 7/7/09

   Computers half spell Czech. Wye waist money awn education ore educated righters?
   
   (Their ar know words misspelled according Tu dictionary.com)

   Reply | Report Abuse | Link to this

6. 6. scientific earthling in reply to jaqcp 07:59 PM 7/7/09

   fi yuo cna raed tihs, yuo hvae a sgtrane mnid too. Cna yuo raed tihs? Olny 55 plepoe out of 100 can.
   
   i cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. The phaonmneal pweor of the hmuan mnid, aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it dseno't mtaetr in waht oerdr the ltteres in a wrod are, the olny iproamtnt tihng is taht the frsit and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it whotuit a pboerlm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Azanmig huh? yaeh and I awlyas tghuhot slpeling was ipmorantt! if you can raed tihs forwrad it.
   

   Reply | Report Abuse | Link to this

7. 7. pgtruspace 11:54 PM 7/7/09

   Hey ehtnraig, no pmerbom.

   Reply | Report Abuse | Link to this

8. 8. frank25 03:49 AM 2/15/11

   Two thumbs up for this kind of idea. [url=http://http://www.act-cw.com]PCB[/url],

   Reply | Report Abuse | Link to this

9. 9. frank25 03:50 AM 2/15/11

   Reply | Report Abuse | Link to this

10. 10. ginnycrandall 11:51 AM 5/13/11

    I definitely approve of this idea. Not only would it create more jobs, but it would reduce the amount of waste in our landfills and help improve the <a href="http://duriepaving.com">paving</a> on our streets. Is there any chance that it will be implemented in the near future?

    Reply | Report Abuse | Link to this

11. 11. ginnycrandall 11:53 AM 5/13/11

    Also, would paving companies like this one: http://duriepaving.com be able to profit from this new method?

    Reply | Report Abuse | Link to this