Quartz as Aggregate in HMA

I see no compatibility issues with quartz and asphalt, if quartz is readily available.

Thanks lyn... do you or anybody know some company/person who had experience using quartz as aggregate in Hot Mix Asphalt ??

Only problem I see is like most silica based product and liquid asphalt is that they don't adhere to each other very well causing a high use of liquid asphalt and premature failure of the HMA. With the smooth surfaces of the quartz aggregate there maybe issues of stripping. Couple years ago the thought was to use crushed glass in mixes. Only problem is the glass never adhered to the asphalt causing a premature failure of the HMA.

I do understand there is technology modifying asphalt, meaning that chemically add something to improve the adherency, compatibility, etc. I am not sure, but in Texas USA they found the way to get it done.... but no idea how ???!!!???

I found one source in Utah that uses 100% quartz in their asphalt. The asphalt mix is used strictly in desert climates. There is a additive that's added making up to 2% of the total mix design, and on average 6% asphalt. That's 8% liquid added to your mix. That a lot of money in liquid asphalt.

The problem with quartz and other silica based aggregates is that the are hydrophilic (water loving). So if you are in an area that has a lot of water it will strip the asphalt away.

I did find a study from Texas AM they suggest not use 100% quartz unless you are in a desert climate with less then 10-20 inches of rain annual. They suggest a 90% limestone 5% quartz (silica) mix as the best.

I have to agree with bakerjohn on this one. There is bound to be a problem of HMA adhesion to the quartz.

Also, I would be hesitant to use quartz as it's likely to fracture along any number of planes when under applied load.

I do not see any problems with hardness of quartz though.....

2 out of 3 = not a good choice IMO...unless you do extensive laboratory testing of the asphalt pavement prior to placing it.

Ohhh mannnnnn, Mexico....I'd rather forget my last bout with "Montezuma's Revenge" during my trip to Cancun 13 years ago...ACKKKKK!!!!!!!!

Sand = quartz, mostly. So why not do concrete rather than asphalt?