New to the forum with a specific question - I am working on a project for NASA at KSC in which we are tasked to find sources of gravel that can be used on their Crawlerway. Does anyone have a suggestion for sources (either general locales or specific companies) that produce hard, rounded, abrasion or fracture resistant gravel? They use it as a loose layer (1 ft thick I believe), not for concrete aggregate.
The Crawlerway is the road used to transport the launch vehicle and shuttle from the VAB to the launch pads (4-5 miles I believe). The load projected for the next generation Ares rocket is 25 million pounds. Their tests indicate that well-rounded coarse gravel produces the least amount of friction both internally and between the road and crawler tracks, hence the reason the use it loose. They currently use an Alabama river rock (river run quartzite gravel). A report from the 60s said Wisconsin glacial gravel (containing mostly igneous rock) was the best of the materials tested. I would like to track down that source but have no other info, and it’s likely that the source from the 60s is no longer in operation or the rail lines from northern Wisc have been converted to bike trails.
I appreciate the help,
Allan (a geologist in Florida, no soft-rock jokes please)