Partially replacing sand with waste plastic in concrete mix.

I am a student currently preparing a dissertation on the above topic. I was hoping to have some opinions from profesionals, or anyone who would like to make a comment. 

Sand when partially replaced with granulated waste plastic (around 10% of its weight) is almost as strong as normal, although its only slightly as strong, it could potentially save 820M.t of sand a year, and obviosuly remove that amount of waste plastic from the environment. 

Would people in industry and companies be willing to make the effort to make this small change?

Soil Mechanics / Geotechnical Design Construction Research Environmental Geotechnics Engineering Geology Structural Geology / Geomorphology