By 1990, a group of engineers formulated (and later patented) the first industrially stable version of the polystyrene concrete by mixing in certain additives.
A request from Argentine lead to the final formulation of the product, where they identified a big problem in pine tree leaf waste and they were interested if it could be used as aggregates.
The patent had been filed in 2015[2] and awarded in 2017/2018 that covers any possible additive that enables the replacement (fully or partially) of natural aggregates by mixed shredded solid waste granules.
The special additive is produced in a factory and shipped to the site of application in 5–25 kg bags.
On the working site, only the traditionally used concrete processing tools are needed for mixing, pumping or casting, which means no extra costs and a very high rate of market availability.
[citation needed] Not applicable for: weight bearing structural concrete, high-friction contact surface.
The input plastic types are very limited as they have to melt into the asphalt mix at 165 degree Celsius (thermoplastics), and the technology has a high initial investment and low expandability.
Car tire granulates are used in road base as a stabilizing layer or in small quantities as a binding agent in asphalt.
[8] The replacement of fine aggregates in concrete (e.g. sand) with plastic naturally will decrease the Young’s Modulus and compressive strength of the material, as plastics have lower strength than typical fine aggregates, and their hydrophobic properties decrease their adhesion to the concrete matrix at the interfacial transition zone.
Studies show that treating plastic aggregate with gamma radiation before adding to the concrete improves compressive strength of the material.
[12] Similarly, microwave radiation pre-treatment of PET was shown to improve adhesion with cement paste.