Optimizing strength properties of M40 grade concrete using response surface methodology: investigating the influence of waste PET-Fs (coated and uncoated) and mineral admixtures

The issue of waste generation and its management is rising nowadays. However, despite controlling waste generation, significant efforts were diverted towards identifying alternative ways of waste management. Research, encouraging the use of waste materials as a construction material, has been going on for several years. The present study will focus on utilizing the waste PET plastic in the form of Fibre with a specified aspect ratio in the matrix. The effect of coated Fibre on the various properties of concrete (Mechanical Properties) will be evaluated. The effect of distinct mineral admixture i.e., Ground Granulated Blast Furnace Slag, Silica Fume, and Sugarcane Bagasse Ash with the plastic on the matrix will be studied. PET-Fs in concrete added in proportion 0.36%, 2%, 6%, 10% and 11.46 in aspect ratios 3.85, 10, 25, 40 and 46.15. Results indicated that the 7-day and 28-day Compressive Strength of the concrete samples with PET-Fs were observed to be lower than the control samples. However, on coating the PET-Fs with SF, GBFS and SBA, a significant increase in the 7-day and 28-day Compressive Strength was observed. Coating of PET-Fs with mineral admixtures further led to an increase in their split tensile strength. Maximum increase in flexural strength of concrete was observed in the order of SF-coated < GBFS-coated < SBA-coated PET-Fs. Overall research concludes that the addition of PW in existing concrete roads can manage approximately 18,847 kg of the city's plastic waste.