Prediction of strength of foamed concrete containing waste plastic as coarse and fine aggregates using Minitab software

In this research, waste plastic as aggregate was used in production of foamed concrete as partial replacement of sand. The Minitab program was used to determine the number of experimental mixes (mix proportions). After that, these mixes were mixed, poured, cured to investigate their required compressive strength. Finally, the strength values of all the mixes were analyzed and the best mix was predicted with the best improvement in strength. Four mixes were relied on as being the best among the 31 experimental mixes. In these mixes, the cement ratio is fixed, as 400 kg / m
³
and the percentage of fly ash as 60 kg/m3, the proportion of fine plastic is 15%, and the proportion of coarse plastic is 70%, with the constant ratio of water to cement and constant amount of foam. Comparing the reference mix with that containing 70% coarse waste plastic, it was found that the decrease in strength is about 9% and the decrease in density is about 16%. While, compared to the mix containing about 89% fine and coarse waste plastic, it was found that the decrease in strength is about 24% and the decrease in density is 23%. The results showed that the use of plastic as aggregates caused a negative effect on the strength values, however; a good reduction in density was achieved.