Heat resistance of lightweight concrete with plastic aggregate from PET (polyethylene terephthalate)-mineral filler

Abstract

The addition of filler to plastic aggregate results in better mechanical characteristics of concrete than concrete with plastic aggregate without filler; this has been proven in various studies that have been conducted. Different types of minerals have been used as fillers; namely, red sand, fly ash, rice husk ash, and cement. The use of plastic aggregate in concrete as a substitute for natural aggregate indicates that the concrete produced is included in the lightweight concrete category. It is interesting to examine the effect of heat on the mechanical characteristics of this concrete. This study will use two types of plastic aggregate which are differentiated based on the filler used. The first aggregate is an artificial aggregate made from PET plastic with rice husk ash filler; the second aggregate uses Portland pozzolana cement. Four proportions of the concrete mixture were made using these two types of plastic aggregate. As a reference, a fifth concrete type Ⅰs created, namely concrete with all-natural aggregate fractions. The test results show that starting at 100 ℃ the concrete with plastic aggregate begins to fine cracks which can only be seen using a digital microscope. While in reference, concrete cracks began to appear at 200 ℃. The presence of cracks causes the mechanical characteristics of the concrete to decrease significantly. On heating of 300 ℃ and 400 ℃, the specimens with plastic aggregate appear charred, and there are holes due to the PET decomposition process, and more cracks with large gaps.

Keywords

• lightweight concrete
• plastic aggregate
• synthetic aggregates
• mineral filler
• pet plastic waste
• heat resistance