RESUMO
The hazards of polymer waste and emitted gas on the environment pose a global challenge. As a trial to control this, the current work aims to reuse the polymer waste mix (PM) as fillers in calcium silicate to prepare new composites of environmentally friendly polymer concrete. PM was first subjected to treatment to obtain treated PM (TPM) and then was filled in new dicalcium silicate cement with different concentrations. The microstructural characterizations declare the successful preparation of the dicalcium silicate base material. After the curing reaction, the precipitated carbonate main product is responsible for the gained properties. The CO2 uptake% in the proposed composites reached 16.6%, referring to the successful storage of CO2 gas during curing. The treatment reaction led to an increase in the flexural and compression strengths due to the strengthening of the polymer waste mix-cement interface; the strengths were increased gradually with more contents of TPM fillers. 7% TPM-cement concentration achieved the highest flexural strength and compression strength of10.2 and 12.7%, respectively, compared with blank cement. The used polymer improved slightly the pull-off force of the prepared cement, and 7 and 5% TPM-cement composites have the maximum values. All the proposed composites passed the impact testing without failure, where the combination between the polymer waste and silicate cement resulted in a stable composite surface. Compared with the blank, the different concentrations of TPM-cement composites show more stability against water absorption. In addition, the proposed composites and blank cement have a very low carbon dioxide emission. The ability to recycle the polymer waste, form new type of low-energy silicate, improve the mechanical and surface properties, uptake CO2 gas, and reduce gas emission makes the proposed polymer waste mix-cement composites as environmentally friendly construction products.
RESUMO
Climate change is being currently faced globally; controlling the plastic waste and gas emission is aimed to reduce their hazardous effects. In this work, polyethylene terephthalate (PET) and polyvinyl chloride (PVC) polymer wastes are used as fillers to calcium silicate. Chemical treatment was performed to get the best efficiency of the binder material with the treated PET (TPET) and treated PVC (TPVC). The used silicate, new nonhydraulic dicalcium silicate, was synthesized by sintering. A new environmentally friendly polymer concrete, based on different concentrations of PET-/TPET-/PVC-/TPVC-dicalcium silicate composites, was prepared and cured by carbonation. FTIR analysis confirms that the treatment gave functional groups on the polymer surface; also, the hydrophilicity was increased after treatment. SEM photos show that the treated polymers have a rougher surface, which led to improved attachment with cement. The structures of the prepared and cured cement materials are proved by XRD, FTIR analysis, and SEM, through the change of calcium silicate to carbonate. Carbon footprint is used to analyze the environmental implications of the prepared composites. After the treatment reaction, the TPET-cement and TPVC-cement composites showed improved compression and flexural properties and more stability against water absorption. The novelty arises from recycling this plastic waste in the proposed low-energy dicalcium silicate cement, for the first time, to give improved environmentally friendly composites after converting CO2 gas to carbonates, with the reduced carbon footprint.
