Conceptualization and Design of a Small Pyrolysis Plant for the Sustainable Production of Flexible Bricks and Bituminous Concrete from Polyethylene Terephthalate Waste

Polyethylene terephthalate is majorly used for packaging of various products because of its resistance to chemical attack and environmental degradation, but the proper disposal of this non-biodegradable material has been a major challenge. Pyrolysis is the melting of plastic in the absence of oxygen. Currently pyrolysis of polyethylene terephthalate is considered as a viable recycling method since it only requires 5% of the calorific value of polyethylene terephthalate. This research was aimed at designing a pyrolysis plant for the production of construction materials with acceptable mechanical properties such as compressive strength and water absorption. Sustainable, eco-friendly road construction from bituminous concrete with waste polyethylene terephthalate has the capability of reducing carbon emissions. The polyethylene terephthalate bituminous composite has the flexibility of plastic but strength of concrete. The bricks have a maximum compressive strength of 10 N/mm2 which is within the standard range and have less water absorbing tendencies hence have a longer lifespan. Value addition is equally important in the pyrolysis plant so as to contribute to sustainable development. This book chapter reviews the different products such as polyethylene terephthalate composite bricks and flexible pavements which can effectively use polyethylene terephthalate waste as a raw material.

Characteristics of Bituminous Concrete Mixtures Utilizing Copper Slag

Study work on the effectiveness and use of Industrial by-products (IBP) in flexible pavements is restricted. Several factors however need to be analyzed specifically before a greater proportion of industrial by-products can be used in bituminous concrete mixtures with a high level of confidence. Effects of copper slag on volumetric and strength parameters such as Marshall Parameters, static tensile properties, and moisture resistivity of bituminous concrete mixtures using copper slag as mineral fillers need to be examined and thoroughly analyzed. Quantitative analyses of the elements and the morphology of the copper slag have been studied by Energy Dispersive X-ray Analyzer (EDX) and Scanning Electron Microscope (SEM). The use of copper slag as a mineral filler in bituminous concrete grade-2 mixtures showed an increase in stability, indirect tensile strength, and moisture resistance compared to traditional mixtures. Keywords— Industrial by-products (IBP), Indirect Tensile Strength, Moisture resistivity, SEM, EDX