Suitability of Plastic Paving Blocks for Construction of Non-Motorised Transport Facilities

Abstract

Walking remains the oldest and most common mode of transport making up a portion if not most or all of our daily commute. However, there is inadequate infrastructure within our urban centres to cater for the pedestrian volumes experienced because most of the transport infrastructure developments in our urban areas have a bias towards motorised transport. This has led to pedestrians and cyclist being the most affected in road accidents; inadvertently leading to them been categorised as vulnerable roads users. The world is currently producing 300 million tonnes of plastic waste with Kenya contributing 407,506 tonnes per year, and with increasing population, urbanisation and development; the annual plastic waste produced shall continue to increase. Due to widespread littering, plastic waste has become a common sight in our urban and rural areas and the non-biodegradability of plastic makes proper disposal of plastic waste a menace. Asphalt and concrete, which are the conventional materials used for the construction of the walkways and cycle lanes, are most ideal for the motorised transport pavements and can prove to be expensive for use in low volume pavements. The influx in plastic waste in our society, could make plastic paving blocks a suitable alternate construction material that can be affordable, readily available and environmentally friendly if adopted. This study assessed the suitability of plastic paving blocks for use in the construction of walkways and cycle lanes; by determining their physical and mechanical properties, and undertaking a purchase cost analysis on samples provided by Corec Kenya. The plastic paving blocks are manufactured by mixing sand with red oxide. This mixture is mixed with shredded plastic at a temperature between 1400 – 1700 c. The physical and mechanical properties tested in this study were total water absorption rate, tensile strength and abrasion rate in accordance with South African National Standards - SANS 1058:2021. All properties investigated were within the recommended specifications in SANS 1058:2021. The purchase cost of one square meter of plastic paving block was compared to that of concrete paving blocks and it was determined plastic paving blocks are 40¢ more costly. However, the impacts the use of plastic waste has on environmental pollution negates this. Based on these findings, this study recommends that plastic paving blocks are suitable for use in construction of Non-Motorised Transport Facilities.