India has been experimenting with plastic for the past 15 years and found that it results in less maintenance costs as the roads are less prone to potholes.

Bernama reported that the conventional asphalt for road paving is losing its lustre due to its short lifespan, which has led to higher road maintenance costs.

Asphalt, a mixture of bitumen (a sticky black and highly viscous liquid) and aggregate (sand, gravel and crushed stone), is used for surfacing roads.

The Public Works Department’s Centre of Excellence for Engineering and Technology (CREATE) is currently testing road pavement technology utilising not only waste plastic asphalt but also latex asphalt.

These experiments are being conducted at two sites — the FT98 federal road in Kerdau, Temerloh, Pahang; and FT3 federal road in Chukai, Kemaman, Terengganu.

CREATE Road Research Laboratory head Mohd Hizam Harun said the Temerloh site study involved paving a mixture of plastic waste and asphalt on one lane stretching 175m.

Another 645m stretch of road there has been paved with latex asphalt (a mixture of natural rubber latex and asphalt).

At the Kemaman site, CREATE is testing three types of paving materials — waste plastic asphalt over a 615m stretch of road; latex asphalt over a 990m stretch; and latex mastic asphalt over a 1,330m stretch.

Hizam said the findings of the study were expected to be concluded after two years of monitoring the sites but initial observations are positive.

He said India had used plastic waste as a component to pave 25,000km and these roads had proven to be more resilient than those paved with conventional asphalt.

Indonesia had also carried out a similar study in Bali in 2017.

Hizam said 4,000kg of plastic waste had to be mixed with asphalt to resurface 1km of a two-lane road.

The plastic waste is priced at only RM3.50 a kg but only 2% of plastic waste generated in Malaysia can be used for the road paving industry as plastic waste tainted with food cannot be used.

CREATE uses plastic waste purchased from a factory in Kuantan that processes plastic waste disposed of by factories and shopping malls, and not plastic waste found at garbage disposal sites, Hizam said.

He said Malaysia would have to import the plastic pellets from countries like the United Kingdom and Australia to meet its needs if it decides to use waste plastic asphalt as a resurfacing material.

CREATE’s site studies have also shown that the addition of natural rubber latex to asphalt has the ability to improve the bitumen’s characteristics.

Hizam said the latex used for the site studies was purchased from a factory in Johor Bahru at RM6.50 a litre.

The latex asphalt mixture to resurface 1km of a two-lane road will require between 1,000 and 2,000 litres of natural rubber latex.

Hizam said using latex will boost the local rubber industry.