Plastic road offers a greener way to travel in Bangladesh

Infographic: TBS

After constructing the maiden road by plastic waste mixed bitumen in Gazipur, the Local Government Engineering Department (LGED) now looks to widen the piloting – which aims at stronger and longer-lasting roads at cheaper costs and better management of the non-biodegradable plastic waste.          

LGED officials said they will begin road construction in Cumilla's Monohorpur and Laksam upazila within the next two-three months by plastic-mixed bitumen.  

Besides, the LGED aims at constructing a 1km road using plastic waste in each of the 64 districts in Bangladesh in 2023, according to the department's Superintending Engineer Abu Mohammad Shahriar. 

In a separate development, the Roads and Highways Department – which is now conducting joint research with a US university – says it will start the piloting of the greener construction next year on a national highway.   

Engineers and public officials said plastic waste in road construction reduces the costs and makes roads stronger to withstand adverse weather impacts such as a heavy rainfall and flooding. Such construction also helps protect the environment by taking away the discarded plastic items from landfills and dumping zones.  

Referring to the 100-metre maiden plastic road in Gazipur, LGED Superintending Engineer Abu Mohammad Shahriar said they used a mixture of 9% plastic waste and 91% bitumen. The mixture was heated at 160 degrees Celsius before the carpeting. 

In other words, bitumen use on the road was slashed to 91kg from the previous 100kg.

"Bitumen is now at around Tk80 per kg, while polythene is almost free. We just sourced it from the landfill," said Shahriar. He estimated that plastic waste use will save up to Tk20 lakh per 5 km road.  

 He claimed the Gazipur road will last for at least 5 years thanks to the use of plastic, whereas any normal road in the country lasts for an average of 2-3 years.

"Regular bitumen tends to melt out at around 40-degree Celcius. But if it is mixed with plastic waste, the softening point surprisingly jumps to 60-degree Celsius," the LGED engineer noted.

He said the mercury in Bangladesh usually hovers around 35-degree Celsius, while roads heat up to 40-45 degree Celsius due to traffic movement. "The plastic will prevent rutting of asphalt. Besides, it will prevent road damage from the monsoon."      

Bangladesh annually generates more than 8.21 lakh tonnes of plastic waste, according to non-government organisation Waste Concern. Of it, only 5.27 lakh tonnes of discarded plastics are recycled as the remaining items are left untreated. 

A report by the World Bank last year showed Bangladesh's annual per capita plastic consumption in urban areas tripled to nine kg in 2020 from three kg in 2005.       

Citing the LGED initiative to build 1km plastic road in each district, engineer Shahriar said that 50-60 kg of plastic will be required to construct 25 km of road, which will eventually reduce plastic waste in the country to zero.    

India's chemistry professor Rajagopalan Vasudevan first introduced the idea of plastic road. The idea emerged from his workshop at the Thiagarajar College of Engineering in Madurai as far back as 2001. India so far has built 2.5 lakh kilometres of road by plastic mixed bitumen.   

The alternative plastic management is road construction is also gaining popularity in other countries including Vietnam, Pakistan, the Philippines, South Africa and the US. 

The LGED said it is going to introduce another piloting where there will be a plastic waste layer with asphalt carpeting above and underneath.   

In a similar move, the Roads and Highways Department said it will begin plastic road piloting next year. Currently, the department is carrying out repairs of the Dhaka-Chattogram highway with imported polymer bitumen.    

Md Waliur Rahman, additional chief engineer of the Roads and Highways Department, said the use of polymer bitumen is an established method worldwide to make roads stronger and last long. Though it is being imported, the material can be produced locally.   

Waliur said the Roads and Highways lab is now conducting tests to see whether the plastic bitumen could widely be used on highways too.    

"We are now conducting a joint study with Texas State University. Once the research is done, we will pick a national highway for plastic-bitumen carpeting," Ahsanullah Habib, director of the Bangladesh Road Research Laboratory, told The Business Standard. 

Shamsul Hoque, a public transport expert and also a civil engineering professor of the Bangladesh University of Engineering and Technology (BUET), appreciated plastic use in road construction as he noted the mix will help make roads long lasting and provide a better solution to plastic waste management.     

"We have to start looking at plastic as raw material rather than waste," he said.