Bagasse can gain value by replacing sand in construction

Bagasse can gain value by replacing sand in construction

The assessment was made by the technical director of Union of Sugar Cane Industry (UNICA), Antonio de Padua Rodrigues, in the face of recent scientific research focused on diversifying the use of bagasse.

The technique for using the sugar cane ashes in concrete production, developed by researcher and professor at Federal University of São Carlos (UFSCAR), Almir Sales, has been studied for four years. “Currently the ashes are used as fertilizer on crops, but there’s no proof of it is efficiency, it’s only a way to dispose waste. Therefore, if commercial viability is established, it will be a practical solution with many benefits for the environment besides the economic factor, ” says Rodrigues.

For Sales, the new technique is an alternative for waste disposal of the chain. “The ashes will not be deposited in the fields. Also, there’s plenty of raw material for another industry, which is important from an economic standpoint, ” he explains.

The study group coordinated by Sales arose from the need to seek new materials to replace the so-called “natural clusters” of concrete, usually sand – removed from the rivers – and crushed stone, or small pieces of stone from the action of a jackhammer. The ashes generated by burning sugarcane bagasse as a viable alternative was chosen mainly by the large quantity produced. The high volume is a basic requirement for a residue to be considered as an alternative to the sand, since it is widely used in day-to-day.

Strength and durability

According to the UFSCAR researcher, studies with the ashes of bagasse are still in their infancy. The group is evaluating the parameters of durability, which should still take some time. However, research has revealed that the concrete made with sugar cane ashes increases from 15% to 17% the strength of the material.

Currently, 100 million to 120 million tons of river sand are consumed annually in Brazil. On the other hand, around four million tonnes of ashes from bagasse are produced. Therefore, the ashes would represent 4% of the sand.