Researchers at Louisiana State University (LSU) are close to bringing bendable concrete to mass adoption, producing cost-effective engineered cementitious composites (ECC) that uses readily available ingredients. To date, testing has suggested that the bendable concrete could greatly improve the transportation infrastructure in the region.
The project has been funded by the Transportation Consortium of South Central States and testing began on four different types of sand, two types of recycled crumb rubber materials, fiver different types of fibre, and three different types of flyash. Several ECC mixes were evaluated for compressive strength, tensile strength, deformation capacity, flexural performance, workability, and cracking performance.
Following testing, ingredients that were settled on included a type of PVA fibre that is readily available in the US market, locally available fine river sand, and locally available flyash.
“Compared to typical concrete, our cost effective ECC material has about 300 times more deformation capacity, more than two times the flexural strength, and a higher compressive strength,” said Gabriel Arce, Senior Research Associate at LSU’s Bert S. Turner Department of Construction Management and Principal Investigator on the LSU ECC project. “The cost of our material is approximately 2.5 times that of regular concrete – typical ECC cost can be more than four times that of regular concrete.
“However, when you factor in the possibility of building pavements at half the thickness and enhanced construction productivity due to the ability to construct pavements without joints, the cost of pavements with our ECC material should be comparable to that of traditional concrete. ECC has the potential to provide more durable and reliable concrete pavements that can mitigate the necessity of recurring repair, saving time and money.
“We were able to tailor the cementitious mix and the interface between the fibres and the cementitious matrix in such a way that allowed for the ductile behaviour of the concrete. In more simple terms, the formula utilises the right materials in the right proportions.”