Researchers on the path toward developing salt-resistant pavementMarie Donlon | July 29, 2019
Researchers from Brunel University London have developed a new concrete formula that will absorb considerably less salt than traditional concrete, thereby reducing corrosion and deterioration of roadways.
According to researchers, the new mixture absorbs almost 65% less water and 90% less salt — both of which contribute to corrosion and deterioration of roadways — than standard concrete mixtures. Generally, salt, otherwise known as sodium chloride, is spread on winter roadways to prevent them from freezing over and causing slick driving conditions. While most of the salt washes away, a substantial amount is absorbed as salty water, causing the concrete to deteriorate and for the steel within to corrode and rust. As such, the Brunel University researchers added sodium acetate compound into a standard concrete mixture.
"Incorporation of a sodium acetate compound into concrete, at the mixing stage, works on absorbing some of the water to form crystals that line the walls of the pores in the concrete," explained Mazen Al-Kheetan, a Ph.D. student at Brunel University's Department of Civil and Environmental Engineering, who is leading the project.
"These crystals increase the hydrophobicity of the concrete — the amount concrete repels the water — which ensures the reduction of water uptake through the pores," added Al-Kheetan.
Additionally, by applying the de-icing salt to pavement composed of the new mixture, researchers determined that the protective compound within the pores of the concrete also warded off both water and waterborne chlorides. Likewise, the team determined that the new mixture had improved the concrete mixture’s compressive strength by 42%, according to the research.
Although the concrete mixture is still undergoing evaluation, its developers believe the new formulation may offer significant cost savings as it is less expensive to produce and easier to prepare than current concrete mixtures.
The research — Integration of Anhydrous Sodium Acetate (ASAc) into Concrete Pavement for Protection against Harmful Impact of Deicing Salt — is published in The Journal of The Minerals, Metals & Materials Society.