Enhancing the hydrophobicity of concrete in harsh conditions

Researchers from Brunel University London discovered that concrete facing a harsh environment – for example heavy rainfall or high winds – deteriorates slower when a crystallising material is added to the fresh mixture, followed by a wax-based curing agent.

Silane based materials are toxic

The findings could help increase the lifespan and reduce the long-term cost of concrete structures in severe conditions. “Concrete under harsh environmental conditions suffers from accelerated deterioration,” said research leader Mazen Al-Kheetan. “Industry has been trying to overcome this problem by applying protective materials, which are mainly silane or siloxane based, but the problem with them is high toxicity and a dangerous impact on the environment.”

Blend reduces penetration of water

Working alongside Texan company Chem-Crete, the researchers created a new protection-curing blend that reduces the penetration of water and harmful chemicals, whilst increasing the compressive strength compared to untreated concrete. It is environmentally friendly and can be applied on dry and wet surfaces of concrete without affecting its performance.

Protecting any concrete structure

The material works by absorbing water that exists within the concrete to form crystals. Whenever the crystals are formed they line the pores of the concrete, allowing it to breath. It also works on repelling water that tries to penetrate through. This novel approach will help protect any concrete structure from the penetration of water and harmful chemicals like chlorides and sulphates.

Investigation of other hydrophobic materials

Research is now underway to investigate the performance of other hydrophobic protective materials that are environmentally friendly, can reduce water absorption level, and be applied to fresh concrete.

The study is published in: Construction and Building Materials, Vol. 160, 30 January 2018.