Self-cleaning surfaces as an innovative potential for sustainable concrete

Concrete technology is subject of continuous development and improvement. One of the very recent contributions to durability and sustainability of concrete is the self-cleaning ability. This effect is achieved by applying photocatalytic materials to the concrete mix. This paper describes the effect of self-cleaning and air purification. Since about 10 years concrete paving stones, provided with this function, are available. With the development of a test setup and using nitric oxide (NO) as model pollutant an approach was found to quantitatively assess the air-purifying ability of those paving stones. This seems to be of interest since a real comparative analysis of air purifying concrete products is not available and the establishment of a measurement standard for concrete products is still in a draft-state. A brief technical description of this test setup will be presented to the reader. Using this innovative setup, the influences on the degradation efficiency are studied and a basic reaction model is derived.