Evaluation of action mechanism, mix design and some properties of photocatalytic concrete

With the use of photocatalytic materials, it was understood that self-cleaning and anti-bacterial properties are gained in cementitious systems and indoor air quality is improved. It was determined that Nano-TiO2 (nT) is used as the most common photocatalyst due to its advantages. Anatase phase, which is one of the phases of nT, was found to be the most preferred photocatalyst because it has a faster photocatalytic effect. In this study, a detailed literature search was conducted on the photocatalysis process, the photocatalyst selection criteria, the materials used in the production of photocatalytic concrete and their mix design. In addition, the effects of the use of nT on the setting time, flow performance, rheological behavior, degree of hydration, pore structure and strength performance of cementitious systems were investigated. It was determined that nT is used at rates ranging from 1-10% for the production of photocatalytic concrete. It was observed that the hydration rate of cementitious systems increases with the increase in the use of nT, and the flow performance and rheological behavior are adversely affected. Also, it was emphasized that the use of nT improves the mechanical properties by reducing the void volume of the system. However, it was reported that the use of nT above a certain rate causes the strength performance of cementitious systems to be adversely affected.