Compressive Strength and Treatment Efficiency of Nitrogen-Dioxide of Paving Block Made of Concrete Mixing with Titanium-Dioxide

Abstract

Abstract

This research studied the treatment efficiency of Nitrogen-dioxide (NO2) in air using concrete paving block
containing Titanium-dioxide (TiO2) which were 5x5x5 cm3 cubic specimens. They were plastered with concrete mixed
with TiO2 in the percentage of 0, 5, 10, and 15 by weight for the top layer of the specimens at 1 cm. This research studied the effect of doges of TiO2 on compressive strength at the age of 3, 7, 14, and 28 days and the NO2 treatment in air. The 28-cured days of specimens treated NO2 for several cycles (48 hours / cycle). The results showed that the doges of TiO2 did not effect on the compressive strengths of concrete paving block which was higher than designed mixes. For NO2 treatment, the treatment efficiency of concrete paving block containing 15 wt.% of Titanium-dioxide had higher than the
specimens. The 1st cycle for treatment had the efficiency of 48% and decreased when retreated in next cycles. At the 7 th cycles, the efficiency of concrete paving block decreased to lower than 10%. After that the tested specimens were
polished in order to remove the surface of concrete paving block for 0.1 cm. and retested. The efficiency of retested
specimens was similar to new specimens. The polished surface of concrete paving block was stimulated corrosion on pathway and road. In addition, concrete paving block containing Titanium-dioxide were soaked in diluted Sulfuric acid in order to stimulated contact with acid rain. The results showed that concrete paving block containing Titanium-dioxide soaked in diluted Sulfuric acid (pH = 5) had the strength development and NO2 treatment efficiency were lower than when compared with specimens which soaked in water about 10 to 20 percent