Fabrication of green anti-microbial and anti-static cement building bricks

Abstract

The design cement mix of grade 350 was created in accordance with Egyptian Standards by partially substituting the fine aggregate with WPVC waste in various weight percentages (10, 20, 30, 40, 50, 75, and 100%). A control mix with 0% replacement was also prepared. The W/C ratio was about 0.5 for all mixes. Compressive, flexure strength, bulk density, and absorption tests were studied. For WPVC replacement, until 30%, compressive strength and flexure strength are acceptable with respect to standerds. Thermal treatment at 200 °C improves the compressive strength, flexure strength and water absorption for 20% WPVC only. The dielectric properties of all cement paste mixes before and after heat treatment, over a frequency range (0.1–10⁶ Hz), were measured as a function of frequency. For dielectric properties and conductivity, an improvement was obtained until 30% WPVC. After this percentage, the dielectric properties and the conductivity got worse. So, cement paste with 30% WPVC as replacement of sand is the optimum ratio with conductivity in range of 10⁻¹² S/cm, which is a good choice for antistatic cement paste applications (10⁻¹⁰–10⁻¹² S/cm). The antimicrobial efficacy of the prepared cement samples of WPVC concentrations (0, 20 and 30) % were studied, the number of grown microbial colonies decreased for all the samples compared to control tap water and decreased by introducing WPVC into the cement paste sample. So, it is recommended to use these samples in places that should be carefully shielded from bacterial infections and static electric charge dangers.