The Effect of Acid Rain on Building Materials

An experiment was conducted to find whether concentration of acid, time exposed to acid, or material most effect the deterioration of steel, brick, and commercial shingles when submerged in acid.  This set up was meant to simulate acid rain, so the two most common forms of acid rain were used: nitric (HNO3) and sulfuric acid (H2SO4).  After exposure, the material samples were dried, massed, and the percent mass change was calculated.  Each material was dropped in either nitric or sulfuric acid at each concentration (0.3 M, 0.4 M, 0.5 M) for a specified amount of time (40 min, 60 min, 80 min).  Repeat exposures were also conducted to find the effects of acid over a lengthened period of time.  A 3-Factor Design of Experiment (DOE) was used to analyze the results of each acid.  Therefore, two separate DOE’s were used to analyze the data.  The DOE for nitric acid showed that time had the single greatest effect on percent mass change, while concentration-time had the greatest combined effect.  For sulfuric acid, material and material-time had the greatest effects. According to the 3-Factor DOE test of significance, all of the factors had a significant effect on the independent variable (percent mass change) because the standard trials all had a zero percent mass change.  These results are relevant to the field of acid rain study and show that material has the greatest effect on the deterioration of a structure.  From the data, it can be reasonably stated that all aforementioned factors have a significant effect on the deterioration of building materials.            


Research Done By:

Courtney Love
Lake Shore High School

Joshua Young
Warren Mott High School