Utilização dos testes estatísticos de Kolmogorov-Smirnov e Shapiro-Wilk para verificação da normalidade para materiais de pavimentação

Abstract

For pavement materials evaluation, it is common to treat laboratorial test data with classical statistical concepts,considering that a data set has a normal distribution, and therefore using the parameters average and standard deviation. The present workaims to verify if the normal distribution can be applied for the results of some tests, such as bulk specific gravity, apparent specific gravity and absorption for coarse aggregates, bulk specific gravity and air voids for hot mixture asphalt samples. The Kolmogorov-Smirnov (K-S) e Shapiro-Wilk (S-W) tests were used with the SPSS. Each test was carried out at least 30 times by the same operator usingthe same equipment. There was convergence between the two normality tests for five of the six parameters.Then, the tests were also performed by nine different laboratories using similar samples; and only S-W test was used. These statistical analyses support the decision about the statistical tools used in the Interlaboratory Program of Aggregates and Asphalt Mixtures of the North-Northeast Asphalt Network