A simple suggested approach to reduce the testing time of concrete surface abrasion using ASTM C1138

The ASTM C1138 standard underwater abrasion test can be considered as the best available experimental tool to qualitatively evaluate the abrasion resistance of concrete surfaces in hydraulic structures. It introduces an accelerated test procedure to simulate the high speed motion of water and waterborne materials on concrete surfaces. However, the test period is relatively long, which is composed of 6 time steps of 12 h each, totaling a complete 72 testing hours for each sample. Thus, although of the simple test procedure and good potential to simulate real abrasion in hydraulic structures, it is difficult to perform and requires a long time if many concrete samples are needed to be compared. At the aim of investigating the possibility of reducing the total testing time of ASTM C 1138, an experimental work was conducted in this research. Three concretes with low strength (LSC), normal strength (NSC) and high strength (HSC) were tested at different rotational speeds of 800, 1200 and 1600 rpm. The test results showed that increasing the test speed from the standard 1200 rpm–1600 rpm resulted in an average increase in an abrasion weight loss of 42.6–47.0%, which encourages the possibility of reducing the total testing time by 40 % if the test is performed at a speed of 1600 rpm. The test results of this study and others from the literature showed that the relationship between the abrasion weight loss and testing time (up to 72 h) can adequately be represented using a linear correlation. The R2 values of the linear correlations of 16 different concrete mixtures ranged from 0.936 to 0.999. Based on the obtained results, a simplified modified test procedure was suggested to reduce the total testing time from 72 h to 15 h.