Experimental tests on the underwater abrasion of Engineered Cementitious Composites

The abrasion of Engineered Cementitious Composites (ECC) due to waterborne materials in hydraulic structures was investigated using the ASTM C1138 abrasion test method. The test specimens were divided into two groups, the first was directed to study the effect of the PVA fiber content, while the second investigated the effect of the ECC covering layer thickness. The tests were conducted at ages of 3, 7 and 28 days. The test results showed that the abrasion resistance increases as PVA content increase. At an age of 28 days, incorporating low PVA contents (0.5% and 1.0%) increased the abrasion resistance by approximately 20%, while the inclusion of high PVA contents (1.5% and 2.0%) improved the abrasion resistance significantly with percentage improvements ranging from 50 to 95%. The percentage abrasion weight losses after 72 testing hours at this age were 7.6, 5.9, 4.7, 3.6 and 2.4% for fiber contents of 0, 0.5, 1.0, 1.5 and 2.0%, respectively. The test results also showed that covering of normal concrete with 1 cm layer of ECC is not effective during the early age of this material, while a layer of 3 cm thickness showed good abrasion resistance at early and mature ages.