Influence of Polymer Modification on Resistance of Concrete to Sulfuric Acid
J. Monteny, L. Taerwe, E. Vincke, W. Verstraete, and N. De Belie
Appears on pages(s):
concrete; durability; polymer
The resistance to a 0.5% sulfuric acid solution of six different concrete compositions with and without addition of polymer was investigated. Four different polymer types were used: a styrene-acrylic ester polymer, an acrylic polymer, a styrene butadiene polymer and a vinylcopolymer. The different concrete compositions were tested on a testing apparatus for accelerated degradation tests. The test procedure consists of an alternated submersion in a 0.5 % sulfuric acid solution and drying in air of the test cylinders (0 230 mm, height 70 mm). After each cycle, the concrete cylinders were brushed with rotary brushes to remove the weakly adhering concrete particles. Concrete degradation was measured by the change in radius of the cylinders after each cycle. The measurements were performed before and after brushing in order to determine the swelling of the cylinders due to sulfate attack formation of gypsum and ettringite- as well as the decrease of the radius due to material loss caused by brushing. The concrete composition with blast furnace slag cement showed the best resistance to the sulfuric acid attack. Comparing the four different polymer types, addition of styrene-acrylic ester increased the resistance of the concrete the most. The addition of the acrylic and the styrene butadiene caused a decreased resistance of the concrete compared to the composition without polymer addition.