Study on Rapid Determination Method of Alkali-Aggregate Reaction by Electrochemical Technique
Kazuo SEKINO and Naomitsu TSUYUKI
Abstract:This study was conducted to grasp the possibilities of a method for determining alkali-aggregate reaction rapidly, through the use of potential difference between two aqueous solutions separated by a cation exchange membrane. The rhyolite powder(75`150ƒÊm)was used in the test samples. The membrane potential according to the equation for theory(Goldman equation) was calculated by substitution of the analysis value of Na, K and Si concentrations at aqueous electrolyte solutions.The results obtained were as follows : (1)The potential difference was measured with gPositive(+)h and gNegative(-)h values at testing periods of 3`15minutes, by the use of gInnocuoushandgDeleterioushpowder interpreted according to ASR chemical method(JIS A 1145), respectively. (2)The potential difference was highly correlated with Rc/Sc ratio tested to ASR chemical method. (3) The membrane potential according to the theory equation was calculated for gPositive(+)h and gNegative(-)h value, respectively, as in the case of the potential difference by the membrane. (4)From these results, it was recognized that the method of test for alkali-aggregate reaction by electrochemical technique was able to judge rapidly, and held great promise at the site of mine. Key Words:Alkali-aggregate reaction, Potential difference, Membrane potential, Cation exchange membrane, ASR Chemical method, ASR mortar bar method, ASR rapid method, Electrochemical technique