ACOUSTIC-EMISSION FOR EVALUATING THE BEHAVIOR OF POLYMER IMPREGNATED CONCRETE UNDER COMPRESSIVE LOAD

Polymer impregnated cement concrete exhibits very high compressive strength: several times higher than ordinary concrete. The authors used acoustic emission to investigate fracture processes in impregnated and non-impregnated concrete subjected to uniaxial compression, to evaluate reinforcement mechanisms. The parameters were the number and character of the acoustic signals emitted for different levels of strain by impregnated and non-impregnated concrete, and the results indicate substantial differences in the fracture processes in impregnated and non-impregnated concrete. The mechanisms of reinforcement are shown to involve a reduction of strain concentration, an increase of load capacity of the cement paste matrix, a beneficiary action due to so called 'polymer bridges', and an increased bond between the cement paste and the aggregate. The acoustic emission method does not, however, provide for any quantitative evaluation of the contribution of each mechanism in the total effect of reinforcing the concrete by polymer impregnation.