Análise de propriedades mecânicas do concreto deteriorado pela ação de sulfato mediante utilização do UPV

Abstract

This work correlates, through mathematical models, test values of ultrasonic pulse velocity (UPV) with tests values of compressive strength and dynamic elastic modulus for concrete classes C20 and C50. The tests employ concretes of three different ages (28, 90 and 180 days), using three cement types (CP II E 32, CP III 32 RS and CP IV 32), combined with three types of coarse aggregates (gneiss, calcite and dolomite limestone), submitted to three sulfate magnesium environments (0 g/L, 10 g/L and 50 g/L of MgSO4). Complementary tests of X-ray diffraction (DRX), scanning electron microscopy (MEV) and mercury intrusion porosimetry were accomplished to corroborate with and improve analyses of correlation between UPV and compressionstrength values. Such tests inform the nature of studied concrete either justifying quantitative results other corroborating them. They also permit a more complete analysis of magnesium sulfate attack to concrete. So, through a solid statistical analysis of tests results for more than 600 specimens and all combinations of the above related variables, this work determines compressive strength and dynamic elastic modulus results, using the proposed mathematical models of correlating these mechanical properties with ultrasonic pulse velocity (UPV).