Effect of metakaolin addition on capillary absorption and carbonation of concrete

For the capillary absorption test, the samples were oven dried, weighed, immersed in water for periods of 1, 2, 3 and 24 hours. After each period, the samples were dried and weighed, and these values were used to obtain the Abrams curve.

The carbonation test was carried out after curing the specimens in a moist chamber, standardizing the humidity for two hours and remaining in the carbonation chamber for 30 days with 5% CO2 at 23±2°C. After this period, the specimens were cut in half, sprayed with a solution of phenolphthalein and an image analysis was performed. For samples prepared with CPIII cement with one or two aggregates, the MK addition increased the capillary absorption.