Experimental determination of recycled aggregates concrete carbonation

The construction industry is one of the main sources of pollution, starting with the extraction of raw materials and the demolition of existing buildings, providing huge amounts of CDW (construction and demolition waste). Concretes with recycled aggregate have higher porosity than those achieved with natural aggregates, (20-30% higher) which can influence the carbonation depth. A typical C16 / 20 concrete class has been studied with natural aggregates, replacing the various granulometric fractions with recycled aggregates. The 100x100x100mm cube specimens were stored for 28 days in water, tested (physicomechanical characteristics) and subjected to accelerated carbonation experiments. After being stored for 60 days under accelerated carbonation conditions, the specimens were cleaved to determine the carbonation depth after phenolphthalein testing of the faces in the splitting zone, measuring the minimum and maximum carbon dioxide penetration values. Correlation was made between the compressive strengths obtained for the studied specimens and the carbonation depth after the accelerated carbonation experiments in a protected environment - 50% carbon dioxide concentration, temperature 25 ° C and humidity 75-80%