Use of Secondary Crystallization and Fly Ash in Waterproofing Materials to Increase Concrete Resistance to Aggressive Gases and Liquids

Table 5

Description of aggressive environments.

Environment		Concentration	Relative humidity	Temperature
Gaseous	CO2	Low: 1-2%	60 ± 10%	21 ± 2°C
	CO2	High: 5–10%
	SO2	High: 5–10%
Liquid	SO4^2−	Na2SO4·10 g/l		21 ± 2°C
	SO4^2−	Na2SO4·34.6 g/l
	Cl^−	NaCl·100 g/l
Real outdoor environment

The real environment shows the effects of climatic influence on samples stored outdoors where during the exposure, the temperatures alternate ranging from −15.9°C to + 34.8°C. Samples were also exposed to irregular precipitation, direct sunlight, air pollution, and biological agents.