Concrete Admixtures and the Environment

Concrete Admixtures and the Environment

Concrete admixtures are liquid or powder additives. They are added to the concrete mix in small quantities to meet specific requirements:

·     To increase the durability

·     To improve the workability

·     To change the setting or hardening reaction of the cement

The effect of admixtures is always to improve the concrete. In quantity terms, super plasticizers (high range water reducers) and plasticizers (water reducers) as a group make up about 80% of all of the admixtures used today.

How much do concrete admixtures leach, biodegrade or release fumes?

Super plasticizers should be non-toxic, water-soluble and biodegradable.

Tests on pulverized concrete specimens show that small quantities of super plasticizers and their decomposition products are leachable in principle. However, the materials degrade well and do not cause any relevant ground water pollution. Even under the most extreme conditions, only small quantities of organic carbon leaches into the water.

·     Conclusion of test: The air is not polluted by super plasticizers.

To summarize: How environment-friendly are super plasticizers?

Concrete admixtures are appropriate for their application and when correctly used are harmless to man, animals and the environment.

The technical benefits of super plasticizers for clients and construction professionals outweigh the occurrence of low, controllable emissions during use. Concrete admixtures merit being rated environment-friendly because they create negligible air, soil or ground water pollution.

See the following publications:

·     “Environmental Compatibility of Concrete Admixtures” Report by the Association of Swiss Concrete Admixtures Manufacturers (FSHBZ)

·     EU Project ANACAD Analysis and Results of Concrete Admixtures in Wastewater Final report BMG Engineering AG Zürich