ZIBO JIANHUA BUILDING MATERIALS CO.,LTD
official web site:www.jianhua-pce.com
0086-533 7111578

Products

Knowledge
Home > Knowledge > Content

Using Admixtures to Improve Chemical Resistance of Concrete

Source: | Updated: Feb 02, 2016

If concrete will be exposed to aggressive chemicals in a natural or an industrial environment, what role can admixtures play in improving concrete performance? Admixtures significantly improve performance for some, but not all, exposures.

LOW PERMEABILITY KEY TO CHEMICAL RESISTANCE

Production of high-quality, low-permeability concrete is the first line of defense against chemical attack. Admixtures reduce concrete permeability in several ways. They can: permit the use of a lower water-cement ratio; make concrete easier to consolidate; convert soluble hydration products to insoluble ones; fill voids within the cement-paste matrix; and reduce shrinkage, thus reducing cracking potential.

LEACHING

Leaching is a mild form of distress that occurs when water dissolves components in the concrete. Admixtures can help control leaching through two mechanisms: reducing permeability and converting the soluble calcium hydroxide into insoluble calcium silicate hydrate (CSH).

SULFATE ATTACK

Concrete that's exposed to sulfates, usually in soil or groundwater, can disintegrate in only a few years due to physical or chemical reaction, or both. Silica fume is very effective in improving sulfate resistance by converting calcium hydroxide to CSH. Air-entraining admixtures improve sulfate resistance, primarily because air entrainment permits a reduced water-cement ratio that decreases permeability.

ACID ATTACK

Because no portland-cement concrete is totally immune to acid attack, admixtures can be used only to slow the rate of deterioration. Water-reducing admixtures, including superplasticizers, reduce the water-cement ratio and thus permeability.

Feedback
Contact Us
Address: Wangzhu Industrial Zone, Linzi District, Zibo City, Shandong, China
Tel: 0086-533 7111578
Fax: 0086-533 7114227
E-mail:sales@jianhua-pce.com
Home | About Us | Products | News | Knowledge | Contact Us | Feedback | Mobile | XML