Table of Contents
What is the role of a water reducing admixture in concrete?
Water-reducing admixtures are primarily used to reduce the water-cementitious content of concrete, thus increasing strength. In some cases, they can be used to increase the workability or slump of the concrete providing for easier placement.
What is a water reducing agent?
[′wȯd·ər ri‚düs·iŋ ‚ā·jənt] (materials) An additive for freshly mixed mortar or concrete for increasing workability without increasing water content, or for maintaining workability with a reduced amount of water.
What are water reducing admixtures examples?
Water-Reducing Admixture
- Geopolymer.
- Bottom Ash.
- Compressive Strength.
- Recycled Concrete Aggregate.
- Silica Fume.
- Superplasticizers.
- Recycled Aggregate.
- Superplasticizer.
Why is pozzolana added to cement?
What does a pozzolan do in the concrete? A. Pozzolans reduce bleeding because of fineness; reduce the maximum rise in temperature when used in large amounts (more than 15% by mass of cementitious material) because of the slower rate of chemical reactions; which reduce the rise in temperature.
Is water reducing agent?
In the presence of a strong electron acceptor (strong oxidizing agent), water serves as a reducing agent. Water is rather weak as an oxidizing or as a reducing agent, however; so there are not many substances which reduce or oxidize it. Thus it makes a good solvent for redox reactions.
What are plasticizers Sanfoundry?
What are plasticizers? Explanation: The organic substances or combinations of organic and inorganic substances, which allow a reduction in water content for the given workability, or give higher workability at the same water content. 2.
Why are water reducing admixtures used?
Water-reducing admixtures usually reduce the required water content for a concrete mixture by about 5 to 10 percent. Consequently, concrete containing a water-reducing admixture needs less water to reach a required slump than untreated concrete. The treated concrete can have a lower water-cement ratio.
Does plasticizer weaken concrete?
Adding an excessive amount of plasticizer will result in excessive segregation of concrete and is not advisable. Depending on the particular chemical used, use of too much plasticizer may result in a retarding effect.
Why is superplasticizer added to concrete?
Superplasticizers are used to increase the fluidity of concrete without adding excess water. These molecules physically separate the cement particles by opposing their attractive forces with steric and/or electrostatic forces, as explained in Chapter 11 (Gelardi and Flatt, 2016).
Is pozzolana a cement?
properties. Pozzolanic cements are mixtures of portland cement and a pozzolanic material that may be either natural or artificial. The natural pozzolanas are mainly materials of volcanic origin but include some diatomaceous earths. Artificial materials include fly ash, burned clays, and shales.