Concrete Admixtures Handbook | ScienceDirect
1 - Concrete Science. This chapter discusses the important aspects of the physical, chemical, durability, and mechanical characteristics of cement paste and concrete that may be influenced by admixtures. Concrete, a composite material made with: (1) cement, (2) aggregates, (3) admixtures, and (4) water, comprises in quantity the largest of all
Superplasticizer - an overview | ScienceDirect Topics
Superplasticizers used in concrete come in four main groups: – Sulfated naphthalene formaldehyde (PNS); – Sulfated melamine formaldehyde (PMS); – Vinyl copolymers (VCPs); – Polycarboxylic ethers (PCEs). 8.2.1 Polynaphthalene sulfonates In 1930, PNS was used for the first time in the manufacture of synthetic rubber and the textile chemicals.
Super-plasticizers In Concrete: Amazon.com: Books
Super-plasticizers In Concrete. Unknown Binding – January 1, 1979. 1 rating. 1 LB bag Concrete additive-Water reducer-Super plasticizer High-performance superplasticizer for cement based construction materials Characteristics / Chemistry Free-flowing, spray dried powder of modified polycarboxylic ether. Fields of Application Superplasticizer
Use of Water Reducers, Retarders, and Superplasticizer
There are four types of superplasticizers: sulfonated melamine, sulfonated naphthalene, modified lignosulfonates and a combination of high dosages of water reducing and accelerating admixtures. Commonly used are melamine based and naphthalene based superplasticizers.
Superplasticizer
Superplasticizers ( SPs ), also known as high range water reducers, are additives used in making high strength concrete. Plasticizers are chemical compounds that enable the production of concrete with approximately 15% less water content. Superplasticizers allow reduction in water content by 30% or more.
- How a super plasticizer can be used to make concrete?
- With the use of super plasticizers, flowing concrete could be produced with the water/cement ratio as low as 0.25 or even less. The strength of such concrete was found 120 MPa (1200 kg/cm 2) or more. The use of super plasticizers also made it possible to use the fly ash, slag and silica fume to produce high quality concrete.
- What is a super plasticizer?
- Classification of Super Plasticizers 3. Uses. Super plasticizers are also called high range water reducers. They are of recent origin and relatively are more effective type water reducing admixtures. They were developed in Japan and Germany during 1960 and 1970 respectively. Chemically they are different from normal plasticizers.
- Do super plasticizers entrain air in concrete?
- As super plasticizers do not reduce the surface tension of water to a great extent, they have not found to entrain significant amount of air in concrete.
- Does PCE superplasticizer adsorb in concrete?
- The adsorption of PCE superplasticizer in a concrete mix was found to be higher than in a cement paste mixed at 700 rpm with identical mixing time, W/C and dosage. However, the relative differences of adsorbed masses of the different PCEs measured in the cement paste correlated with the results from concrete.
- Why do you need A superplasticizer?
- They help to obtain concrete with higher tolerance to slight changes in the water content, and reduce bleeding and segregation if either superplasticizer is overdosed or the water content is too high.
- How does cement chemistry affect the dispersion efficiency of superplasticizers?
- Cement chemistry can affect the dispersion efficiency of superplasticizers in various ways. One of these is through the ionic composition of the aqueous phase and in particular through the amount of soluble sulfates. The milestone paper on this subject comes from Yamada and Hanehara (2001).
