SUPERPLASTICIZERS - Penn State College of Engineering
The dosage rate ranges from 6 – 25 oz. for every 100-lb of cement. The lower dosage will provide the Type A (Water Reducing) and mid to high dosage will provide Type F. Current product of superplasticizers has an extended slump retention time twice than the conventional one (up to two hours).
Use of Water Reducers, Retarders, and Superplasticizers.
The use of WRA is defined as Type A in ASTM C 494. WRA affects mainly the fresh properties of concrete by reducing the amount of water used by 5% to 12% while maintaining a certain level of consistency, measured by the slump as prescribed in ASTM C 143-90. The use of WRA may accelerate or retard the initial setting time of concrete.
SP-354: Superplasticizers and Other Chemical Admixtures
of the chemical admixtures, cement, and concrete industries to exchange information and delineate new areas of needed research. The scope of this conference was expanded to include chemical admixtures other than superplasticizers. Proceedings of the conference were published as ACI SP-119.
Superplasticizer: Types, Advantages & Disadvantages
Superplasticizers are mainly used in pumping concrete, casting heavily reinforced members and precast elements of concrete. Advantages of Superplasticizer: 1. Superplasticizers reduces the water content. 2. It reduces the cement content. 3. Also, increases the workability of concrete. 4. It reduces the permeability of concrete. 5.
Mix Design With Superplasticizers - Civil Engineering Portal
The Superplasticizers are broadly classified into four groups: sulfonated melamine formaldehyde condensate (SMF), sulphonated naphthalene formaldehyde condensate (SNF), modified lignosulphonate (MLS) and others including sulphonic acid ester, polyacrylates, polystryrene sulphonates, etc.
- What is a superplasticizer admixture?
- Superplasticizers belong to a class of water reducers chemically different from the normal water reducers and capable of reducing water contents by about 30%. The admixtures belonging to this class are variously known as superplasticizers,” “superfluidizers,” “superfluidifiers,” “super water reducers,” or “high range water reducers.”
- What are the advantages and disadvantages of superplasticizers?
- The advantages of superplasticizers include: (1) production of concrete having high workability for easy placement, and (2) production of high strength concrete with normal workability but with a lower water content.
- Which Admixtures are compatible with superplasticizers?
- Generally retarders, water reducers, accelerators, and air-entraining agents have been found to be compatible with superplasticizers. In some instances, the resulting effects are synergis- tic. It is, however, essential that each admixture combination should be evaluated before it can be practically utilized.
- What is the maximum tensile strength of a superplasticizer?
- The maximum split tensile strength at 28 days of testing for all cases was found to be 29.09 MPa—SNF based, 30.72 MPa—SMF based, and 31.23 MPa—PC-based admixture, respectively, at 1.5% of dosage (Fig. 6). Therefore, the effect of superplasticizers mainly influences the workability of concrete rather mechanical properties.
- What are the properties of a superplasticizer?
- The most important property of a superplasticizer is its ability of dispersing the cement particles. Electron microscopic examination reveals that in water suspensions of cement, large irregular agglomerates of cement particles form. By the addition of a superplasticizer, the material is dispersed into small particles.
- Are PC-based admixtures more prominent than sulphonated superplasticizers?
- Based on the observation, it is recommended that PC-based admixtures are more prominent than sulphonated superplasticizers in terms of water reduction, workability, and strength aspects. Discover the latest articles, news and stories from top researchers in related subjects.
