[article]
| Titre : |
Measuring the workability of concrete |
| Type de document : |
texte imprimé |
| Auteurs : |
Harish Agrawal, Auteur |
| Année de publication : |
2019 |
| Article en page(s) : |
p. 100-107 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Essais dynamiques
Matériaux cimentaires
Matériaux cimentaires -- Additifs
|
| Index. décimale : |
620.13 Matériaux de construction : pierre, ciment, béton, liants de |
| Résumé : |
Before we stard discussing about various construction chemicals and their applications, it is necessary to understand about the admixture and its functionality behavior along with use of various construction chemicals.
Construction chemicals are those which are used in concrete construction and repairing. Admixtures are materials that are added to concrete at some stage during its making to give the concrete new properties in the fresh and/or hardened stages besides cement, coarse and fine aggregates and water, admixtures can be called the fourth ingredient of concrete.
Chemicals are used to modify the properties of the concrete in such a way as to make it more suitable for a particular job for economy or for other purposes such as saving energy. The quantities used are very small, but they can impart the desirable qualities to the concrete that cannot be secured by other methods.
Chemicals are added to concrete for the purposes, of modifying setting times, entraining minute air bubbles, reduce water requirements of concrete mixes, increase workability, modify the capacity for fleeding, increase strength (tensile, flexural and compressive), reduce segregation, improve penetration and pump ability, reduce rate of slump loss, accelerate the rate of strength development at early ages, create slight expansion, increase the durability, decrease permeability, increase bond between old and new concrete, inhibit corrosion of embedded metals, reduce expansion produced by alkali aggregate reaction, and ease removal of forms.
It is appropriate to recognize that chemicals are no substitute for sound concrete making practices. The introduction of chemicals requires aditional care in concrete making and improved quality control.
It is appropriate to recognize that chemicals are no substitute for sound concrete making practices. The introduction of chemicals requires additional care in concrete making and improved quality control.
Mostly chemicals used are proprietary products and they are used primarily on the basis of experience or tests conducted by the manufactures. Therefore, the chemicals used should meet the applicable standards or specifications like.
1. The Indian Standard or ASTM C494
2. or the British Standard Bs5075
The amount of chemicals recommended by the manufacturer or the optimum amount determined by laboratory and field studies should be used. Many chemicals affect more than one property of concrete. Sometimes affecting desirable properties adversely. Hence careful evaluation of their effects, when singly or in combination with other chemicals, should be made by trial, mixes with that particular concrete. |
| Note de contenu : |
- PROPERTIES OF CONCRETE : Factors effecting workability
- SLUMP TEST : Concrete slump test - Principle of slump test - Slump test apparatus - Procedure of concrete slump test - Application of slump test - Conclusion - Slump test standards
- BALL-PENETRATION TEST : Advantages of the Kelly ball test - disadvantages of the Kelly ball test - Kelly ball test apparatus - Standard guidelines for the ball penetration test - Kell ball procedure
- TROWEL TEST : Advantages - Disadvantages
- STRENGTH : Types of concrete strength - Understanding grades of concrete
- BLEEDING TEST
- WATER CEMENT RATIO
- BENDING TESTS ON CONCRETE BEAMS
- Fig. 1 : Details and procedures of functional bleeding test apparatus
- Table 1 : Workability and use of concrete
- Table 2 : Measuring strength table |
| En ligne : |
https://drive.google.com/file/d/1lSJpW2kgGfadNUNDg2CrW7BG1b9I2B6Q/view?usp=share [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33647 |
in PAINTINDIA > Vol. LXIX, N° 12 (12/2019) . - p. 100-107
[article]
|
Aller sur edunet
Accueil
Measuring the workability of concrete in PAINTINDIA, Vol. LXIX, N° 12 (12/2019)
