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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.
What is the use of pozzolanic cement?
Typically pozzolans are used as cement replacements rather than cement additions. Adding pozzolans to an existing concrete mix without removing an equivalent amount of cement increases the paste content and decreases the water/cement ratio. In other words, adding more pozzolans to a mix changes the mix proportions.
How is Pozzolana cement made?
Pozzolana, also spelled pozzuolana, or pozzolan, hydraulic cement discovered by the Romans and still used in some countries, made by grinding pozzolana (a type of slag that may be either natural—i.e., volcanic—or artificial, from a blast furnace) with powdered hydrated lime.
What are the advantages of pozzolanic materials?
The advantages of using pozzolans in concrete include the following: (1) material cost reduction when a part of the cement is replaced by pozzolans, which are low cost (with some of them being natural or industrial by-products/wastes) and pollution free; (2) environmental cost reduction in relation to reducing the.
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.
Which is not pozzolanic materials?
Which of the following is not a pozzolanic material? Explanation: Pozzolans are silicate based materials that form cementitious materials. Fly ash, silica fumes and slag are composed of oxide of silicon. Cinder is a coal residue.
Where is PPC cement used?
PPC is special blended cement useful in general construction work and is especially suitable for applications in aggressive environmental conditions. It can be confidently employed in construction of hydraulic structures, marine works, mass concreting such as dams, dykes, retaining walls foundations and sewage pipes.
What is the full form of PPC cement?
Portland Pozzolana Cement (PPC) is manufactured by a combination of pozzolanic materials. Pozzolana is an artificial or natural material that has silica in it in a reactive form. Along with pozzolanic materials in specific proportions, PPC also contains OPC clinker and gypsum.
What is difference between OPC cement and PPC cement?
Portland Pozzolana Cement is a variation of Ordinary Portland Cement. Pozzolana materials namely fly ash, volcanic ash, are added to the OPC so that it becomes PPC. PPC is cheaper than OPC. PPC has low initial setting strength compared to OPC but hardens over a period of time with proper curing.
What are pozzolanic materials?
Pozzolanic materials are siliceous and aluminous materials, possessing little or no cementitious value by themselves, but in finely divided form and in the presence of moisture react chemically with calcium hydroxide liberated on hydration of cement at ordinary temperature to form compounds, possessing cementitious.
Can Pozzolans react without cement?
The pozzolanic reaction converts a silica-rich precursor with no cementing properties, to a calcium silicate, with good cementing properties.
What are pozzolanic properties?
A pozzolan is a siliceous or siliceous and aluminous material that in itself possesses little or no cementitious value but will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form compounds having cementitious properties.
Which concrete is used in Pozzolans?
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.
What are the advantages of Portland Pozzolana cement?
Portland pozzolana cement (PPC) has following advantages when concrete is in its hardened state. Compressive Strength & Rate of Strength Gain. Modulus of Elasticity. Bond of Concrete to Steel. Heat of Hydration. Reduced Shrinkage. Permeability.
What is Poisson’s ratio for concrete?
The relation between transversal deformation and the longitudinal direction is called Poisson’s ratio. The static Poisson’s ratio normally for hardened concrete varies between 0.15-0.25 [2]. For a fluid like material, the Poisson’s ratio is 0.5. Fresh concrete can be regarded as a fluid.
Is Lime a pozzolanic material?
It is based on an ancient cement binding technology that combines naturally occurring pozzolanic materials – such as volcanic ash – with slaked lime to produce concrete that can be hydraulically set.
Is rice husk ash pozzolanic material?
Rice husk ash as a pozzolanic reactive material can be used to improve surface area of transition zone between the microscopic structure of cement paste and aggregate in the high-performance concrete. These results drastically benefits durability and resistance of concrete constructions and their service life.
Which ingredient gives Colour to the cement?
Iron oxide is present about 0.5 – 6.0 % in cement, which provides colour, hardness and strength to the cement.
Which cement is better 43 grade or 53 grade?
The fineness in cement generates early gain in strength, but along with high heat of hydration. OPC 43 grade cement is generally used for non-structural works like plastering flooring etc. Whereas OPC 53 grade cement is used in the projects which require higher strength like concrete bridges, runways RCC works etc.
Which type of cement is best?
Which is the best cement for house construction? Ordinary Portland Cement (OPC) 43 Grade Cement: It is used majorly for wall plastering works, Non-RCC structures, pathways etc. Ordinary Portland Cement (OPC), 53 Grade Cement: Portland Pozzolana Cement (PPC): Portland Slag Cement (PSC): White Cement:.
Which cement is best for roof?
Use of OPC 53 grade and PPC ( Portland pozzolana cement) is the best cement for roof dhalai and for all type of RCC structure like footing,slab, beam and column.
Is cement code tested?
IS: 4031 – chemical analysis and tests on cement. IS: 456; 10262; SP 23 – codes for designing concrete mixes. IS: 1199 – methods of sampling and analysis of concrete. IS: 516BXB JWJJS– methods of test for strength of concrete.
Can we use PPC cement for RCC work?
Both OPC and PPC cements are good for construction of concrete slab. PPC is used where possibilities of sulphate attack is higher as it has good sulphate resistance compared to OPC. Also pozzolana Portland cement is cheaper than ordinary Portland cement.
Which cement is best for plaster?
There are three main Cement Grades from which you can choose. These are Ordinary Portland Cement (OPC), Portland Slag Cement (PSC) and Portland Pozzolana Cement (PPC) available in the market. OPC is available in two grades — 43 and 53. Both grades are considered best for plastering work.
