What is "Porphyry" in concrete mix design?

In terms of Concrete Mix Design is "Porphyry" a trade name for a specific stone or a type of stone with certain properties? This would be specific to UPHC Concrete mix. I would like some assistance in understanding this term in relation to Concrete mix design.

If I were to be mixing a UHPC and had all the components, would I use "Porphyry" as the Aggregate or a stone with similar properties to a "Porphyry"

Update:

I am familiar with Porphyry as a stone name, its properties etc, but in terms of Concrete Mix Design it seems that this is a genaric term. Anyone familar with Concrete engineering and its generic terms?

3 Answers

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  • MOZ
    Lv 7
    9 years ago
    Favorite Answer

    It is a specific type of stone with properties of durability, hardness, impermeability, chemical resistance, freeze/thaw resistance, green attributes and long-term affordability.

    It either is or isn't porphyry. There are no stones "with similar properties."

  • 9 years ago

    Yes, there is a specific stone named Porphyry, but that's not what you are asking about. Also, there are many porphyritic rock with similar properties as Porphyry.

    Porphyry (Proper name of a certain rock)

    porphyry (igneous rock with a large degree of difference between particle sizes)

    "porphyry" in terms of concrete design refers to the texture of an igneous rock with large crystals and smaller ones. There are many many rock with these qualities, to many to list all. This term is commonly used when a particle's size, strength and geometry are fundamental to the strength/cohesion of a matrix.

    "porphyritic aggregate" is generally the term used in UHPC Concrete design or the shortened version "porphyry". Usually this term is followed by a particle size. For example porphyry 1/3 referring to a matrix of particles with a size of 1mm and 3mm. or between 1 and 3 mm.

    Source(s): http://en.wikipedia.org/wiki/Porphyry_(geology) other sites not listed
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