STP691

    Microstructure of Concrete in Aggressive Environments

    Published: Jan 1980


      Format Pages Price  
    PDF Version (424K) 16 $25   ADD TO CART
    Complete Source PDF (15M) 16 $83   ADD TO CART


    Abstract

    All the constituents of concrete can be attacked. Some degradations occur after a long period of time. So, it is important to know the chemical and physical mechanisms of the corrosion and the behavior of built structures. In our studies on the durability of concrete, chemical and technological tests have been completed by microstructure examination with scanning electron microscopy and X-ray diffraction. In the present stage of our research into the attack of concrete by seawater, several factors can be noted. The formation of expansive ettringite is related to the content, the crystalline form, and the granularity of tricalcium aluminate. The carbonation reaction transforms ettringite into thaumasite. The dissolving of lime-rich compounds like hydrated silicates C-S-H brings about their progressive transformation into Ca-Mg silicates. Some aggregates have been found to have reacted with alkalis. A dense concrete with a high cement content will offer a good resistance to chemical and physical attacks.

    Keywords:

    microstructure, concrete, thaumasite, durability, seawater, ettringite, alkalis reaction, sand-cement, scanning electron microscope, X-ray diffraction, building materials, durability


    Author Information:

    Regourd, M
    Doctor of Physical Science, Engineer CNAM and Engineer, Centre D'Etudes et de Recherches de L'Industrie des Liants Hydrauliques, Paris,

    Hornain, H
    Doctor of Physical Science, Engineer CNAM and Engineer, Centre D'Etudes et de Recherches de L'Industrie des Liants Hydrauliques, Paris,

    Mortureux, B
    Doctor of Physical Science, Engineer CNAM and Engineer, Centre D'Etudes et de Recherches de L'Industrie des Liants Hydrauliques, Paris,


    Paper ID: STP36064S

    Committee/Subcommittee: E06.11

    DOI: 10.1520/STP36064S


    CrossRef ASTM International is a member of CrossRef.