UNI-MB - logo
UMNIK - logo
 
(UM)
  • The effect of delayed ettringite formation on fine grained aerated concrete mechanical properties
    Lubej, Samo, 1958- ...
    Delayed ettringite formation (DEF) is a chemical reaction with proven damaging effects on the mechanical properties of hydrated cementitious composite (concrete). Ettringite crystals can cause cracks ... and the widening of cracks due to pressure on the crack walls caused by the positive volume difference in the reaction. In this paper, we investigated the potential to utilise the positive volume difference in DEF in order to improve the mechanical properties of hydrated fine grained aerated concrete. Fine dispersed crystallisation nuclei, achieved by adding air-entraining agent (AEA) and by short vibration of specimens, are presented as the main requirement for such improvements. Control tests of expansion and mechanical properties were performed on samples of concrete with and without AEA by inducing DEF. The microstructure of fine grained aerated concrete was examined with an optical microscope and scanning electron microscope. We found that the controlled DEF, which is guaranteed by adding AEA and with the formation of uniformly dispersed air bubbles, which are crystallisation sites for ettringite crystals, improves the mechanical properties. The specimens with induced DEF were measured and found to have a 6.8% increase of compressive strength.
    Vir: Science and engineering of composite materials. - ISSN 0792-1233 (Vol. 23, iss. 3, May 2016, str. 325-334)
    Vrsta gradiva - članek, sestavni del
    Leto - 2016
    Jezik - angleški
    COBISS.SI-ID - 18391830

    Povezava(-e):

    http://www.degruyter.com/view/j/secm.ahead-of-print/secm-2012-0107/secm-2012-0107.xml
    DOI

vir: Science and engineering of composite materials. - ISSN 0792-1233 (Vol. 23, iss. 3, May 2016, str. 325-334)

loading ...
loading ...
loading ...

Vnos na polico