Title:
Hyaloclastite based Natural Pozzolanic Material Performance
Author(s):
Romeo Ciupeca,
Publication:
Web Session
Volume:
ws_S22_Ciupeca.pdf
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
3/28/2022
Abstract:
Hyaloclastite is formed by magma that extrudes into a water rich environment causing a rapid quenching of the magma, which prevents lava crystallization generally resulting in fractured lava with high amorphous content. When Hyaloclastite is ground into a fine powder, the resulting natural pozzolan can be used as a replacement for fly ash, slag, silica fume or metakaolin. Coarser grinding gives properties similar to fly ash. Finer grinding significantly outperforms fly ash and slag, with properties equivalent to those of concretes with silica fume or metakaolin, at a lower cost. The ground hyaloclastite provides improved ASR resistance, reduced chloride permeability, reduced capillary absorption, and enhanced strength. Though it provides reductions in chloride diffusion similar to silica fume and metakaolin, its aging factor is similar to fly ash and slag resulting in enhanced properties over time. Air entrainment freezing and thawing performance are similar to control mixes at the same w/cm.