Civil Engineering Reference
In-Depth Information
(a)
(b)
(c)
19.2
Production of the MgO porous blocks at the Forticrete plant
(Liska et al., 2012a): (a) mixing with manual application of the MgO,
(b) fresh blocks on the conveyer belt from the plant and (c) the
curing chamber with elevated CO
2
environment.
conditions (elevated CO
2
conditions, relative humidity, wet-dry cycling and
ambient curing) and (iii) use of additives and admixtures (mineral admixtures
and chemical admixtures) (Unluer and Al-Tabbaa, 2011, 2012; Unluer, 2012).
Porous blocks with only 4% carbonated MgO were found to achieve the
strength of the 10% PC blocks. The use of gap grading enhanced the strength
by over 60%. Ambient curing with those enhanced conditions significantly
increased the compressive strengths at 6 months but were still much lower
than those of the PC mixes. The use of mineral admixtures showed that the
incorporating of other magnesium-based compounds (brucite, silicates and
carbonates) did in some cases enhance the performance. In particular, the
inclusion of 20% of one particular heavy hydrated magnesium carbonate
led to strength increase of over 20%. Frequent wet and dry cyclic curing
also led to significant strength increase of over 30% compared to constant
high relative humidity curing (Karthika, 2011). Significant enhancement of
