Civil Engineering Reference
In-Depth Information
and MgO (0.02-23.4%) content, as well as the presence of heavy metals
such as chromium, copper and zinc at concentrations of under 2700,
5500 and 10 000 mg/kg, respectively. These elements have an adverse
effect on reaction kinetics, microporosity, fresh and hardened concrete
properties and durability (Monzó et al., 1999; Bai et al., 2003; Cyr et
al., 2007; Jamshidi et al., 2012).
∑
Electric arc furnace steel slag (EAFS
) generated during steel manufacture-
related mining and refining. In the late 1990s, Europe generated 12 Mt/
year of steel slag, 35% of which was stockpiled. That slag, primarily
black slag, is known to have no pozzolanic properties and hence is
primarily recycled as an aggregate for concrete and road building (Frías
and Sánchez de Rojas, 2004; Frías et al., 2010b). Nonetheless, a recent
study (Muhmood et al., 2009) showed that it may be recycled as an active
addition to cement if subjected to prior remelting and water quenching,
after which its mechanical behaviour is similar to performance in the
control.
∑
Palm oil fuel ash (POFA
), obtained when palm shell oil, is used as a
fuel to generate electric power (Borrachero et al., 2007). Production is
estimated at 1.1 t per crop hectare which, after incineration, generates
ash (5% of the waste) rich in silica (58%) and potassium oxide (8.3%)
and with excellent pozzolanic properties (Tangchirapat et al., 2007).
Research has shown that replacing ordinary Portland cement (OPC)
with up to 20% of (finely ground) POFA raises concrete compressive
strength, although at higher percentages its inclusion in cement lowers
strength values compared to the reference concrete.
5.7 Acknowledgements
The research discussed in this chapter was funded by Spanish ministries
(Project refs: MAT2003-06479-CO3; CTM2006-12551-CO3; MAT2009-
10874-CO3), the Spanish National Research Council (CSIC) (Project
refs: 200460E617 and 2003CU0009) and the following companies: Elmet,
Ferroatlántica (Ferroalloys Division), Repsol, Altuna and Uria, Holmen Paper
Madrid and Maicerías Española.
5.8 References
Armesto L., Bahillo A., Veijonen K., Cabanillas A., Otero J., (2002), 'Combustion
behaviour of rice husk in a bubbling fluidised bed'.
Biom Bioe
,
23
, 171-179.
Bai, Y., Bashaer, P.A., (2003), 'Influence of furnace bottom ash on properties of concrete'.
Proceedings of the Institution of Civil Engineers
.
Struc Build
,
156
, 85-92.
Bai J., Chaipanich A., Kinuthia JM., O'Farrell M., Sabir BB., Wild S., Lewis MH., (2003),
'Compressive strength and hydration of waste paper sludge ash-ground granulated
blastfurnace slag blended pastes'.
Cem Concr Res
,
33
, 1189-1202.
