TY - JOUR
T1 - New waste based clinkers: Belite and lime formulations
AU - Raupp-Pereira, F
AU - Ball, Richard J
AU - Rocha, J
AU - Labrincha, J
AU - Allen, G
PY - 2008
Y1 - 2008
N2 - This work describes the formulation of new belite-based (CR2) and lime-based (CR3) cementitious materials derived from industrial wastes, such as sludges (generated in the Al-anodising and surface coating industrial processes, potable water filtration/cleaning operations and in marble sawing processes) and foundry sand.
Powder mixtures were prepared and fired at different temperatures. For comparison, similar formulations were prepared with pre-treated and commercially available natural raw materials and processed in similar conditions. The thermal process was followed by differential scanning calorimetry (DSC) and high-temperature powder X-ray diffraction (HT-XRD) studies.
The CR2 clinker was found to contain belite as the main cementitious phase, the main polymorph being identified by NMR. The CR3 clinker contained common cementitious phases, such as C3A and C3S, but free lime and calcium aluminium oxide sulphates were also identified by high temperature XRD and NMR.
Then the corresponding cement was prepared and the evolution of the mechanical strength with time was evaluated. The lime-based cement obtained from wastes shows a stronger hardening character than the standard material, which tends to show dusting phenomena due to the presence of a reasonable amount of free lime (as the result of its expansive reaction with ambient moisture). Some fluxing impurities (e.g. alkalis) present in the waste materials improve the overall reactivity of the mixture and induces the combination of the lime in CR3. Raman, XPS and FIB techniques were used to fully characterise the aged cements.
AB - This work describes the formulation of new belite-based (CR2) and lime-based (CR3) cementitious materials derived from industrial wastes, such as sludges (generated in the Al-anodising and surface coating industrial processes, potable water filtration/cleaning operations and in marble sawing processes) and foundry sand.
Powder mixtures were prepared and fired at different temperatures. For comparison, similar formulations were prepared with pre-treated and commercially available natural raw materials and processed in similar conditions. The thermal process was followed by differential scanning calorimetry (DSC) and high-temperature powder X-ray diffraction (HT-XRD) studies.
The CR2 clinker was found to contain belite as the main cementitious phase, the main polymorph being identified by NMR. The CR3 clinker contained common cementitious phases, such as C3A and C3S, but free lime and calcium aluminium oxide sulphates were also identified by high temperature XRD and NMR.
Then the corresponding cement was prepared and the evolution of the mechanical strength with time was evaluated. The lime-based cement obtained from wastes shows a stronger hardening character than the standard material, which tends to show dusting phenomena due to the presence of a reasonable amount of free lime (as the result of its expansive reaction with ambient moisture). Some fluxing impurities (e.g. alkalis) present in the waste materials improve the overall reactivity of the mixture and induces the combination of the lime in CR3. Raman, XPS and FIB techniques were used to fully characterise the aged cements.
UR - http://www.scopus.com/inward/record.url?scp=39849088119&partnerID=8YFLogxK
UR - http://dx.doi.org/10.1016/j.cemconres.2007.11.008
U2 - 10.1016/j.cemconres.2007.11.008
DO - 10.1016/j.cemconres.2007.11.008
M3 - Article
VL - 38
SP - 511
EP - 521
JO - Cement and Concrete Research
JF - Cement and Concrete Research
IS - 4
ER -