TY - JOUR
T1 - Effects of carbonation on the pore structure of non-hydraulic lime mortars
AU - Lawrence, R M H
AU - Mays, Timothy
AU - Rigby, Sean
AU - Walker, P
AU - D'Ayala, D
PY - 2007/6
Y1 - 2007/6
N2 - The pore structures of carbonated non-hydraulic lime mortars made with a range of different aggregates and concentrations of lime have been determined using mercury intrusion porosimetry (MIP). MIP data have been correlated with scanning electron microscopy images and other porosity data. During carbonation there is an increase in pore volume in the ~0.1 μm pore diameter range across all mortar types which is attributed to the transformation of portlandite to calcite. Also there is a monotonic increase in the volumes of pores with diameters below 0.03 μm. A model is proposed for the changes in pore structure caused by carbonation. This attributes the increase in the volume of sub 0.03 μm pores to the attachment of calcite crystals to the surface of aggregate particles, and in some cases to the surface of portlandite crystals. This phenomenon may explain the continuing presence of portlandite in mortars that, apparently, have fully carbonated.
AB - The pore structures of carbonated non-hydraulic lime mortars made with a range of different aggregates and concentrations of lime have been determined using mercury intrusion porosimetry (MIP). MIP data have been correlated with scanning electron microscopy images and other porosity data. During carbonation there is an increase in pore volume in the ~0.1 μm pore diameter range across all mortar types which is attributed to the transformation of portlandite to calcite. Also there is a monotonic increase in the volumes of pores with diameters below 0.03 μm. A model is proposed for the changes in pore structure caused by carbonation. This attributes the increase in the volume of sub 0.03 μm pores to the attachment of calcite crystals to the surface of aggregate particles, and in some cases to the surface of portlandite crystals. This phenomenon may explain the continuing presence of portlandite in mortars that, apparently, have fully carbonated.
UR - http://dx.doi.org/10.1016/j.cemconres.2007.04.011
U2 - 10.1016/j.cemconres.2007.04.011
DO - 10.1016/j.cemconres.2007.04.011
M3 - Article
SN - 0008-8846
VL - 37
SP - 1059
EP - 1069
JO - Cement and Concrete Research
JF - Cement and Concrete Research
IS - 7
ER -