TY - JOUR
T1 - Impregnation and encapsulation of lightweight aggregates for self-healing concrete
AU - Alghamri, R.
AU - Kanellopoulos, A.
AU - Al-Tabbaa, A.
N1 - © 2016 The Author(s). This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
PY - 2016/10/15
Y1 - 2016/10/15
N2 - This study investigated a technique of impregnating potential self-healing agents into lightweight aggregates (LWA) and the self-healing performance of concrete mixed with the impregnated LWA. Lightweight aggregates with a diameter range of 4–8 mm were impregnated with a sodium silicate solution as a potential self-healing agent. Concrete specimens containing the impregnated LWA and control specimens were pre-cracked up to 300 μm crack width at 7 days. Flexural strength recovery and reduction in water sorptivity were examined. After 28 days healing in water, the specimens containing the impregnated LWA showed ∼80% recovery of the pre-cracking strength, which accounts more than five times of the control specimens’ recovery. The capillary water absorption was also significantly improved; the specimens healed with the impregnated LWA showed a 50% reduction in the sorptivity index compared with the control cracked specimens and a very similar response to the control uncracked specimens. The contribution of sodium silicate in producing more calcium silicate hydrate gel was confirmed by characterisation the healing products using X-ray diffraction, Fourier transform spectroscopy, and scanning electron microscopy.
AB - This study investigated a technique of impregnating potential self-healing agents into lightweight aggregates (LWA) and the self-healing performance of concrete mixed with the impregnated LWA. Lightweight aggregates with a diameter range of 4–8 mm were impregnated with a sodium silicate solution as a potential self-healing agent. Concrete specimens containing the impregnated LWA and control specimens were pre-cracked up to 300 μm crack width at 7 days. Flexural strength recovery and reduction in water sorptivity were examined. After 28 days healing in water, the specimens containing the impregnated LWA showed ∼80% recovery of the pre-cracking strength, which accounts more than five times of the control specimens’ recovery. The capillary water absorption was also significantly improved; the specimens healed with the impregnated LWA showed a 50% reduction in the sorptivity index compared with the control cracked specimens and a very similar response to the control uncracked specimens. The contribution of sodium silicate in producing more calcium silicate hydrate gel was confirmed by characterisation the healing products using X-ray diffraction, Fourier transform spectroscopy, and scanning electron microscopy.
KW - Impregnation
KW - Lightweight aggregate
KW - Self-healing concrete
KW - Sodium silicate
UR - http://www.scopus.com/inward/record.url?scp=84981180068&partnerID=8YFLogxK
U2 - 10.1016/j.conbuildmat.2016.07.143
DO - 10.1016/j.conbuildmat.2016.07.143
M3 - Article
AN - SCOPUS:84981180068
SN - 0950-0618
VL - 124
SP - 910
EP - 921
JO - Construction and Building Materials
JF - Construction and Building Materials
ER -