Synchrotron radiation micro computed tomography (SR Micro CT) and micro X-ray diffraction (SR Micro XRD) were used to investigate the deleterious effects of alkali-silica reaction (ASR) in mortar bars. The samples were prepared by mixing ordinary Portland cement and chert, the latter consists of quartz crystals known to be potentially alkali-silica reactive; then they are aged in a NaOH solution at 80 A degrees C according to RILEM AAR-2 for ASR to occur. A characterization of the microstructural features (cracks, voids due to dissolution, aggregate detachment) due to ASR was performed by SR Micro CT and a detailed mineralogical characterization of the weathering layer growing at the cement paste-aggregate interface was conducted by SR Micro XRD. When ASR occurs, we observe the dissolution of the quartz belonging to aggregate followed by the precipitation of new crystals of quartz. On the other hand, when ASR aging increases the quartz dissolution is almost complete and a halo diffuse scattering dominates the XRD patterns. Furthermore, the ASR generated a widespread microcracking associated with irregular voids due to aggregate dissolution and a general detachment at the cement paste-aggregate boundary is observed.

A combined synchrotron radiation micro computed tomography and micro X-ray diffraction study on deleterious alkali-silica reaction / N. Marinoni, M. Voltolini, M. Broekmans, L. Mancini, P. Monteiro, N. Rotiroti, E. Ferrari, A. Bernasconi. - In: JOURNAL OF MATERIALS SCIENCE. - ISSN 1573-4803. - 50:24(2015 Dec), pp. 7985-7997. [10.1007/s10853-015-9364-7]

A combined synchrotron radiation micro computed tomography and micro X-ray diffraction study on deleterious alkali-silica reaction

N. Marinoni;M. Voltolini;N. Rotiroti;E. Ferrari;A. Bernasconi
2015-12

Abstract

Synchrotron radiation micro computed tomography (SR Micro CT) and micro X-ray diffraction (SR Micro XRD) were used to investigate the deleterious effects of alkali-silica reaction (ASR) in mortar bars. The samples were prepared by mixing ordinary Portland cement and chert, the latter consists of quartz crystals known to be potentially alkali-silica reactive; then they are aged in a NaOH solution at 80 A degrees C according to RILEM AAR-2 for ASR to occur. A characterization of the microstructural features (cracks, voids due to dissolution, aggregate detachment) due to ASR was performed by SR Micro CT and a detailed mineralogical characterization of the weathering layer growing at the cement paste-aggregate interface was conducted by SR Micro XRD. When ASR occurs, we observe the dissolution of the quartz belonging to aggregate followed by the precipitation of new crystals of quartz. On the other hand, when ASR aging increases the quartz dissolution is almost complete and a halo diffuse scattering dominates the XRD patterns. Furthermore, the ASR generated a widespread microcracking associated with irregular voids due to aggregate dissolution and a general detachment at the cement paste-aggregate boundary is observed.
Settore GEO/06 - Mineralogia
Article (author)
File in questo prodotto:
File Dimensione Formato  
art_10.1007_s10853-015-9364-7.pdf

non disponibili

Tipologia: Publisher's version/PDF
Dimensione 4.74 MB
Formato Adobe PDF
4.74 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
Pubblicazioni consigliate

Caricamento pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/387938
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 12
  • ???jsp.display-item.citation.isi??? 11
social impact