Consolidation of weathered limestone using nanolime

Abstract

Limestone sourced from Salisbury Cathedral and Bath Abbey (UK) was treated with commercially available nanolime of concentration 25 g/l. The response of the stones to the treatment was studied using a variety of analysis techniques including optical microscopy, electron microscopy, drilling resistance measurement and mercury intrusion porosimetry. Weathered and non-weathered surfaces of both types of stones were compared. All the specimens were characterised before and after the treatment to determine any changes in their properties caused by their weathering and by the treatment itself. Results show that the degradation processes of the stones strongly affect their interaction with nanolime consolidation treatments. Drilling resistance measurements of treated and untreated samples were compared. After 20 days significant increases in sub-surface drilling resistance was observed in the non-weathered Bath stone and a small increase in the weathered Bath stone after 6 months was also noted. Both weathered and nonweathered Chilmark stone showed an increase in drilling resistance after 6 months, however at 20 days this was most evident in the samples treated with nanolime in isopropanol as opposed to ethanol.

Environmental performance of nano-structured Ca(OH)2/TiO2 photocatalytic coatings for buildings

“…Figure 2a shows the structure of Bath stone with a distributed set of clusters composed by Oolites that makes the stone's structure very porous. Bath stone was previously characterized by mercury intrusion porosimetry (MIP) using a Micrometrics AutoPore III [42]. The majority of the pores were around 10 and 0.1µm in diameter, and the macro pores were over 100µm and micropores (between Oolites) which are between 10 and 1µm in diameter.…”

Optimization of drilling resistance measurement (DRM) user-controlled variables

“…One of the very few on-site techniques that is appropriate for the assessment of the mechanical properties of modern and historic construction materials is drilling resistance measurement (DRM) [1,2]. The technique is based on the use of a portable drilling machine capable of measuring the drilling resistance and penetration depth of a drill bit, usually between 3 and 7 mm in diameter.…”

A Review of the Assessment Tools for the Efficiency of Nanolime Calcareous Stone Consolidant Products for Historic Structures

“…Recently, alkoxysilanes were proven to function in a deteriorating way for calcareous stones forming isolated aggregates within the pores of calcareous stones, whereas, for siliceous stones, gelling of the sols created a continuous film, closing the pores ( Figure 6) [7]. A number of experimental results were provided including attenuated total reflection infrared spectroscopy (ATR-FTIR), 29 Si magic-angle spinning (MAS) spectroscopy, pH measurements, scanning electron microscopy (SEM). attenuated total reflection infrared spectroscopy (ATR-FTIR), 29 Si magic-angle spinning (MAS) spectroscopy, pH measurements, scanning electron microscopy (SEM).…”

“…A number of experimental results were provided including attenuated total reflection infrared spectroscopy (ATR-FTIR), 29 Si magic-angle spinning (MAS) spectroscopy, pH measurements, scanning electron microscopy (SEM). attenuated total reflection infrared spectroscopy (ATR-FTIR), 29 Si magic-angle spinning (MAS) spectroscopy, pH measurements, scanning electron microscopy (SEM). This paper focused on the nanolime treatments of calcareous stones, i.e., limestones, marbles, dolostones, and calcarenites.…”