Α Nano Approach to Consolidation of Degraded Historic Lime Mortars

Abstract

This paper presents a comparative study of the effects of calcium hydroxide based agents on consolidating a lean lime mortar. In the first part, it describes the properties and characteristics of CaLoSiL® – a new stone strengthener based on colloidal suspensions of lime nanoparticles in various solvents. It further summarizes the results of recent tests on the influence of applying nano-agents based on colloidal calcium hydroxide dispersed in ethanol or isopropyl alcohol (CaLoSiL®), and compares them with the effects of lime water and with a traditional barium hydroxide treatment. The tests were carried out on non-standard test specimens fabricated from a lean mortar (1:9) and developed specially for the purpose of testing the relatively low strengthening effects that are typical for lime water consolidation. The comparison presented in this paper is based on the mechanical characteristics of consolidated lime mortar.

Characterization of vaterite synthesized at various temperatures and stirring velocities without use of additives

“…CaCO 3 , as the main constituent of limestone rocks, has got significant application in the building industry. In the recent years, lime, which is produced from them, has become an important material in the cultural heritage conservation for designing repair mortars compatible with the existing historic materials [7,8].…”

Calcium hydroxide nanosols for the consolidation of porous building materials - results from EU-STONECORE

“…In the frame of STONECORE a wide range of materials were successfully treated for consolidation with the different CaLoSiL nanosols [5][6][7]. This paper concentrates on two conservation tasks: consolidation of mortar and filling of cracks and gaps [8].…”

Nanotechnologies in Cultural Heritage - Materials and Instruments for Diagnosis and Treatment

“…Sandstones are the result of sedimentation of sand together with silica or calcium carbonate; the silica in the tiles may have the same adverse effect encountered at the granite. Both sedimentary rocks-limestone and sandstone-are easier to cut than granite, which has made them quite often used in the masonry of historical buildings [23,24]. On the Romanian territory, there are many masonry made of siliceous sandstone or calcareous sandstone, the first being those with higher compressive strength.…”

“…The tensions in the surfaces that delineate the pores due to the salts crystallized here, known as "stone efflorescence," represents a great danger for the durability of a historical structure. The most common salts in the efflorescence phenomenon of masonry are sulfates, carbonates and nitrates (sodium, magnesium, calcium, potassium), generated from the atmospheric pollutants (SO 2 , NO 2 and CO 2 ), which are transformed in (HNO 3 , H 2 SO 4 and H 2 CO 3 ) in contact with the mortars [24,29].…”