Quantifying 450 years of limestone weathering induced by salt crystallization on fortifications in Malta and Gozo

The national soil monitoring network (Nabo) consists of 105 sites across Switzerland, 28 of which are located in forests. After 25 years already seven forest sites (25%) were more or less damaged by storms. Two of them had to be abandoned for a decade to recover. Concerning precautionary soil protection the legal guide value is exceeded at three forest sites for cadmium and at one site also for chromium. These sites are all based on Jurassic limestone, and it is well known that residuals of limestone weathering can be rich in cadmium. Hence, the enrichment is supposed to be of geogenic origin. In the Canton Ticino the top soil at Novaggio site exceeds the guide value for lead. Here, anthropogenic origin is very likely. The analysis of the organic pollutants PAH and PCB in the third sampling campaign revealed moderate concentrations with a maximum lower than or equal to ⅔ of the corresponding guide value. Based on the results of the first four sampling campaigns it can be concluded that only small changes in the measured heavy metal concentrations in the top soils at the 28 Nabo sites were found. The most dynamic element is lead. Most of the concentrations are far below the guide values, the same holds for the organic pollutants PAH and PCB.

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Natural stone test methods. Determination of resistance to salt crystallization

10.3403/01663694 ◽

1999 ◽

Keyword(s):

Test Methods ◽

Natural Stone ◽

Salt Crystallization

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Salt crystallization pressure as a new method to obtain micro and nanocellulose

Cellulose ◽

10.1007/s10570-021-03785-y ◽

2021 ◽

Vol 28 (7) ◽

pp. 4069-4087

Author(s):

Sandra A. Nascimento ◽

Eupídio Scopel ◽

Camila A. Rezende

Keyword(s):

New Method ◽

Salt Crystallization ◽

Crystallization Pressure

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Some observations on rock weathering, Cumberland Peninsula, Baffin Island

Canadian Journal of Earth Sciences ◽

10.1139/e79-086 ◽

1979 ◽

Vol 16 (5) ◽

pp. 977-983 ◽

Cited By ~ 14

Author(s):

Stephen H. Waits

Keyword(s):

Salt Crystallization ◽

Rock Weathering ◽

Baffin Island ◽

Significant Modification ◽

Bedrock Weathering ◽

Arctic Conditions ◽

Selective Preservation ◽

Mechanical Weathering ◽

High Level

A variety of bedrock weathering features—both modern and remnant—including surface grus, polygonal cracks, siliceous glaze, tors, weathering pits, and tafoni typify upland outcrops on the Cumberland Peninsula. Tor ridges are particularly prevalent and at lower elevations they show significant modification and streamlining by flowing ice. On summit areas at elevations above 750 m, however, remnant corestones are preserved in situ, suggesting selective preservation of upland surfaces. Bedrock structure and composition, topographic position, and intensity of process strongly influence tor development. Weathering pits are common on high level, open summit surfaces where weathering occurs in response to both climate and continued removal of derived debris. Pit enlargement through lateral undercutting has been favoured by accumulation of protective bottom residua, mechanical weathering, and the presence of exfoliation crusts. It is postulated that salt crystallization plays a role in outcrop microweathering under present upland arctic conditions.

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New sustainable mortars for stone restoration in the context of climate change

10.5194/egusphere-egu21-9638 ◽

2021 ◽

Author(s):

Jose Diaz-Basteris

Keyword(s):

Physical Properties ◽

Moisture Absorption ◽

Raw Materials ◽

Point Of View ◽

Salt Crystallization ◽

Glass Waste ◽

Vapour Permeability ◽

James Bond ◽

S Waves ◽

Environmental Agents

Restoration mortars are a designated group of products made to repair damaged masonry. They must be compatible with the former support of stones and bricks, and protect original materials from environmental agents; aesthetical and historic aspects must not be neglected.&#160;To improve the ecological footprint of the restoration mortars while keeping their efficiency, we have tested several combinations of lime with aggregates and additives. Recycled and natural materials were used as additives such as pinecone resin, semi-milled cones of pine, milled glass waste, brick production residue.For research purposes different physical properties have been measured in prepared mortars: porosity, density, capillarity absorption, moisture absorption, water vapour permeability. We have also tested the mechanical properties and the P and S waves velocities (from which dynamic Young's modulus and Poisson&#8217;s ratio were inferred). The durability of mortars has been estimated by salt crystallization and frost/thaw cycles.The life cycle analysis (LCA) of such mortars allows us to understand the carbon footprint of each manufacturing process. Considering this we selected the raw materials, from an environmental and commercial point of view, to produce mortars fulfilling sustainability requirements. As a result, the developed mortars are compatible with aged stones, minimize environmental impact, and use minimum natural resources.&#160;Twenty mortar formulations with three different types of limes (NHL5, NHL3.5, CL90) and two different aggregates (siliceous and calcareous) have been studied using the LCA. Currently, five new formulations are being selected to be tested on Euville limestone. Adhesive strength (James Bond test), and physical properties will be measured on these mortars.&#160;

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