Understanding Deterioration due to Salt and Ice Crystallization in Scandinavian Massive Brick Masonry

Abstract

Extensive durability problems such as weathering and degradation are found in historic Scandinavian brick masonry buildings, especially from the neo-Gothic period. These are largely due to the crystallization of salts and frost action in the bricks and mortars. This article aims to show and illustrate which salts and crystals are found in historic brick masonry buildings and to describe their appearance and behavior. An additional aim is to explore possibilities of preventing salt-related damage on internal masonry wall surfaces, such as using hemp-lime sacrificial plaster beneath the plaster. The objective is to show the mechanisms behind salt-related problems and to perform a case study and a laboratory study on salt-damaged brick masonry containing sodium sulphate. In order to prevent and stop damage to the masonry, it is important to be able to identify the nature of the salt damage and the type of salt that caused the damage. Neo-Gothic brick masonry buildings require well-planned, continuous maintenance of the masonry. It is therefore of the utmost importance to have an understanding of the complex functions of the masonry and of the salts that can cause damage to these historic buildings.

Assessing the effect of a white Portland cement admixture on the early frost-thaw resistance of NHL-based masonry mortar

“…Moreover, the mortars were used to build test walls near the historic ruin of Thaur in Tyrol to estimate their usability in a real application, a common technique that is often used by restorers (described e.g. in [23]). An overview of the conducted methods that are strongly interrelated and support each other's significance is given in Fig.…”

Analytical Investigation of Deterioration Aspects in the Mihrab of Madrasa Gawhariyya of Al-Azhar Mosque, Egypt

“…During salt crystal growth, high stress can arise even in large pores. The crystallization stress is higher in materials with small pores [11]. This weathering process, besides providing a loss of aesthetical effects, due to the surface alteration of the blocks, shows a more fundamental threat to the stability of the structure.…”

The Effect of Climate Change on Weathering: Evidences from Heritage Buildings under Subtropical Conditions

“…Deterioration at the base of an adobe wall (left) and characteristic fissure on the upper part of an adobe wall caused by the action of rainwater (right) (Illampas et al, 2009). Each separate render layer spalled off was caused by freezing temperatures in a lean lime render saturated with water (Balksten et al, 2021) The main mechanisms that outline weathering and lead to building material deterioration due to weathering are the following:  Wet and dry expansion  Frost induced weathering  Salt crystallisation  Biological degradation  Chemical Weathering  Mechanical Weathering  Thermal Expansion Deterioration All deterioration mechanisms are directly or indirectly water based. Upon absorbing water, building materials become saturated (Figure 2).…”

“…2. Deterioration at the base of an adobe wall (left) and characteristic fissure on the upper part of an adobe wall caused by the action of rainwater (right) (Illampas et al, 2009).Each separate render layer spalled off was caused by freezing temperatures in a lean lime render saturated with water (Balksten et al, 2021).…”