Environmental footprint study of mortar,render and plaster formulation / Studie über die Umweltauswirkungen von Mörtel

A comparative environmental assessment study focusing on the stages of mortar production and carbonation through hardening has been conducted by the European Lime Association in collaboration with mortar producers from various EU countries on 17 formulations of mortars, renders and plasters. The results of the “cradle‐to‐gate” for mortar and renders indicated that: There are no significant differences between products with low and high lime contents and depending on the lime content in the products, the contribution of the hydrated lime to the different environmental indicators can range between 0 % and about 20 %. However, there are clear differences in the environmental footprints of gypsum or lime based plasters. Based on the plaster composition investigated in this study, it appears that lime based plasters have the lowest environmental footprint for some of the impacts (primary energy consumption, abiotic depletion and water eutrophication), whereas for the remaining indicators the gypsum based plasters have the lowest environmental footprint. Depending on the lime content in the plasters, the contribution of the hydrated lime to the different environmental indicators can vary in a wide range, i. e. between 0 and 40 %. The differences in the environmental impacts of mortars, renders and plasters produced in integrated or non‐integrated mortar plants are generally rather small The lime carbonation process lowers the overall carbon footprint during the first period of the use phase of the mortars in buildings. This impact shall be taken into account in holistic LCA studies. If not, this leads to a wrong interpretation of the environmental impact of the mortars.     

Non‐destructive assessment of retaining wall of former coal mine plant

A large retaining wall (appr. 9 m high and 286 m long) of a former coal mine has been investigated using Ground Penetrating Radar (GPR), with two low frequency antennas (200 and 400 MHz), and Large Aperture UltraSound (LAUS) to gather information about the condition and inner structure of the wall. Three vertical lines were selected in representative areas of the wall to evaluate the usefulness of Non‐Destructive Testing (NDT) with these two methods. The LAUS results showed the layer structure at one line where the wall was enforced by a concrete shell and were unspecific regarding the inner structure beyond the first layer. GPR results were able to be collected much faster and showed some internal features. Penetration was limited to 2–3 m due to the high absorption in the material.     

Literature study on the rate and mechanism of carbonation of lime in mortars / Literaturstudie über Mechanismus und Grad der Karbonatisierung von Kalkhydrat im Mörtel

The hardening kinetics of a lime based mortar is based on the uptake of carbon dioxide from the ambient air. The presence of watervapour is required in order to enable the reaction between the CO₂ and the lime (calcium hydroxide). Via this reaction the hardening of air lime is net uptaker of CO₂. An extensive literature study was made on the fundamentals of the carbonation process in mortars with different compositions. The results of the study indicate that carbonation ranges from 80 % up to 90 %. It is clear that the mechanism and the kinetics of the carbonation depend strongly on the mineralogy, texture of mortars, type of additive used, the lime use for the mortar, the width of the walls, thickness of the mortar (less carbonation when mortar depth increases) as well as the timeframe allowing for the carbonation process to take place. Under natural conditions, actual building practice and depending on the thickness of the mortar/plaster, carbonation takes between a few weeks and several years. The results of this study were used for the environmental footprint study in order to calculate the capture of CO₂ that occurs progressively during the hardening of a building materials containing lime.     

Bond behaviour between textile reinforcement and mortar under tensile loading / Verbundverhalten zwischen textiler Bewehrung und Mörtel unter Zugbeanspruchung

Extensive experimental investigations are currently being carried out on various selected materials covering a wide range of properties to achieve a deeper knowledge about the bond performance of textile reinforced mortar (TRM) for masonry strengthening. The objective of the tests includes investigations of the bonding behaviour between alkali‐resistant glass textile reinforcement and mortar under tensile loading to determine the required anchorage and overlapping lengths of the reinforcement in the mortar‐based material. This article describes the test methods used as well as the results obtained so far. This research will also examine debonding of the mortar‐based reinforcement system and the masonry surface under shear load. The definition of these bond parameters is necessary for the design of textile‐reinforced masonry components, which will be developed in the near future. The research is also intended to contribute to the finding or even designing of matching alkali‐resistant glass textiles specifically for use in masonry.     

Analysis and refurbishment of damp cellar walls

In the following expertise report, the existing condition of the cellar of a semi‐detached house, which was built in a coupled construction, is analysed and considerations for a hygric refurbishment are discussed. First and foremost, it was necessary to find the cause of the damp present in the outside walls of the cellar of the building. In order to describe the current characteristics of the building, an inventory analysis was made of obvious building defects. This is summarised and described in the following report, which was the basis for all further proceeding. Building physics measurements and evaluations were carried out, building materials were examined for their physical properties and corresponding evaluations and analyses were carried out. Finally, all measurement results and findings were collected to provide a conclusive explanation for the existing defects to the building fabric of the building. This in turn was the foundation for all further measures to be taken in order to determine the necessary remediation concepts and changes to the interior design or the use of the rooms. The aim was to make the cellar space fully usable again and to be able to hand over a list of proposals for the necessary technical remediation measures to the client.