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.     

Performance labels for assessing the sustainability of buildings – from offices to detached and semi‐detached houses / Gütesiegel für die Nachhaltigkeitsbewertung von Gebäuden – Vom Bürobau bis zu Ein‐ bis Zweifamilienwohnhäusern

For some time now, certain types of buildings in Germany have been required to undergo a sustainability assessment. Increasingly, that now also includes residential buildings. A research project is currently underway to develop and test suitable criteria for the assessment of small residential buildings, the preliminary results of which were showcased at the BAU 2015 trade fair in Munich. With the help of examples, this article presents the criteria and provides some information on their application.