Curved Glass – Quality and Application

The desire of modern architecture for free form structures opens a large market forcurved glass. Compared to flat glass, the production of curved glass is much moredifficult because of additional parameters through the bending process. Since thereis no standard available for curved glass in construction so far, at present the rulesfor flat glass are being considered. However, several cases of damage show that theapplication of curved glass needs own regulations to avoid glass breakage on theconstruction site. Therefore, the Munich University of Applied Sciences and theRWTH Aachen University have performed a research program [1] concerning thequality control and criteria of curved glass

The effect of optical anisotropies on building glass façades and its measurement methods

Commonly, in the evaluation of the optical appearance of glass panes in building envelopes, anisotropies are a reason for a dispute between the architect or client and the façade manufacturer. Sometimes each party has a different perception, how strong the anisotropies are and what is permissible. This paper discusses in the first part the formation of the anisotropies and their natural sources. It is shown that the appearance of this phenomenon is dependent on the environmental conditions of the building site as well as the glass quality. If the application of thermally tempered glass cannot be avoided, the quality assurance of the production process has to be carefully planned. Furthermore a method for the quantitative measurement of anisotropies is proposed and prescribed in detail. This method can assist in the quality assurance process. Measurements are showing that probably the best tempered glass offers slight anisotropies and that under unfavorable conditions these anisotropies can become evident

The effect of optical anisotropies on building glass façades and its measurement methods

Commonly, in the evaluation of the optical appearance of glass panes in building envelopes, anisotropies are a reason for a dispute between the architect or client and the façade manufacturer. Sometimes each party has a different perception, how strong the anisotropies are and what is permissible. This paper discusses in the first part the formation of the anisotropies and their natural sources. It is shown that the appearance of this phenomenon is dependent on the environmental conditions of the building site as well as the glass quality. If the application of thermally tempered glass cannot be avoided, the quality assurance of the production process has to be carefully planned. Furthermore a method for the quantitative measurement of anisotropies is proposed and prescribed in detail. This method can assist in the quality assurance process. Measurements are showing that probably the best tempered glass offers slight anisotropies and that under unfavorable conditions these anisotropies can become evident

Interlaboratory comparison for quantitative chlorine analysis in cement pastes with laser induced breakdown spectroscopy

International audienceConcrete structures experience severe damage during service, such as pitting corrosion of rebars caused by the ingress of chlorine (Cl) into the porous concrete structure. The ingress can be monitored using laser-induced breakdown spectroscopy (LIBS), a promising civil engineering technique used to detect Cl in concrete structures in addition to conventional wet chemistry methods. The key advantages of LIBS are high spatial resolution, which is important when analyzing heterogeneous concrete samples, as well as the almost complete absence of sample preparation. To assess LIBS as a reliable analytical method, its accuracy and robustness must be carefully tested. This paper presents the results of an interlaboratory comparison on the analysis of Cl in cement paste samples conducted by 12 laboratories in 10 countries. Two sets of samples were prepared with Cl content ranging from 0.06-1.95 wt.% in the training set and 0.23-1.51 wt.% in the test set, with additional variations in the type of cement and Cl source (salt type). The overall result shows that LIBS is suitable for the quantification of the studied samples: the average relative error was generally below 15 %. The results demonstrate the true status quo of the LIBS method for this type of analysis, given that the laboratories were not instructed on how to perform the analysis or how to process the data