INCREASING THE BONDING STRENGTH OF THE PLASTERING COATING TO THE BASE

The strength of plaster coatings depends on the quality of adhesion of the applied plaster layer with the base. The bases for applying plaster coatings are necessarily prepared, the technology of preparing the bases may differ depending on the coating applied. It is established that the closer the initial structures are in structure, the higher the quality of the plaster coating as a whole. According to geonics, the relationship of structures in building composites is based on basic properties, general physical and mechanical indicators, which equally apply to both the building plaster solution and the base. At the same time, a contact binder is allowed between the base and the plaster layer with similar indicators, the presence of which guarantees reliable adhesion and strength of the resulting coating. The use of plaster solutions on enriched fine substandard sands with complex modified additives makes it possible to improve the technological qualities of the mortar mixture, the physical and mechanical characteristics of plaster solutions and optimize the technology of applying the plaster coating. Successive application of plaster layers on technogenic sands with different size modulus allows creating a base rough coating on the base, which closes the main defects and creates the base for the next layer of plaster solution. The Chechen Republic has extensive reserves of very fine and fine local sands, which in their basic properties are inferior to medium- and coarse-grained sands, but with a rational selection of composition, enrichment of grain composition can be used to produce high-quality construction composites. To enrich the grain composition of fine local sands, it is proposed to use dropouts of concrete scrap crushing, the volumes of which are significant on the territory of the Chechen Republic. Dropout of concrete scrap crushing by chemical composition is suitable for enriching local fine sands and when selecting the composition of the plaster solution increases the physical, mechanical and technological properties of the mortar mixture.

Revealing unique inscriptions of a Nazi collaborator in Doodencel 601 of the Oranjehotel

During the Second World War the German occupants of the Netherlands made ample use of the Scheveningen prison near The Hague, popularly nicknamed the Oranjehotel. One former death cell in this infamous prison (Doodencel 601) has been preserved in its original condition, showing wartime inscriptions on the cell walls. Interestingly, a small section of the wall has been given an additional plaster layer, presumably covering inscriptions. Here, we report on the visualization of this enigmatic text, which so far had escaped the reach of historians. Our visualization methodology was threefold. First, we determined the cell-wall stratigraphy and its composition based on a sample cross-section. Second, we prepared a physical model wall, mimicking the layering of the original cell wall. Third, we tested a combination of raking light photography and infrared thermography on the model wall. Applying this methodology on the original wall revealed the inscriptions, including the author’s name Daniël de Blocq van Scheltinga, a prominent Nazi collaborator, as well as a calendar and an important date of his post-war trial in the fall of 1945. Our visualizations flawlessly dovetail with archival findings. Together, they offer an intimate view of an early post-war inmate of the Scheveningen prison, whose message was covered up once the cell was transformed into a war monument in 1946.

Integrating Non-Destructive Testing, Laser Scanning, and Numerical Modeling for Damage Assessment: The Room of the Elements

For preservation efforts and stability assessment of historic structures it is imperative to understand the extent of existing damages and possible modes for how they could have occurred. The aim of this work is to illustrate the importance of integrating documentation, non-destructive testing, and numerical modeling for damage assessment of heritage structures. In particular, this work explores the synthesis of these techniques on a plastered masonry wall in Palazzo Vecchio. Laser scanning was used to capture the geometry of the wall while terrestrial photogrammetry and high-resolution images were used to document the magnitude of cracking in the plaster layer. High resolution thermal images were used to document the distribution of stones and additional cracks not visible through the plaster layer. The results of documentation and non-destructive testing were used to generate an as-built model for structural analysis. Finite distinct element modeling was used to simulate the response of the wall to a series of loading conditions. By comparing the results of simulation to existing crack patterns, theories for how the damage occurred were generated.

Defects of sandwich walls

Thermal protection of spaces contributes to the fact that sandwich walls dominate in heated buildings. Their design requires knowledge regarding the operating principles of sandwich systems. Without knowledge of these principles, numerous mistakes are made. The study describes mistakes encountered made during erection of triple-layer and double-layer walls. The effects of a shortage and excess of connecting pieces in triple-layer walls are presented. For double-layer walls, the necessity of insulation expansion joints is shown using an example. Using the tests, it is proven that the strength of the adhesive layer created during the autumn/winter transitional period is very heavily decreased, even more than 50%, which in connection with over-stiffened anchors leads to very numerous cracks, to the destruction of the external layer of insulation. High diffusion resistance of the external layer of insulation with low diffusion resistance (mineral wool) also leads to the destruction of the adhesive & plaster layer. Furthermore, the considerable significance of the use of good quality reinforcing, anchoring, gluing and painting & plastering materials was emphasized.

Grip Fixing Instead of Adhesive - Exterior Insulation Finishing Systems (EIFS) as a Sorted Recyclable Façade System with Reclosable Fastener Fixation

The paper describes the project facade4zeroWaste which includes the development, architectural design relevance, grants of patents, results of pre-certification testing’s and the product publication in the time frame from 2009 till 2017. Aim of the research project facade4zeroWaste was the idea of a recyclable facade insulation system that can easily be dismantled after its lifetime and reused thanks to an innovative grip fixing system consisting of mushroom-shaped heads and loops - Grip fixing instead of adhesive. The project won numerous prices and awards like the EQAR - Recycling Prize 2015 or the Innovation Award for Architecture and Building 2017. The project is a contract research project tasked by Sto SE & Co. KGaA, Germany and Sto GesmbH, Austria. The façade system was presented to the public in January 2017 as the product Sto Systain R (R = render: seamless plaster layer surface) on the building fair BAU 2017 in Munich. *

Botanical Materials from the Burials of Ust-Smolka Cemetery nearby Izborsk

В статье характеризуются ботанические материалы из трех погребений могильника Усть-Смолка. Были выделены карбонизированные материалы: угли и семена, а также отмыты зафиксированные глинистой обмазкой пласт цветков, семян, фрагментов веточек травянистых и древесных растений, лист дерева. Анализ ботанических материалов трех погребений показал значительные различия по видовому составу древесных и травянистых растений. Культивируемые виды выявлены только в пробах погребения № 12 - пшеница компактная (Triticum compactum), ячмень обыкновенный (Hordeum vulgare) и ячмень бутылковидный (Hordeum lagunculiforme). The article describes the botanical materials from 3 burials of Ust-Smolka cemetery. During the work botanical materials from burials of Ust-Smolka were studied. The allocated carbonized materials: charcoal and seeds were singled out and fixed by a clay plaster layer flowers, seeds, fragments of twigs of herbaceous and woody plants, tree leaves were washed. The analysis of three burials botanical materials showed significant differences in species composition of plants: woody and herbaceous. Cultivated species were found only in samples of burial № 12 - Wheat (Triticum compactum) and Barley (Hordeum vulgare & Hordeum lagunculiforme).

Influences of Environmental Conditions on the Cracking Tendency of Dry-Mixed Plastering Mortar

Cracking tendency is one of the important performances of dry-mixed plastering mortar (DMPM). Environmental condition is a key factor to affect the cracking tendency of DMPM. For the purpose of evaluating the cracking resistance of DMPM and revealing the influence of environmental conditions on the cracking tendency of DMPM, a series of experiments were performed on restriction-induced cracking behaviors as well as free shrinkage, water loss, and mechanical properties of DMPM. The restricted shrinkage tests were based on ring tests and plate experiments. The results showed that the initial drying age exhibits significant influence on the cracking tendency of DMPM, and there was a stress balance period when the initial drying age was 2 days. But, the phenomena cannot be observed when the initial age was 3 d, 5 d, and 7 d. In order to eliminate the cracking tendency of DMPM, it should avoid water loss from the plaster layer during construction in practical engineering, especially, before initial drying ages.

Studies on the materials and manufacturing technology of the murals unearthed at Shimao Site in Shenmu County, Shaanxi

This paper presents preliminary scientific analytical results and discussion on the murals unearthed at the Shimao Site in Shenmu County, Shaanxi Province. The murals were composed of pigment layer, plaster base layer and daub layer. The pigments used include hematite, goethite, glauconite and carbon black. Same with the floor plaster layer of the house foundations in the site, the plaster layer of murals is made of calcium carbonate. For the painting procedure, a draft had firstly been designed by engraved lines, and then the murals were painted with various pigments. A tentative comparative study shows that the manufacturing technology and painting techniques of the Shimao mural are similar to that of the murals of the Han and Tang Dynasties. It indicates that the fundamental manufacturing technology of mural had probably been established in the Erlitou Period at latest, which was just followed and enriched over the Han and Tang Dynasties.

Humidity Conditions of Enclosing Structure with Silicate Brick Veneer and Variable Air Gap

The main function of walling system is to protect from environmental impact and to create favorable climate indoors. At the present time people use such tape of structures, such as: wall with silicate brick veneer, curtain wall system with a thin plaster layer and curtain wall system with air gap as well as without it. The results of the thermomoist calculation of enclosing structures with silicate brick veneer without air gap is presented in article. Technical guidelines for normalization of humidity conditions for data structures are provided in article. The main purpose is to calculate and to develop design consideration for realization enclosing structures with silicate brick veneer without air gap. The results of the calculation show conformity of the walling system to the required energy efficiency, hygiene and comfort standards.