Recommendation of RILEM TC 271-ASC: New accelerated test procedure for the assessment of resistance of natural stone and fired-clay brick units against salt crystallization

This recommendation is devoted to testing the resistance of natural stone and fired-clay brick units against salt crystallization. The procedure was developed by the RILEM TC 271-ASC to evaluate the durability of porous building materials against salt crystallization through a laboratory method that allows for accelerated testing without compromising the reliability of the results. The new procedure is designed to replicate salt damage caused by crystallization near the surface of materials as a result of capillary transport and evaporation. A new approach is proposed that considers the presence of two stages in the salt crystallization test. In the first, the accumulation stage, salts gradually accumulate on or near the surface of the material due to evaporation. In the second, the propagation stage, damage initiates and develops due to changes in moisture content and relative humidity that trigger salt dissolution and crystallization cycles. To achieve this, two types of salt were tested, namely sodium chloride and sodium sulphate, with each salt tested separately. A methodology for assessing the salt-induced damage is proposed, which includes visual and photographical observations and measurement of material loss. The procedure has been preliminarily validated in round robin tests

Recommendation of RILEM TC 271-ASC: New accelerated test procedure for the assessment of resistance of natural stone and fired-clay brick units against salt crystallization

This recommendation is devoted to testing the resistance of natural stone and fired-clay brick units against salt crystallization. The procedure was developed by the RILEM TC 271-ASC to evaluate the durability of porous building materials against salt crystallization through a laboratory method that allows for accelerated testing without compromising the reliability of the results. The new procedure is designed to replicate salt damage caused by crystallization near the surface of materials as a result of capillary transport and evaporation. A new approach is proposed that considers the presence of two stages in the salt crystallization test. In the first, the accumulation stage, salts gradually accumulate on or near the surface of the material due to evaporation. In the second, the propagation stage, damage initiates and develops due to changes in moisture content and relative humidity that trigger salt dissolution and crystallization cycles. To achieve this, two types of salt were tested, namely sodium chloride and sodium sulphate, with each salt tested separately. A methodology for assessing the salt-induced damage is proposed, which includes visual and photographical observations and measurement of material loss. The procedure has been preliminarily validated in round robin tests

Influence of different types of solvent on the effectiveness of nanolime treatments on highly porous mortar substrates

Historic calcareous structures suffer from weathering processes that result in the loss of some of their original properties. Nanolime products represent an attractive choice for the consolidation of these substrates containing calcite due to their high chemical compatibility with the original structure. The effectiveness of nanolime products has been widely proven for superficial consolidation treatments (e.g. plasters and wall-paintings). However, its consolidation mechanism in highly porous substrates (e.g. limestones or lime mortars) still needs to be fully understood. The aim of this paper is to study the influence of different types of solvent on the effectiveness of nanolime treatments on highly porous lime-mortars. The consolidation effectiveness is investigated by evaluating changes on superficial cohesion, porosity, drilling resistance, water absorption by capillarity, drying rate and aesthetic properties. Results showed that nanolime dispersed in a mixture of isopropanol (50%) and water (50%) yielded slightly better consolidation properties in terms of reduction in porosity, increase in strength and penetration within coarse lime-mortars than nanolime dispersed in other solvents

ESTABLISHMENT OF STORE WITH TURKISH COTTON FABRIC

41 s. :obr., tab., grafy +CD ROMTato bakalářská práce se zabývá zřízením prodejny s tureckou bavlněnou metráží, přičemž jedna prodejna bude založena na Ukrajině a druhá prodejna v České republice, a jejich dalším porovnáním. Prodejny jsou porovnávány z pohledu podmínek pro dovoz bavlněné metráže z Turecka a analýzou finanční náročnosti a legislativy založení podnikání na území Ukrajiny a České republiky. Výsledkem práce je porovnání prodejen a rozhodnutí o vhodnějším státu jakožto lokalitě pro založení podnikání. Teoretická část práce seznamuje čtenáře se základními informacemi o pravidlech založení podnikání, daňových sazbách a normách dovozu bavlněné metráže z Turecka. Praktická část se zabývá analýzou situace na trhu a porovnáním prodejen. V další části je představen potenciální obchod a nabídka bavlněné metráže. V závěru se nachází posouzení zjištěných faktů a zhodnocení výsledků. Na základě výsledků byla zvolena nejvhodnější lokalita pro podnikání s tureckou bavlněnou metráží

Consolidation of weak lime mortars by means of saturated solution of calcium hydroxide or barium hydroxide

This paper presents research results on the effects of repeated treatments with saturated solutions of calcium hydroxide (lime water) or barium hydroxide (barium water) on consolidating a friable lime mortar. The influence of lime or barium water treatment on various mainly mechanical characteristics of consolidated lime mortar was studied in detail by means of tests on non-standard specimens fabricated from a poor mortar of 1:9 vol. lime-to-sand ratio. The traditional lime water technology and barium hydroxide treatment were further compared with distilled water and lime water with added metakaolin. Lime water treatment of a specific lime mortar was shown to be effective after a sufficiently large number of applications (160 saturations) into a weak lime mortar. No consolidating effect of distilled water on the compressive strength of the tested mortar with a low lime content (1:9) was observed. The mechanical characteristics of the tested mortar were not improved by treatment with lime water with added metakaolin. Barium water treatment significantly increased mainly the tensile strength of the tested lime mortar

Consolidation of renders and plasters

The paper addresses the consolidation o

ТЕОРЕТИЧЕСКИЙ И ПРАКТИЧЕСКИЙ АСПЕКТЫ ПРОФИЛАКТИКИ КОНФЛИКТОВ У ПОДРОСТКОВ С ОГРАНИЧЕННЫМИ ВОЗМОЖНОСТЯМИ ЗДОРОВЬЯ СРЕДСТВАМИ ДЕЛОВОЙ ИГРЫ

The article presents the results of psychological-pedagogical experiment on conflict prevention teenagers with disabilities by means the business game. The aim of the study was to develop a theoretically grounded and experimentally verify the pedagogical conditions of conflict prevention teenagers with disabilities by means of the business game.The novelty of the research lies in the specification of the concept of "conflict prevention", the theoretical justification of pedagogical conditions of conflict prevention teenagers with disabilities by means of the business game. Developed and tested pedagogical conditions of the prevention of conflicts contributed to the emergence of statistically significant differences in the level of conflict in the experimental group and the control on the ascertaining stages of the experiment.В статье представлены результаты психолого-педагогического эксперимента по профилактике конфликтов у подростков с ограниченными возможностями здоровья средствами деловой игры. Целью исследования было разработать, теоретически обосновать и экспериментально проверить педагогические условия профилактики конфликтов у подростков с ограниченными возможностями здоровья средствами деловой игры. Новизна исследования заключается в конкретизации понятия «профилактика конфликтов», теоретическом обосновании педагогических условий профилактики конфликтов у подростков с ограниченными возможностями здоровья средствами деловой игры. Разработанные и апробированныепедагогические условия профилактики конфликтов способствовали появлению статистически значимых различий по уровням конфликтности в экспериментальной группе на констатирующем и контрольном этапах эксперимента