RESEARCH OF HUMIDITY MIGRATION PROCESSES IN WALLS MADE FROM NEW GENERATION AUTOCLAVED AERATED CONCRETE. (English)

JAUNĀS PAAUDZES GĀZBETONA SIENU ŽUŠANAS PROCESA PĒTĪJUMI. (Latvian)

Acquired results of humidity migration processes in walls made from new generation autoclaved aerated concrete. Two experimental walls, on the northern and southern part of the building, were built in Tallinn Technical school by imitating real living space in between. For construction of the walls was used autoclaved aerated concrete blocks EcoTerm 375 mm in thickness, volume weight E 400 kg/m³, glued together with a 2 mm thick layer of glue mortar. Starting from year 2005 there was carrying out various thermal measurements on regular basis. It is find out that monitoring of humidity migration processes in autoclaved aerated concrete walls accurately could be done by cut out test pieces and put them on the scales. Humidity measurements with measuring device ALMEMO - 2290-8 and sensors FHA 646-1 give inaccurate results, especially then humidity of wall exceed 10%. Recommendable that air permeability of finishing is equal with that on autoclaved aerated concrete, because in other hand after internal and external finishing works were done the drying process in autoclaved aerated concrete wall could become slower. It is clarify that thermal inertia influence not only thermal qualities of autoclaved aerated concrete wall, but also drying process of wall. A long term research carried out by the Tampere Technical University in Finland showed that for multilayer constructions the air permeability is comparatively larger in comparison to homogeneous solid autoclaved aerated concrete wall constructions. During the experiment, by determining the air permeability in the room, a pressure difference of 50 Pa was created inside the room in comparison to the pressure in the surrounding environment. The airtightness was measured by the measuring device Infiltec Blower Door. The determined air permeability for homogeneous external walls constructed from the Eco Term blocks 375 mm in thickness does not exceed 1 m³/(m²·h), that correspond to the construction norms of the Republic of Latvia LBN 002-01. Condensation in walls made from the Eco Term blocks could arise in point there is point of intersetion of saturated vaquour and non saturated vaquour curves, but no in the point there temperature reach 0°C. In the walls construction constructed from autoclaved aerated concrete blocks glued together without heat insulation this vaquour curves do not cross each other and this means that there is no condensation processes. In this experiment we get great amount of measurements, that could extend information about thermal qualities of autoclaved aerated concrete walls construction built on Baltic region climatic conditions. [ABSTRACT FROM AUTHOR]

Iegūti eksperimentāli rezultāti par jaunās paaudzes gāzbetona sienu žūšanas procesa norisi. Eksperiments tiek veikts Tallinas Tehniskajā skolā, kur ir uzbūvēta eksperimentāla māja ar ailām ziemeļu un dienvidu fāsadēs no EcoTerm blokiem ar biezumu 375 mm, tilpummasu ≤400 kg/m³, izveidojot šuves ar līmjavu. Sākot ar 2005. gadu tiek veikti regulāri mērījumi lai noteiktu sienu siltumtehniskās īpašības. Konstatēts, ka gāzbetona sienu mitruma monitoringu precīzi var veikt izgriežot paraugus un sverot tos. Savukārt mitruma tarēšanas līknes, izmantojot devējus FH 646 - 1, nedod precīzus rezultātus, it sevišķi, ja sienas mitrums ir virs 10%. Izveidojot sienas ārējo un iekšējo apdari gāzbetona sienu žūšanas process palēninās, tāpēc ieteicams ārējo apdari izveidot ar materiāliem, kuriem ūdens tvaiku caurlaidības koeficenta vērtība ir tuva ar gāzbetona ūdens tvaiku caurlaidību. Ir noskaidrots, ka gāzbetona sienas siltuma inerce ietekmē ne tikai siltumtehniskos rādītājus, bet arī žūšanas procesus. Somijas zinātnieki Tamperes Tehniskajā Universitātē ir konstatējuši, ka daudzslāņu ārsienu konstrukciju gaiscaurlaidība ir ievērojami lielāka nekā gāzbetona ārsienu konstrukcijai. Eksperimenta laikā nosakot sienas gaisa caurlaidību telpas iekšpusē tika radīta spiediena starpība 50 Pa salīdzinot ar apkārtējo vidi. Retinājuma lielums tika mērīts ar aparātu Infiltec Blower Door. Mērījumi parādīja, ka ārsienai no Eco Term 375 mm blokiem gaiscaurlaidība ir mazāka par 1 (m³/m²h) un atbilst Latvijas būvnormatīva LBN 002-01 prasībām. Kondensāts sienā, kura veidota noEcoTerm blokiem 375 mm biezumā, var rasties nevis tur, kur ir temperatūras nullpunkts, bet gan tur, kur krustojas piesātināta un nepiesātināta tvaika līknes. Viendabīgā gāzbetona bloku ārsiena, bez papildu siltinājuma, šīs liknes nekrustojas, tāpēc šādā konstrukcijā kondensāts neveidojas. Eksperimenta gaitā ir iegūta apjomīga rezultātu datu bāze, kura sniedz pilnīgāku priekšstatu par gāzbetona norobežojošo konstrukciju siltumtehniskajiem rādītājiem ekspluatācijas apstākļiem, kuri raksturīgi Baltijas republiku reǵionam. [ABSTRACT FROM AUTHOR]

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