Numera sker all industriell torkning av virke i sågverken i virkestorkar, som värms upp och därmed torkar virket till den optimala slutfuktkvot som tillönskas. Virkestorkar byggda i betong har länge varit ett stort problem för sågverksindustrin. Problematiken går tillbaka till 80-talet då man tvingades riva ett flertal torkar på grund av att betongtorkarna höll på att vittra sönder. Detta gällde för alla betongtorkar byggda fram till 70-talet. Det genomfördes i slutet på 90-talet en stor rapportundersökningen som behandlade de flesta typer av skador i betongtorkar. Fram tills idag har en närmare undersökning ej gjorts och det har fortfarande inte hittats standarder för reparation och underhåll som förlänger livslängden på betongtorkar. Sågverksindustrin förlorar varje år 10-tals miljoner kronor på reparationer och underhåll som i de flesta fall inte verkar fungera. Därför finns det en stor efterfrågan av tydliga instruktioner för val av material och hur dessa reparationer skall gå till. Rapporten behandlar den allmänna problematiken av skador som uppstår p.g.a. bland annat väldigt högt temperaturbelastade virkestorkar som är konstruerade i betong. Arbetet är uppdelat i två faser den ena fasen består av en teoridel som bland annat förklarar skadorna och dess uppkomst i betongtorkar. Den andra fasen behandlar en fältundersökning som genomfördes under rapportskrivningen samt de förslag till åtgärder som tagits fram. Denna rapport är en liten del av ett stort pågående projekt, där CBI Betonginstitutet och SP trä är projektutförare och samverkar med deltagande sågverk i Sverige och Norge samt leverantörer. Projektet ska mynna ut i en Guideline till sågverksindustrin, för att kunna utföra rätt reparationer med rätt materialval och därmed förlänga betongtorkarnas livslängd. Detta med utgångspunkt från fältundersökningens provtagningar. / Nowadays, all the process of industrial drying of lumber in sawmills are done in kilns, which the wood is heated and dried for the desired optimal moisture content. Timber drying kilns built in concrete has for a long time been a major issues for the sawmill industry. The problems goes as far back to the 80s when several wood kilns was forced to be demolished due to concrete kilns were about to crumble. This was mainly for all the concrete dries built up until the 70s. In the late 90's a report survey was carried out to investigate the damages that were inflicted in concrete dries. No other survey has been done since then and the report didn’t give tangible standards for repairs and maintenance that extends the service life in wood kilns. The sawmill industry loses each year tens of millions on repairs and maintenance that hasn’t shown any results of working. Therefore, there is a great demand of clear instructions for the selection of materials and how these repairs need to be done. The report deals with the general issues of very high temperature-loaded kilns constructed in concrete. The work is divided into two phases; one phase consists of a theoretical part including explaining of the damages and its emergence in the concrete kilns. The second phase deals with a field survey conducted during the report writing as well as the proposed measures have been developed. This report is one small part of a large ongoing project, where CBI and SP wood are the project implementers and interact with participating sawmills in Sweden and Norway and the suppliers. The project will culminate in a Guideline for the sawmill industry, to be able to perform the correct repair with proper materials and thereby extend the life of concrete kilns. This is based on field survey sampling. The project will culminate in a Guideline for the sawmill industry, to be able to perform the correct repair with proper materials and thereby extend the life of concrete drying. This is based on field survey sampling.

Purpose: this degree project will examine the possibilities of increasing the structural integrity in case of fire of a preexisting concrete building according to the rules in EKS 11, specifically for a hospital building. Furthermore, the degree project will provide solutions to increase the structural integrity in case of fire. Method: the study is based on a technical report provided by Kadesjös Ingenjörsbyrå AB where information about the hospital buildings technical aspects is presented. To examine current rules for fire-resistance rating of the hospital building, the regulations presented in BBR and EKS 11 were studied. Products had to fulfill the criteria of the European testing standards when they were evaluated as solutions that would increase the structural integrity of the building. The products were then evaluated according to the criteria presented in Eurocode 2 when dimensioning with tabulated data. An interview were held with Michael Försth professor in structural and fire engineering. Professor Försth were asked questions to evaluate potential methods and products that could increase the fire-resistance rating of the hospital building. Results: showed that proposed solutions are able to increase the structural integrity in case of fire of the hospital building to a degree where they were able to fulfill the requirements. Not all solutions were appliable on all building components of the hospital buildings. The difference in technical aspects of the solutions were presented. Conclusions: the identified solutions for increasing the structural integrity in case of fire are rock wool insulation, fire protection paint, additional concrete casting on columns and installation of sprinkler system. The solutions differ in technical aspects such as the space they take when implemented, weight increase when implemented, the amount they increase the structural integrity in case of fire when implemented and the method of implementing the solutions.