Assessment of the Climate Change Effects on Finnish Concrete Facades and Balconies

Although Finnish building stock is young, a significant share of Finland’s national property consists of buildings. A major part of that stock is now aged between 30 and 60 years and their outdoor facing structures are reaching or have already reached their ren- ovation date. The value of renovation has increased steadily since the 1990s and is now surpassing the value of new construction. Thus, maintenance and safeguarding the service life of the existing building stock is recognised as having a major effect on the national wealth. At the same time, the quality of, for example, the concrete facades and balconies built that time has found to be poor, mainly because majority of them were built during the time when quality requirements were not even at the level of need of the current climate. The goal of this research is to determine what needs to be done in the building stock to adapt to climate change. The research is limited to outdoor exposed concrete facades and balconies because of their significant role in the Finnish building stock, and because the current condition and deterioration mechanisms and their rates have been extensively studied before. However, the aim is that most of the findings can be utilised also in new construction, regardless of the construction material. This thesis discusses the effect of climate change by two ways: its effect on the intensity of selected climatic factors and their effect on the deterioration rate of the best-known deterioration mechanisms of concrete, i.e. corrosion of reinforcement and freeze-thaw damage. The results show that climate change is going to intensify especially wind- driven rain (WDR) load, which is a significant part of almost all of the most critical deterioration mechanisms. However, the effect is highly dependent on the location and the direction of orientation of the structure. The highest deterioration rates have been shown to be in coastal areas and southern areas and in structures facing southern directions. The geographical dependence is significant because a considerable share of Finnish existing building stock is located in the coastal area or southern Finland where the climatic load is and will be the most severe. On the other hand, the deterioration rate is and will be low in Lapland and so is the share of buildings. However, results imply that even with insufficient quality, the concrete structures can have a decent service life and the structures can be effectively protected against climatic factors, for example, by sheltering. The results of this study can be used to target both the actual methods used in renovation and preventative maintenance methods

Julkisivujen pitkäaikaisestävyyden rasitusolosuhteet

acceptedVersionPeer reviewe

Delayed ettringite formation (DEF) and its effect on freeze-thaw damage in Finnish concrete façades

The strongest drivers causing delayed ettringite formation (DEF) and its impact as a cause of freeze-thaw damage in Finnish concrete façades is still poorly known as it has been only briefly touched as a part of one dissertation [1] and one master's thesis [2]. The conclusion of both studies was that DEF might slightly accelerate freeze-thaw damage of concrete, but how strongly or how rapidly was not stated. To complement the knowledge on that matter, this article analyses Finnish façade structures built between 1960 and 2003 using large case-study databases, weather history data and statistical methods. As a result, it was found that DEF occurs in more than half of the Finnish concrete façades, but it significantly increases the freeze-thaw damage only when it has spread widely in the pore structure of concrete. Such case has been quite rare, since the amount of widespread DEF covers only 4.4% of all observations. Wind-driven rain (WDR) was found to be one of the most significant drivers for DEF, and if the façades are either completely protected from it or oriented in the direction which are least exposed to WDR, DEF was not observed extensively at all. Façades where no DEF was detected had WDR exposure an average of 1852 mm per year. The facades where DEF was found extensively had 68% more exposure, an average of 3127 mm per year.publishedVersionPeer reviewe

Methods for evaluating the technical performance of reclaimed bricks

Reusing deconstructed materials and components can help to decrease the environmental burden of buildings. To safely reuse reclaimed items in new construction, methods are needed to reliably identify the essential technical properties of the deconstructed products. This paper looks at salvaged bricks and examines different indirect test methods to assess their properties. The explored test methods include visual observation, pitch of a sound, ultrasonic pulse velocity (UPV), and thin section. Reclaimed clay bricks and calcium silicate bricks were used in the research. They originated from four different buildings and from different kinds of structures. New bricks of the same kinds were also tested for reference. The assessed properties entail initial rate of water absorption, water absorption capacity, compressive strength, and freeze-thaw durability. The results show that it is possible to assess the deviation of properties and sort out exceptional bricks from a series with visual observation and pitch of a sound. The deviation of different properties can also be assessed with the help of UPV. A correlation was found between UPV and water absorption, compressive strength and freeze-thaw durability. Lower UPV values mean higher water absorption capacity and vice versa. Compressive strength of bricks is clearly lower when the UPV value is low and higher when the UPV is high. Bricks with lower UPV values ( 3.0 km/s) were found to be non-durable. Between the mentioned two values, the freeze-thaw durability varied. Thin section was only used to assess freeze-thaw durability and it was found to be unreliable as a method.publishedVersionPeer reviewe

Betonielementtien uudelleenkäyttömahdollisuudet

Rakennusten purkaminen keskittyy Suomessa kasvukeskuksiin: sitä enemmän puretaan mitä enemmän rakennetaankin. Suurin osa 2000-luvulla purettujen betonirakennusten neliömetreistä on peräisin teollisuus- ja varastohalleista sekä liike- ja toimistorakennuksista. Asuinkerrostalojen purkaminen on toistaiseksi ollut vähäistä. On kuitenkin todennäköistä, että betonirakennusten purkaminen vain lisääntyy tulevaisuudessa. Betonirakentamisen volyymistä johtuen pienikin kasvu betonirakennusten purkamisessa lisää betonijätteen määrää ja prosenttiosuutta huomattavasti. EU:n jätedirektiivi vuodelta 2008, jonka mukaiseksi Suomen jätelakia muutettiin 2011, määrittelee, että kokonaisten tuotteiden valmistelu uudelleenkäyttöön on asetettava murskaavan materiaalikierrätyksen edelle. Vaikka useimpia elementtijärjestelmiä ei ole erityisesti suunniteltu elementtien ehjänä purkamista ja uudelleenkäyttöä silmälläpitäen, on erilaisissa koehankkeissa saatu siitä myös positiivisia kokemuksia. Suomen varsin nuoresta rakennuskannasta huolimatta siinä esiintyy huomattavasti korjaustarvetta. Tällaisten säälle alttiina olleiden rakenteiden uudelleenkäyttö on aina selvitettävä tapauskohtaisesti. Sellaisenaan niillä ei ole mahdollista saavuttaa nykyisin yleisesti vaadittavaa vähintään 50 vuoden käyttöikää. Sen sijaan rakennusten sisäolosuhteissa olevat rungot ovat yleensä moitteettomassa kunnossa. Rakennusten sisäilmaongelmat ovat jo pitkään olleet yksi merkittävä korjaustarvetta ja usein myös rakennusten purkamiseen johtava tekijä. Sisäilmaongelmat ovat hyvin tyypillisesti paikallisia ja ne syntyvät usean eri tekijän yhteisvaikutuksesta. Rakenneosien uudelleenkäytön kannalta huomionarvoista on, että sisäilmailmaongelmaisissakin rakennuksissa on yleensä lukuisia rakenneosia, joissa ei ole minkäänlaisia kosteus- tai mikrobivaurioita. Rakenneosien uudelleenkäyttöön vaikuttaa merkittävästi rakennuksen ja sen materiaalien ikä, rakennuksen käyttötarkoitus ja rasitus, jolle rakenteet ovat altistuneet sekä uusi käyttötarkoitus. Suurin uudelleenkäyttöpotentiaali on sellaisilla betonielementeillä, jotka voidaan irrottaa ja uudelleen asentaa helposti. Uudelleenkäyttöä suunniteltaessa pitää ottaa huomioon, että betonirakenteet, jotka on alun perin suunniteltu sisäympäristöön, eivät saa altistua uudessa käyttötarkoituksessa alkuperäistä ankarammalle rasitukselle. Runkorakenteiden merkittävin vaurioitumisriski on purkamisen ja kuljettamisen sekä muun käsittelyn aikana. Erityisesti aukollisten elementtien purkamisessa vaurioitumisriski on suuri. Betonielementtirakentamista ohjaavat normit ja ohjeet ovat muuttuneet useasti elementtirakentamisen alkuajoista lähtien. Kuormitukset ja rakenteiden kapasiteetit on tarkistettava aina tapauskohtaisesti ja tarvittaessa suunniteltava rakenteiden vahvistukset. Nykyiset lämmöneristysmääräykset edellyttävät myös lisälämmöneristystä vanhoihin ulkoseinäelementteihin. Pilari-palkkirunkoisen hallin hiilijalanjälkitarkastelut puoltavat hallin rungon uudelleenkäyttöä, sillä merkittävimmän hiilidioksidipäästöt syntyvät betonielementtien valmistamisesta. Elementtien kuljettamisen päästöt ovat vähäisiä verrattuna elementin valmistukseen, mutta ne on otettava huomioon hallin uudelleenkäytön hiilijalanjälkitarkasteluissa.<br/

Risk factors for moisture damage presence and severity in Finnish homes

Peer reviewe

Rakennusten kosteusvauriot ja ylilämpeneminen muuttuvassa ilmastossa – RAIL

Tutkimuksessa tehtiin laskennallisia tarkasteluja ulkoseinärakenteiden rakennusfysikaalisesta toimivuudesta nykyisessä ja projisoiduissa tulevaisuuden ilmastoskenaarioissa. Lisäksi laskennallisella mallinnuksella tarkasteltiin ilmastonmuutoksen vaikutuksia rakennusten ylilämpenemiseen ja lämpöviihtyvyyteen. Rakennusten kosteusvaurioiden ja niihin liittyvien mikrobien yhteyttä ihmisten terveyteen tarkasteltiin kahdella systemaattisella katsauksella. Korkeiden kesäajan lämpötilojen vaikutusta terveyteen nyt ja tulevaisuudessa arvioitiin epidemiologisin sekä vaikutusarvioinnin menetelmiin. Tehtyjen tarkastelujen perusteella suurin osa Suomessa yleisesti käytössä olevista ulkoseinä­rakenteista pärjää myös muuttuvassa ilmastossa. Homehtumisriski nousee sellaisissa ulkoseinärakenteissa, jotka päästävät viistosadetta lävitseen, pidättävät vettä rakenteen huokosverkostossa (tiili, läpäisevä betoni) ja tuuletus on heikkoa. Palvelutalojen sekä asuntojen laskennalliset ja havaitut lämpötilat nousevat korkeiksi jo nykyisessä ilmastossa. Pelkät auringonsuojausratkaisut eivät ole riittäviä pitämään huone­lämpötiloja riittävän alhaisella tasolla, vaan sen lisäksi tarvitaan myös aktiivista jäähdytystä erityisesti helleaaltojen aikana. Jäähdytys tulisi kohdistaa rakennuksiin, joissa asuu ikäihmisiä, sillä heillä terveysriskit ovat suurimmat. Ilman lisätoimia tulevat korkeiden lämpötilojen terveyshaitat huomattavasti lisääntymään Suomessa jo lähitulevaisuudessa väestön ikääntyessä.Tämä julkaisu on toteutettu osana valtioneuvoston selvitys- ja tutkimussuunnitelman toimeenpanoa. (tietokayttoon.fi) Julkaisun sisällöstä vastaavat tiedon tuottajat, eikä tekstisisältö välttämättä edusta valtioneuvoston näkemystä

Vocabulary acquisition with the help of video games : A quantitative analysis on the effects of gaming on vocabulary acquisition

The aim of this Master’s Thesis is to look at how video games affect vocabulary learning. As such, the thesis will first look at some of the theory on language learning, as well as theory on game-based learning (GBL). The theory will also cover flow and game genre discussions because both have been proven to have an effect on learning (Guan 2013, Jensen 2017), In addition, flow has been shown to occur more easily when playing video games (Cowley et al. 2008), therefore making it an important factor to understand when looking at the possible results of GBL. The present study looked at three different age groups, and their video gaming habits, which made it possible to analyse multiple different facets of possible facilitative effects of video games on the participants. The materials were gathered from 21 6th graders, 23 8th graders and from 20 second year upper secondary school students. The questionnaire they answered gave information on how much they played, how often they played and what types of games they played. The participants also took a shorter version of Paul Nation’s (2007) vocabulary size test, where they tested their knowledge some common and some more uncommon words. Since some participants did not play any video games this allowed the present study to compare gamers and non-gamers. The results showed that playing video games has a positive correlation with vocabulary size test scores, and that the genre of the game also has an effect. Future research should look at the co-occurrence of other hobbies with video gaming, to isolate the effects of game-based learning

Assessment of the Climate Change Effects on Finnish Concrete Facades and Balconies

Although Finnish building stock is young, a significant share of Finland’s national property consists of buildings. A major part of that stock is now aged between 30 and 60 years and their outdoor facing structures are reaching or have already reached their ren- ovation date. The value of renovation has increased steadily since the 1990s and is now surpassing the value of new construction. Thus, maintenance and safeguarding the service life of the existing building stock is recognised as having a major effect on the national wealth. At the same time, the quality of, for example, the concrete facades and balconies built that time has found to be poor, mainly because majority of them were built during the time when quality requirements were not even at the level of need of the current climate. The goal of this research is to determine what needs to be done in the building stock to adapt to climate change. The research is limited to outdoor exposed concrete facades and balconies because of their significant role in the Finnish building stock, and because the current condition and deterioration mechanisms and their rates have been extensively studied before. However, the aim is that most of the findings can be utilised also in new construction, regardless of the construction material. This thesis discusses the effect of climate change by two ways: its effect on the intensity of selected climatic factors and their effect on the deterioration rate of the best-known deterioration mechanisms of concrete, i.e. corrosion of reinforcement and freeze-thaw damage. The results show that climate change is going to intensify especially wind- driven rain (WDR) load, which is a significant part of almost all of the most critical deterioration mechanisms. However, the effect is highly dependent on the location and the direction of orientation of the structure. The highest deterioration rates have been shown to be in coastal areas and southern areas and in structures facing southern directions. The geographical dependence is significant because a considerable share of Finnish existing building stock is located in the coastal area or southern Finland where the climatic load is and will be the most severe. On the other hand, the deterioration rate is and will be low in Lapland and so is the share of buildings. However, results imply that even with insufficient quality, the concrete structures can have a decent service life and the structures can be effectively protected against climatic factors, for example, by sheltering. The results of this study can be used to target both the actual methods used in renovation and preventative maintenance methods

Long-term water absorption tests for frost insulation materials taking into account frost attack

Water absorption of several different frost insulation materials was tested for four years. The test took into account both immersion and frost attack to materials. On the basis of the research the water absorption on XPS specimens is significantly minor compared to EPS specimens that were studied. The most significant result was that freezing of test specimens did not affect on water absorption of XPS specimens but had a major effect on water absorption of EPS specimens. With frozen EPS specimen the absorption continued increasing even after 48 months of immersion. Presumably the reason for such a behaviour is that the pore structure of EPS is not able to resist the tension caused by freezing water and therefore cracks are formed. Thus, more water absorbs inside the EPS through the cracks and it causes cracking deeper in the specimen which is why absorption increases after every freezing period