Croatian Union of Mechanical Engineers and Naval Architects
Abstract
Infracrvena termografija je metoda beskontaktnog mjerenja temperature i njezine raspodjele na površini promatranog objekta. Primjena termografije u zgradarstvu pruža velike mogućnosti kontrole kvalitete izvedbe kod novih građevina, ali i procjene trenutnog stanja starijih objekata. Osim što daje uvid u stanje objekta u smislu toplinske izolacije objekta, infracrvena termografija se može uspješno primijeniti za ocjenu stanja ovojnice građevine: otkrivanja različitih tipova grješaka (nedostataka i oštećenja) - otkrivanje mjesta odvajanja žbuke od podloge i mogućeg prisustva zraka ili vlage u slojevima ispod vanjske žbuke, te za procjenu stanja ravnih krovova - otkrivanje mjesta odvajanja sloja krovne ljepenke od podloge. Premda postoje različiti ograničavajući čimbenici kod termografskog snimanja građevinskih objekata, termografija se afirmirala kao metoda toplinske kontrole bez razaranja koja, u odnosu na neke druge metode nerazornog ispitivanja, posjeduje čitav niz prednosti. Između ostalog, metodom je omogućena trenutna analiza objekta na mjestu mjerenja kao i kontrola relativno velikih površina u kratkom vremenu, a naknadnom analizom moguća je i relativno jednostavna procjena kvalitete toplinske izolacije/toplinskih gubitaka objekta te otkrivanje strukture objekta ispod sloja žbuke. U radu su obrađeni primjeri detekcije različitih grešaka u području zgradarstva s osvrtom na zahtjeve norme HRN EN 13187. Obrađeni su slučajevi različitih stupnjeva oštećenja ovojnice zgrade, prisustvo vlage u zidovima objekta, toplinski mostovi i nekvalitetno brtvljenje, te prisustvo vlage i zraka u strukturi ravnog krova. U radu je posebno obrađeno mjerenje provedeno na upravnoj zgradi tvrtke Jadrolinija Rijeka, čiji je cilj bio utvrđivanje trenutnog stanja fasade i sukladno tomu davanje procjene o potrebi njezine sanacije. Za taj je slučaj, u sklopu analize termograma, provedena i numerička analiza prijenosa topline za karakteristične dijelove fasade sa i bez grešaka te su rezultati uspoređeni s rezultatima mjerenja.Infrared thermography is a method of contact-free temperature measurement providing temperature distribution on the surface of the observed building.
The use of thermography in civil engineering for building assessment purposes opens up large possibilities for control of construction quality when newly built edifices are concerned, but also when estimation of the current state of the old buildings is needed. Besides giving insight into the state of the building insulation quality, infrared thermography can be successfully applied in the evaluation of the building envelope: for detecting different defect types (flaws and damage) – for detecting locations where the plaster layer is detached from the wall base with possible presence of air or moisture in the layers beneath the outer plaster, as well as for estimation of the state of the plain roofs - detecting locations where the roof cardboard is detached from the base. Although there are different limitations when thermography inspection of buildings is concerned, infrared thermography is recognized as a thermal non-destructive testing method, which holds many advantages with respect to the other methods of non-destructive testing. Among others, the method enables instant analysis of the building at the location of the measurement, as well as the control of relatively large surfaces in a short period of time. In addition, post-analysis enables a relatively straight forward estimation of thermal insulation quality, of the building’s heat losses as well as estimation of the structure beneath the plaster layer of the building. This paper gives the examples of the detection of different defect types appearing in building structures along with an overview of the requirements of Croatian norm HRN EN 13187. Cases of different degrees of damage present in the building envelope are analyzed, as well as the presence of the moisture in building walls, the existence of thermal bridges and inadequate tightening, the presence of moisture and air in the structure of plain roofs. The measurements presented in this work were performed on the headquarter building of the company Jadrolinija Rijeka. The goal of this measurement was to determine the current state of the building facade and to give estimation of the extent of the facade recovery needed. For this purpose, together with the detailed thermogram analysis, the numerical analysis of the heat transfer through the characteristic facade parts with and without defects present in the structure was performed and numerical results were compared to the ones obtained by measurement
