Aktiivsöelisanditega betoonisegude radooni difusiooni mõõtmise uuring

Lõputöö raames tehtud uuringus on valmistatud erineva paksuse ja aktiivsöe kontsentratsiooniga katsekehad ning sooritatud eri metoodikaga katseid. Samuti on valmistatud samasuguste näitajatega survekatsekehad, et testida antud segu tugevust. Katsekehad on valmistatud mitmes etapis, jälgides ja arvestades juba olemasolevaid tulemusi. Katsetes on kasutatud omaloomingulist katseseadeldist, mis koosnes vastavalt katsete iseloomust kas ühest või kahest mõõtekambrist, erinevatest radoonigeneraatoritest, ringluspumbast Alpha Guard DF2000, mõõtevahendist Radon Eye Plus2 ja ühendusvoolikutest ning muudest väikedetailidest nagu ühendusvoolikud jms. Katsed on sooritatud kolme põhimeetodiga, mille erinevus seisnes radooni generaatoris. Tulemused on selekteeritud katsekehadest ja jagatud sarnasuse alusel gruppidesse. Tulemus eri paksusega katsekehade võrdluses ilma aktiivsöeta andis väga häid visuaalseid tulemusi, sest selgelt oli näha, et mida paksem katsekeha, seda vähem radooni läbis. Radooni läbivuse osas näitasid kolme erineva aktiivsöe sisaldusega maksimaalse paksusega katsekehad põhimõtteliselt sama tulemust ja materjalist endast täiesti piisas. Õhemate katsete juures on aga selgelt näha aktiivsöe toimimist. Ilma aktiivsöeta katsekeha puhul viide puudus ja radooni tase tõusis kohe väga kõrgele. Varasemalt erinevates katsetes uuritud aktiivsöe koguse 5% juures peaks selle mõju näha olema ja see tuleb ka antud uuringus selgelt välja. Kuigi tulemused 4% juures olid tunduvalt paremad ilma aktiivsöeta variandi kõrval, siis 5% juures olid need juba väga head ja 10% juures ideaalilähedased.

Hazardous substances are found all-around us, however, radioactive gases like Radon, that are invisible to the human eye, present a significant risk to human well-being. The hazards and risks posed by radioactivity have been known for over a century. The field of construction science and engineering is consistently researching methods and materials that can shield the human beings and our environment against these hazards and in-turn protect human health. While buildings can serve as an effective barrier between the inhabitants and the environmental hazards, they must be built with the right choice of materials to provide optimum protection, durability and environmental stability. One of the steps in that direction is to employ the use of reusable residual materials in place of non-recoverable virgin materials. This will result in improved sustainability and economy. In this context, activated Carbon is well-known for its effectiveness as a filter against various local pollutants. While, at present, many small-scale Radon barrier materials and technologies are currently used, none of them are large-scale. Although, initial research is promising but the topic of activated Carbon-based large-scale Radon protection in the construction industry requires further research. The present study tries to address this requirement so as to provide more research findings on this topic. In the present study, experiments are conducted on circular disc shaped samples of concrete produced with different thickness and different activated Carbon content. The Carbon used in the production of these samples was granulated. These samples were tested for Radon diffusion rates and their mechanical strength (stress). From these tests, it was found that the effect of activated Carbon is only observable in thinner discs (20 mm) as in thicker (40 mm) discs, the concrete mixture itself is able to attenuate Radon diffusion rate. In thinner discs, it was clearly observed that the presence of Carbon reduced the Radon diffusion rate where in discs without any carbon, the Radon levels rose sharply to much higher levels. 41 Moreover, according to previous research work, Radon diffusion rate attenuation is effectively attenuated at 5% of activated Carbon inclusion in concrete. In the present study, it was observed that 4% of activated Carbon inclusion was sufficient to significantly reduce the rate of Radon diffusion, whereas, at 5% it was better still and at 10% the attenuation was nearly ideal.