Betoonis kasutatavate hüdrofobiseerivate lisaainete toime

Käesoleva lõputöö koostamisel võeti hüdrofobiseerivate lisandite toimeefekti tuvastamisel aluseks lisandite tootelehtel lubatud mõjud. Mujal maailmas läbiviidud katsed ei anna tõe¬pärast infot lisandite positiivsetest või negatiivsetest mõjudest koos Eestis kasutatavate kohalike täitematerjalide ja Kunda portland-komposiittsemendiga toodetud betoonidega. Katseplaan valmis koostöös AS Ruduse ning katses kasutavate lisandite Penetroni, Xypex-i ja Betocrete-i Eesti esindajatega. Autor on töös kirjeldanud katsemetoodikaid lisandite veepidavuse ja „iseparanemise” kontrollimiseks. Katsemetoodikad jagunevad standardiseeritud katseteks, mis sisaldasid vee sissetungimissügavuse määramist ning standardiseerimata meetoditel läbiviidud katseteks. Põhjalikumalt on käsitletud standardiseerimata katseid, mis hõlmavad endas katsekehade ja pragude moodustamist. Tulemustes on tehtud kokkuvõtted lisandite mõjust betooni omadustele. Omaduste juures on välja toodud lisandite mõju betooni plastsusele, õhusisaldusele ja survetugevusele. Lisandite toimetest on välja toodud veepidavuse suurenemist ning kuni 0,4 mm laiuste pragude sulgumist. Veepidavuse all on mõeldud betooni veepidavamaks muutmist lisandite kasutamisega. Töös selgitati betooni iseparanemise võimet lisandiga ja ilma lisandita.

The effects of hydrophobic additives stated in product sheets were used as the basis of detecting the effects of the respective additives. Tests performed in other countries do not provide accurate information on the positive or negative effects of additives combined with local filling materials and concretes produced in Kunda from Portland-composite cements that are used in Estonia. The experimental plan was prepared in cooperation with AS Rudus and the Estonian representatives of Penetron, Xypex, and Betocrete – additives used in the experiment. In the thesis, the author has described testing methods for checking the water-tightness and 'self-improvement' of the additives. The testing methods are divided into standardised tests, which included the determination of the penetration depth of water, and non-standardised methods for conducting tests. Non-standardised tests, which involve the formation of test pieces and cracks, are covered in detail. The effects of the additives on the properties of concrete have been summarised in the results. With regard to the properties, the effect of the additives on the plasticity, air concentration, and compressive strength on concrete have been specified. With regard to the effects of the additives, increases in water-tightness and closure of cracks that are up to 0.4 mm in width have been indicated as well. Water-tightness is defined as an increase in the water-tightness of concrete by the use of the additives. In the thesis, the ability of concrete to self-improve with the help of an additive and without additives was tested.