Vol.9, No 3, 2011 pp. 357 - 366
UDC 69.059.25:632.111.6=111
DOI: 10.2298/FUACE1103357Z
REHABILITATION OF BUILDINGS IN WINTER CONDITIONS
Slavko Zdravković, Dragoslav Stojić*, Dragana Turnić
University of Nis, The Faculty of Architecture and Civil Engineering, Serbia
E-mail: *dragoslav.stojic@gmail.com
Various factors are taken as the criteria for determining the susceptibility of materials to frost, such as: porosity and water absorption, volume changes, the number of freezing and thawing cycles. Mortars as a mixture of binder, water and sand, after placing and undergoing bonding and solidification processes, represent extremely porous materials, and the same holds for concrete. When the water turns into ice, it changes its volume measure unit from (Vω) into Vt = 1.09 Vω. If the concrete that has not completed bonding is exposed to frost, the process is likely to be suspended, and later when the warming starts, followed by the thawing of concrete, it will need the repeated vibrating in order to bind again and harden up without the detrimental effects on its strength. However, there are cases of devastating effects of frost on the hardened concrete. All the mentioned strategies should be kept in mind when performing remediation.
Key words: building, rehabilitation, frost, porosity, strength.
SANACIJA GRAĐEVINSKIH OBJEKATA U ZIMSKIM USLOVIMA
Kao kriterijumi za utvrđivanje osetljivosti materjala na dejstvo mraza, uzimaju se različiti faktori kao što su: poroznost i upijanje vode, zapreminske promene, broj mržnjenja i kravljenja. Malteri kao mešavina veziva, vode i peska, posle ugrađivanja, vezivanja i očvršćavanja predstavljaju izuzetno porozan materijal što se može reći i za beton. Kada voda pređe u led njena se zapremina menja od jedinice (Vw) i postaje Vt=1,09Vw. Ako beton koji još nije obavio vezivanje, bude izložen uticaju mraza, proces će verovatno biti obustavljen, a kada kasnije dođe do otopljavanja, pa i kravljenja betona, treba ga ponovo izvibrirati, pa će on vezati, i stvrdnuti se bez štetnih posledica po svoju čvrstoću. Međutim, dolazi i do razornog dejstva mraza i na otvrdnuti beton. Sve dalje rečeno treba imati u vidu prilikom izvođenja sanacije.
Ključne reči: objekat, sanacija, mraz, poroznost, čvrstoća