Vol.8, No 1, 2010 pp. 23 - 34
UDC
666.942.3/.7:691.32:620.175/.176(045)=111
DOI: 10.2298/FUACE1001023K
A STUDY ON THE INFLUENCE OF CURING ON THE STRENGTH OF A STANDARD GRADE CONCRETE MIX
M.V. Krishna Rao1, P. Rathish Kumar2*, Azhar M. Khan3
1Dept. of Civil Engg., CBIT, Hyderabad-500075, A.P, India
2Dept. of Civil Engg., NIT Warangal-506004, A.P, India
*E-mail:
drrateesh@gmail.com
Curing is essential if concrete is to perform the intended function over the
design life of the structure while excessive curing time may lead to the escalation of the
construction cost of the project and unnecessary delays. Where there is a scarcity of water
and on sloping surfaces where curing with water is difficult and in cases where large
areas like pavements have to be cured, the use of curing compound may be resorted to.
The parameters of the study include the curing period [1, 3, 7, 14 and 28 day], curing
method [conventional wet curing, membrane forming compound curing and accelerated
curing] and the type of cement [Ordinary Portland Cement(OPC) 43 grade, Portland
Pozzolana Cement(PPC) 43 grade and Ordinary Portland Cement(OPC) 43 grade +10%
Silica Fume(SF) replacement for cement]. In all a total of 99 cube specimens were cast
and cured under different conditions before testing. Test results indicate a drop in
strength at all ages for concretes with PPC and the one in which 10% OPC is replaced by
silica Fume(SF) in comparison with the concrete with OPC. Curing by membrane forming
curing compound yielded nearly the same results as that of conventional wet curing for
concrete with OPC and there was a marginal decrement in concrete with PPC. Predicted
28-day strength of concrete from the accelerated curing test was found to be on a
conservative side compared to control concrete.
Key words:
Compressive Strength, Curing, Silica Fume, Non-Destructive Testing,Ordinary Portland Cement (OPC)
STUDIJA UTICAJA NEGE NA ČVRSTOĆU STANDARDNOG KVALITETA BETONA
Nega je neophodna kako bi beton obavljao svoju funkciju za projekovani vek konstrukcije, dok
prekomerna nega može dovesti do povećanih troškova projekta i nepotrebnog zadržavanja. Tamo gde
je nestašica vode kao i na nagnutim površinama gde se nega betona vodom obavlja teško i u
slučajevima gde se nalaze velike površine, poput pločnika koje treba negovati, može se pribeći
korišćenju jedinjenja za negu betona formiranjem membrane. Parametari studije obuhvataju periode
nege od 1, 3, 7, 14 i 28 dana, metode nege (konvencijalna nega kva[enjem vodom, nega jedinjenjem
koje formira membranu i ubrzani tretman) i vrste cementa (Običan Portland cement (OPC) 43 klase,
Portland cement Pucolan (PPC) 43 i običan Portland cement (OPC) 43 klase+10% silikatne prašine
(SF) kao zamene za cement. Ukupno 99 uzoraka kocke su izliveni i negovani pod različitim uslovima.
Rezultati testa ukazuju na pad čvrstoće u svakom starosnom dobu betona sa PPC i u onoj kojoj je
10% OPC zamenjeno silikatnom prašinom (SF) u odnosu na beton sa OPC. Nega sa membreno
folijom dala je skoro iste rezultate kao kod konvencionalne mokre nege za beton sa OPC i došlo je do
marginalnih smanjenja u betonu sa PPC. Predviđene 28-dnevne čvrstoće betona testa ubrzane nege
su bile konzervativne u poređenju sa kontrolnim betonom.
Ključne reči:
Čvrstoća na pritisak, nega, silikatna prašina, ispitivanje bez razlaganja, običanPortland cement (OPC)
