Concrete aggregate and cement mass content effects on compressive strength

Abstract

The mass content of aggregate (ma) and of cement (mc) of concrete comprise coefficient calculated as ma/mc. Some methods used for designing of concrete mixtures take into consideration this coefficient. In this paper, concrete mixtures were prepared so that mass of cement, water cement factor and granulometric composition have been varied. Values of the coefficient ma/mc in experimental research ranged between 7,20 in concrete mixtures mixed with 250 kg of cement to 3,60 in concrete mixtures mixed with 500 kg per 1m3. From the aspect of compressive strength of concrete, it has been established that optimum values of the coefficient ma/mc depend on the granulometric composition and water cement factor. At higher water cement factors, larger values of ma/mc coefficient are required to achieve the maximum strength under the given conditions.Pod masenim ucescem agregata (ma) i cementa (mc) u betonu podrazumeva se koeficijent koji se izracunava kao ma/mc. Neke metode koje se koriste za projektovanje sastava betonskih mesavina uzimaju u obzir ovaj koeficijent. U ovom radu betonske mesavine su spravljene tako da je varirana masa cementa, vodocementni faktor i granulometrijski sastav. Vrednosti koeficijenta ma/mc u eksperimentalnom istrazivanju kretale su se od 7,20 kod betonskih mesavina spravljanih sa 250 kg cementa do 3,60 kod betona koji su spravljani sa kolicinom cementa od 500 kg po 1m3. Posmatrano sa aspekta cvrstoce pri pritisku betona, utvrdjeno je da optimalne vrednosti koeficijenta ma/mc zavise od granulometrijskog sastava i vodocementnog faktora. Pri vecim vodocementnim faktorima potrebne su vece vrednosti koeficijenta ma/mc da bi se pod datim uslovima ostvarile maksimalne cvrstoce.