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(a) (b)

Figure 3: Sieve analysis of (a) recycled coarse aggregates and (b) natural coarse aggregates.

3. MIx PRoPoRtIoNs

In total 14 mixes grouped into three parts were used in this study. In the first part, shown in Table 3, four mixes are used. The first mix
was the control containing 100% NCA and 100% OPC, while the second mix contained 50% RCA as partial replacement of NCA and
100% OPC. The third and fourth mixes were very similar to the second mix except 50% slag and 50% fly ash, respectively were used
as partial replacement of OPC. In the second part, shown in Table 4, the effects of different SF contents on third and fourth mixes of
the first part were evaluated. In third part, shown in Table 5, four mixes were used where the first and second mixes were the control
concrete and concrete containing 50% RCA as partial replacement of NCA, respectively. In the third and fourth mixes the effects of
2% NS and 10% UFFA, respectively on second mix were investigated. Detail mix proportions of all mixes are shown in Tables 3-5.

table 3: part one: Mix proportion of recycled aggregate concretes containing slag and fly ash

MIx DEsIgnAtIon MIx ProPortIons In kg/m 3 slUMP
oPc fly Ash slAg ncA rcA nfA wAtEr sUPErPlAs- (mm)
tIcIzEr
Control 450 - - 1100 - 770 180 - 95
50 RCA 450 - - 550 550 770 180 - 80

50 RCA+50 Slag 225 - 225 550 550 770 180 - 105
50 RCA+50 Fly ash 225 225 - 550 550 770 180 - 100

table 4: part two: Mix proportion of recycled aggregate concretes containing slag, fly ash and silica fume
MIx DEsIgnAtIon MIx ProPortIons In kg/m 3 slUMP
oPc fly Ash slAg sIlIcA ncA rcA nfA wAtEr sUPErPlAs- (mm)
fUME (sf) tIcIzEr

50 RCA+50 Slag+5 SF 225 - 202.5 22.5 550 550 700 180 1.82 90
50 RCA+50 Slag+10 SF 225 - 180 45 550 550 700 180 2.58 90
50 RCA+50 Slag+15 SF 225 - 158.5 67.5 550 550 700 180 2.8 100
50 RCA+50 Fly ash+5 SF 225 202.5 - 22.5 550 550 700 180 1.50 90

50 RCA+50 Fly ash +10 SF 225 180 - 45 550 550 700 180 2.10 90
50 RCA+50 Fly ash +15 SF 225 158.5 - 67.5 550 550 700 180 2.43 80

58 The IndIan ConCreTe Journal | SepTember 2019