F. K. Kong MA, MSc, PhD, CEng, FICE, FIStructE, R. H. Evans CBE, DSc, D ès Sc, DTech, PhD, CEng, FICE, FIMechE, FIStructE (auth.)-Reinforced and Prestressed Concrete-Springer US (1987)

DoE mix design method 59
For a given slump and w/c ratio, the proportion of fine aggregate can
be determined from Fig. 2.7-3 [35) in which the grading zones are those
of Table 2.7-4. For example, suppose the specified slump is 10-30 mm,
the w/c ratio is 0.47, and the fine aggregate is in grading zone 3, then Fig.
2.7-3 gives the proportion of fine aggregate as between 32 and 38% by
weight, say 35%. Therefore, for this particular example,
fine aggregate content = 35% of total aggregate content
coarse aggregate content = (100-35)% of total aggregate content
Note that Fig. 2. 7-3 is for use where the nominal maximum size of the
coarse aggregate is 10 mm; the DoE document 35 contains similar design
charts for 20 and 40 mm maximum sizes.
Example 2.7-2
Using the DoE mix design procedure, design a mix if the target mean
strength is 43 N/mm 2 at 28 days and the required slump is 10-30 mm. The
following data are given:
SOLUTION
cement:
aggregate type
coarse:
fine: (see Table 2.7-4)
maximum w/c ratio:
maximum cement content:
Minimum cement content:
ordinary Portland
uncrushed, max. size 10 mm
uncrushed, grading zone 4
0.60 }
550 kg/m 3 see Table 2.5-7
300 kg/m 3
The solution will follow the steps listed above.
....
Ill
60
0 70
C7>
Ill
'-
C7> 60
C7>
0
~~~so
c+'
·- c
.... Ill
.... u
0._
c"'
....
OQ.
40
·-~ 30
'-
0
Q.
0
'-
a.
20
Slump: 0-IOmm
VB time: > 12s
v
/ I
,.
I/
r""' 2
~
,.. l/
-~
......
~
~ p.-
~
~ 1---~
......
- 4 .....
I0-30mm
12- 6s
,.,.... /""
/ I .....
y
~
e-t: f;;- ...,
_,.,....
3 ,.......
1-'1 t....-1-
-1-.-
7"
?
7
1---'
1---'
30-60mm
6-3s
/
c:_ -1-- '7'
,.,....
""" ~- - ;:;;;
~
~ ;;;;;;;-.....
~
p I;; p.-
;:..-
/
60-IBOmm
3-0s
..A'
~ ...... I
v
L...- ...... ~
...... ~ tl-f-----
:;;
4
;:;;;;-1-"" f----- ;;;;;;
1---'
t....- 1---' 4 t....-.-
70
60
so
40
t....- !-....... 80
10 0
0·2 o·4 0·6 0·8 0·4 o·6 o·8 0·4 0·6 o·8 0·4 o·6 o·8
water I cement ratio
Fig. 2.7-3 Proportions of fine aggregate for grading zones 1, 2, 3, 4 (see Table
2. 7 -4)---for use with 10 mm nominal maximum size coarse aggregate
(after DoE [35])
30
20
I