DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

CEL 774 CONSTRUCTION PRACTISESCONSTRUCTION PRACTISES

Mix design of Concrete: British (DOE) method

B. Bhattacharjee

CIVIL ENGINEERING DEPARTMENTIIT DELHI

General Outline

• The DOE method • Mix design with Fly ash

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

DOE METHOD

f m =f ck + 1.65σStep 1 : selection of w/c from curvesStep 2: Estimate water content based on

slump/Ve-be time, m.s.a and shape of aggregate

Step 3: Calculate cement content Step 4: Wet density of concrete & total aggregate content

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

DOE METHOD

Step 5 : Determination of FA based on m.s.a and w/c and grading zone of sand from curves

–Apparently most logical way of choosing w/c–Takes shape of aggregate in to account–A mix design procedure with FA is also available

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

DOE METHOD

w/c determination

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

Crushed 40

Uncrushed 47

OPC or

SRC

28 days compressive strength

Equation for w/c curves

1-21

w/c21

and

; law) s(Abraham' Strength

where

BKAKB

Af

KKf

cw

==

==

×=

[ ]47.60ln11.58 5.01 −×= fK

⎥⎦

⎤⎢⎣

⎡ −84.6371

176.540

=20.5f

K

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

DOE METHODwater content determination

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

m.s.a Type Slump 0-10

S 10-30 mm

S 60-180 mm

U-Crshd 135 160 195

Crshd 170 190 225

U-Crshd 115 140 175

Crshd 155 175 205

40 mm

20 mm

Step 4: Calculate cement content

w/cw/c*= Min (w/c*= Min (w/ccurvecurve, w/c, w/cdurabilitydurability) ) ..

C=Max(W/ w/c*, Cdurability).

DOE METHOD

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

In case of CA & FA are different W=2/3Wf+1/3Wc

DOE METHODStep 4: Wet density (Dwet) of concrete

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

Step 4: Calculate total Aggregate content

Total aggregate content (Total aggregate content (WWaggagg)= Wet )= Wet densitydensity--CC--W W ..

DOE METHOD

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

Step 5 : Determination of FA based on m.s.a and w/c and grading zone of sand from curves

DOE METHOD

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

Step 5 : Determination of FA

% passing through 600 Micron sieve1 – 152 – 403 – 604 – 805 – 100

DOE METHOD

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

Step 5 : Determination of FA

% passing through 600 Micron sieve1 – 152 – 403 – 604 – 805 – 100

DOE METHOD

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

% passing through 600 Micron sieve1 – 152 – 403 – 604 – 805 – 100

Step 5 : Determination of FA

Step 5: Calculate Fine Aggregate content

Fine aggregate content Fine aggregate content FFaggagg = = ppww×× ((WWaggagg) ) kg/mkg/m33..

DOE METHOD

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

pw is determined from graphs

Cagg= Wagg-Fagg

When fly ash (PFA) is used in the mix control mix proportions are calculated as usual

Total percentage of PFA (pTotal percentage of PFA (pff) is fixed as ) is fixed as specified/desiredspecified/desired..

DOE METHOD

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

Water content is reduced depending on pf

W'= W-ΔW

DOE METHODwater content reduction

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

FA in Cement (%)

Slump 0-10

S 10-30 mm

S 60-180 mm

10 5 5 10

20 10 10 15

40 20 20 25

DOE METHODCement and FA contents

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

– p=F/(C'+F)×100; F=pC'/(100-p)

C'=[100-p]W' /[(100-0.7p)(W/C)*]k=0.3

For durability max W/(C+F) with max p =25% or as per IS 1489 Part I

W/C*=W'/ (C' +kF)

DOE METHODWet density is assumed same as control mix

B. Bhattacharjee

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

Fine aggregate content is calculated as before

Total aggregate content= Dwet - C‘-W'-F

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

SummaryDOE method

Mix design with PFA

DEPARTMENT OF CIVIL ENGINEERING, IIT DELHI

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