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Mazoria – Durame – Durgi – Omo River Road Project
Lot 1:-Mazoria – Durgi [km 0+000 – km 71+200] Road Project
Contract 2: Hadero - Durgi [km 37+500 - km 71+200]
Mix Design for Cement Concrete Class --- (C-15/20)
Trial No. LC - 3
(Cement Type: Derba PPC)
1) Summary of Requirements
Cement Content : Minimum = 250 kg/m3 [Project & ERA's Technical Specification]
: Maximum = 550kg/m3 [Project & ERA's Technical Specification]
Maximum Water/Cement Ratio :- 0.5 [Project & ERA's Technical Specification]
Required Slump :- 40-50 mm [From Table A 1.5.3.1, ACI 211.1 - 91 & as amended by
the Project Technical Specification Sub-clause 8405(h) ]
2) Determination of Target Mean Strength
Required/Characterstic Cylinderical Compressive Strength (f 'c) :- 15 Mpa
(A) ~ Target Average Compressive Strength (f cr) When Suffiicient Historical Data's are not available [From Table 4.2, ACI 214R-02]:-
'
~ Target Average Compressive Strength [Table 4.2 below]: 21.90 Mpa
(B) ~ Target Average Compressive Strength (f 'cr) When Suffiicient Historical Data's are available [From Table 4.1,Table 4.3,Eq.4-2b and ACI 214R-02]
~ Standard Deviation of the Test Record for this Concrete Class[S,ACI 214R-02] : 3.58 Mpa
Modification Factor For the Calculated Standard Deviation [Table 4.1 below] : 1
Probability of Meeting the Specified Strength Z,Values of Z for Various Percentages of Tests Falling Between the mean +ZS
and the mean –ZS [Table 4.3 below] :
~Number of Tests in Each Average [n]:- 3
~ Target Average Compressive Strength [f'cr=f'c+ZS/√n]:- 15 Mpa
3) Constituent Material Sources
2.1 Cement : Portland Pozzolan Cement (PPC) Produced and Supplied by Derba Cement
2.2 Coarse Aggregate : Crushed Aggregate Produced at km 49+700 a Nominal Size of 20mm
2.3 Fine Aggregate: Blended Sand (50% - crushed sand from 54+600, 50% - natural sand from Areka)
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2.4 Water : From a Source Located at Km 43+800 (Sana River)
4) Input Data's
CA
Parameters Water Cement Sand/FA
"02" "01"
Sp. Gravity 1 2.98 2.59 2.57
Absorbition (%) … … 2.40 2.24
Natural Moisture Content (%) … … 1.21 0.89
Fineness Modulus … … 3 … …
Dry Rodded Unit Weight (Kg/m 3) … … … 1655
Loose Unit Weight (Kg/m 3) … … 1580 1517 1497
5)Water-Cement Ratio
Nom.max size of aggregate= 20 mm
Target Avg Compr. Strength= 22 Mpa
~w/c= 0.66 For a nom. Max size of aggr.of 20mm…[Table A1.5.3.4 (a) and (b) of ACI 211.1 - 91]
if (w/c >= 0.5), take water-cement ratio to
0.66 [as amended by the Project Technical Specification Sub-clause 8400 ]
be =
6) Amount of Mixing Water and Cement Content Estimation
~Cement content (to be economical we consider fixing the quantity of cement)
= 275 Kg per cu.m of concrete
Water-Cement Ratio= 0.66
Amount of mixing water= 182 Kg per cu.m of concrete
Therefore, take the amount of cement to be= 275 Kg
Therefore, take the amount of mixing water to be= 182 Kg
7) Estimation of Coarse Aggregate Content
Nom.max size of aggregate= 20 mm
Fineness Modulus of Sand/Fine Aggregate= 3
~Volume of CA, on a dry rodded basis,= 0.6 cu.m…[Table A1.5.3.6 of ACI 211.1 - 91]
Therefore, the volume of CA per unit volume of Concrete is= 0.386 cu.m………. 992.02 Kg (dry)
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8) Estimation of Fine Aggregate Content
>>>Absolute Volume Method
Vc= 0.092 cu.m
Vw= 0.182 cu.m
Vca= 0.386 cu.m
Vair= 0.02 cu.m…air from [Table A1.5.3.3 of ACI 211.1 - 91]
~Vs= 0.32 cu.m
Therefore, the sand/fine aggregate content per unit volume
0.32 cu.m…………. 828.80 Kg (Dry)
of concrete is=
9) Adjustment of Constituent Materials for Natural Moisture
Estimated Qty.
Adjusted Qty. (Kg per cu.m of
Constituent Materials (Kg per cu.m of Absorption (%) NMC (%) Free Water (%) Free Water (kg)
concrete)
concrete)
Cement (PPC) 275 275
Water 182 205
Coarse Aggregate (dry) 992.02 2.24 0.89 -1.35 -13.39 1000.9 (wet)
Fine Aggregate (dry) 828.80 2.4 1.21 -1.19 -9.86 838.8 (wet)
Therefore the mass of each component to get 1cu.m of concrete is :
Cement= 275 Kg
Water= 205 Kg
Coarse Aggregate(wet)= 1001 Kg
Sand (wet)= 839 Kg
Total= 2319 kg/m3
10) Composition of Laboratory Trial Batch, scale the masses down to produce 0.027m3 of concrete
Therefore the mass of each component to get 0.027 m3 of concrete is :
Cement= 7425 gm
Water= 5528 gm
Coarse Aggregate(wet)= 27023 gm
Sand (wet)= 22648 gm
Total= 62624 gm 2319 kg/m3
The batch as mixed shows the follwing properties :
Measured Slump= 43 mm
Workability = O.K.
Additional Water= 150 gm
Water (Net Mixing)= 5044 gm
Unit Weight of Fresh Concrete= 2432 kg/m3
Yield of Trial Batch= 0.03 m3
New (w/c) Ratio= 0.66 < 0.5 [Project & ERA's Technical Specification]
11) Corrected Proportions of Constituent Materials for 1m3 of Concrete
>>> The volume of ingredients other than air in the original trial batch was :
Vc= 0.002 m3
Vw= 0.006 m3
Vca= 0.011 m3
Vs= 0.009 m3
Total= 0.028 m3
Since the Yield was= 0.026 m3
Amount of air which was detectable within the precision of
the unit mass test and significant figures of the 0.002 m3
calculations=
>>>The determination of adjusted 1cu.m batch quantities can be completed as follows :
Vc= 0.099 m3
Cement= 294.00 Kg Vw= 0.194 m3
Water= 194.00 Kg Allowances for Vc= 0.000 m3
Coarse Aggregate(wet)= 1039.00 Kg Vca= 0.401 m3 (dry basis)
Vair= 0.002 m3
>>>Total volume exclusive of Fine Aggregates = 0.304 m3
787.36 Kg (Dry)
>>> Sand/fine aggregate content per 1 Cu.m of concrete is
0.304 m3………….
=
796.89 Kg (Wet)
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Therefore, the mass of each component to get 1cu.m of concrete is : 0.027 m3
Cement= 294 Kg 7938 294 300
Water= 194 Kg 5238 +200 0.194 0.20
Coarse Aggregate(wet)= 1039 Kg 28053 0.693 0.70
Sand (wet)= 797 Kg 21516 0.569 0.60
Total= 2324 kg/m3
12) Laboratory Test Results of the Trial Batch
Compr.
Max.load at Average
Cast Date Age in days Slump (mm) Weight (g) Density (kg/m3) Strength
Failure (KN) (Cylindrical)
Cube (Mpa.)
7 0 0.00
7 0 0.00 0.0
7 0 0.00
13
44
20
28 0 0.00
2/
28 0 0.00 0.0
/1
16
28 0 0.00
Target Average Compressive Strength (f'cr) =21.9Mpa
13) Measuring Box Design
Measuring Box sizes, for volume batching in manufacturing of concert on-site, is designed accordingly as follows.
Table below provides calculation of the volume of aggregate for one bag ( 50kg ) of cement.
Conversion Size of Measuring Box
Quantity *loose Volume
Constituent Materials quantity (kg/Per Loose density (kg/m 3)
(kg/m3) (m3)
Bag) Length (m) Width (m) Height (m)
Cement (PPC) 294 50 - - - - -
Water 194 33 - - - - -
Coarse agg.(67%),19mm 696 118 1517.0 0.078 0.50 0.40 0.39
Coarse agg.(33%),9.5mm 343 58 1497.0 0.039 0.50 0.40 0.19
Fine aggregate 797 136 1580.0 0.086 0.50 0.40 0.43
Total 2324 * Loose volume of aggregate =Quantity per 50kg cement / loose unit wight
☻Box sizes (50cm Length * 40cm Width * X cm Height) & Recommended Volume of Water Per Bag of Cement will be :-
Volume of Water Per Bag of Cement = 33 Liters
Coarse Agg. Per Bag of Cement,19mm= Two box each 2*(19.5 cm height)
Coarse Agg. Per Bag of Cement,9.5mm= One box each 1*(19 cm height)
Fine agg.(Sand) Per Bag of Cement= Two box each 2*(21.5 cm height)
Remark:-
Contractor's Lab. Technician Consultant's Lab. Technician
Contractor's Material Engineer Consultant's Material Engineer (PME)
