Design specification
M25 M15
Condition Project Spec. General spec. Proposal
Water contents 185 kg/m3 185 kg/m3 185 kg/m3
Cement ratio min 270 kg/m3 330 kg/m3 330 kg/m3 270 kg/m3
W/C 65 % 55 % 55 %
Air contents 4.5 % 4.5 % 4.5 %
Chlorine contents 0.3 kg/m3 0.3 kg/m3 0.3 kg/m3
Slump 15,18 12,18 6,8 6,8
Conc. strength 36,27 N/mm2 25 N/mm2 25 15
Salinity in sand 0.04 % 0.04 % 0.04 %
M25 M15
Required data OP-1 OP-2 OP-3 OP-4 OP-5
1 Specific gravity of Coarse aggregate (20+10) 2.85 2.85 2.85 2.85 2.85
assumed
2 Specific gravity of Fine aggregate 2.68 2.68 2.68 2.68 2.68
3 Specific gravity of Cement 3.15 3.15 3.15 3.15 3.15
4 Bulk density of Coarse aggregate (20+10) 1460 1460 1460 1,460 1,460
assumed
5 Bulk density of Fine aggregate 1386 1386 1386 1,386 1,386
6 Water requirment 185 kg/m3 185 kg/m3 185 kg/m3 178 kg/m3 160 kg/m3
7 Cement requirement 400 kg/m3 375 kg/m3 350 kg/m3 325 kg/m3 325 kg/m3
8 W/C ratio 0.463 % 0.493 % 0.529 % 0.548 % 0.492 %
9 Plastisizer 2% 2% 2% none Fail on slump
OP-1
For decreasing of W/C ratio
the adjustment of sand by absolute volume and total aggregate
0.6 - 0.463 = 0.1375
for 1% decreasing of W/C ratio
= -1 x 0.1375 x 20
= -2.75
% of Fine aggregate contents
= 35 -2.75
= 32.25
% of Coarse aggregate contents
= 100 - 32.25
= 67.75
400 1 1 1 1
0.98 = 185 + + x x x
3.15 Fa 2.68 0.3225 1000
Fa = 577.4
= 577 kg/m3
400 1 1 1 1
0.98 = 185 + + x x x
3.15 Ca 2.85 0.6775 1000
Ca = 1289.9
= 1,290 kg/m3
Water Cement Fine aggregate Coarse aggregate
185 kg/m3 400 kg/m3 577 kg/m3 1290 kg/m3
0.46 1 1.4425 3.225
23.1 Litter 50 kg 72.13 kg 161.3 kg
1bag
Plasticizer
Sikament 170S 0.3 % of cement contents 120 ml
CONVERSION OF DESIGN MIX PROPORTION BY WEIGHT INTO CUBIC FEET(ft3)
Fine Coarse Aggregate
Material Properties Cement Aggregat
e 3/4(20mm)G-1(40mm)
Fineness Modulus -
Absorption 1.670 0.150
Loose Unit Weight( dry) 1,386 1,458
Rooded Unit Weight (dry) 3.15 1,609 1,673
Bulk SpecificGravity (SDD) 2.680 2.850
Abrasion Loose (%)
Soundness (%) 5.81 4.62
DESIGN MIX PROPORTION OF M25@28DAYS BY WEIGHT
Actual Weight(kg) per Cube Meter(m3)
Materials Absorption Total Dry SSD Correct
Moisture condition condition Weight
a. Cement 400 400
b. Fine Aggregate 1.670 577 587 577
c. Coarse Aggregate
20mm 0.150 1290 1,292 1290
d. Water 185 185
Batch weight may vary depending on the total actual moisture of materials
1. Reduce the design ino 1 bag of cement;
50 / 400 = 0.13
Using materials under SSD condition;
Fine Aggregates (S-1);
577 x 0.13 = 72
Coarse Aggregate (3/4);
1,290 x 0.13 = 161
Water;
185 x 0.13 = 23.1
Therefore the reduce weight of the materials are;
Cement ; 50 kg
Fine Aggregates (S-1) ; 72 kg
Coarse Aggregate (3/4) ; 161 kg
Water; ; 23.125 liters
Note; Quantity of water will vary depending on the Actual Total Moisture (ATM) of the materials
he materials
2 Convert the reduce weight of Fine & coarse aggregate into cubic meter (m 3);
In conversion of reduce weight into cubic meter (m 3) used the Saturated Surface Dry (SSD)
Specific Gravity (Sp.Gr.) of the material.
kilogram (kg.) to Cubic meter (m3)
Weight of material
Sp.Gr. of the materialx1000
Fine Aggregate (S-1)
72 kg m3
= = 0.027
2.68 x (1000)
Coarse Aggregate (3/4)
161 kg m3
= = 0.057
2.85 x (1000)
3 From the converted value of kilogram (kg.)to cubic meter (m 3),convert it into cubic foot (ft3)
Fine Aggregate (S-1) 0.03m3x(3.28ft/1m)3=1.1ft
0.027 m3 x (3.28ft/1m)3 = 0.950 ft3
Coarse Aggregate (3/4)
0.057 m3 x (3.28ft/1m)3 = 1.997 ft3
4 Water adjustment
Determine first the Actual total Moisture of the Material
The SSD weight of the materials are;
Fine Aggregate (S-1) 72 kg
Coarse Aggregate (3/4) 161 kg
Water 23.13 liters
Computation for water adjustment;
(1+Actual Total Moisture/100)
=(SSD Weight of materials) x
(1+Absorption/100)
Note; Use absorption value from the preliminary quality test result of aggregates
OP-2
For decreasing of W/C ratio
the adjustment of sand by absolute volume and total aggregate
0.6 - 0.4933 = 0.1067
for 1% decreasing of W/C ratio
= -1 x 0.1067 x 20
= -2.13
% of Fine aggregate contents
= 35 -2.133333
= 32.8667
% of Coarse aggregate contents
= 100 - 32.867
= 67.1333
375 1 1 1 1
0.98 = 185 + + x x x
3.15 Fa 2.68 0.3287 1000
Fa = 595.4
= 595 kg/m3
375 1 1 1 1
0.98 = 185 + + x x x
3.15 Ca 2.85 0.6713 1000
Ca = 1293.3
= 1,293 kg/m3
Water Cement Fine aggregate Coarse aggregate
185 kg/m3 375 kg/m3 595 kg/m3 1293 kg/m3
0.49 1 1.5867 3.448
24.7 Litter 50 kg 79.33 kg 172.4 kg
1bag
Plasticizer
Sikament 170S 0.2 % of cement contents 75 ml
OP-3
For decreasing of W/C ratio
the adjustment of sand by absolute volume and total aggregate
0.6 - 0.52857 = 0.0714
for 1% decreasing of W/C ratio
= -1 x 0.0714 x 20
= -1.43
% of Fine aggregate contents
= 35 -1.428571
= 33.5714
% of Coarse aggregate contents
= 100 - 33.571
= 66.4286
350 1 1 1 1
0.98 = 185 + + x x x
3.15 Fa 2.68 0.3357 1000
Fa = 615.305
= 615 kg/m3
350 1 1 1 1
0.98 = 185 + + x x x
3.15 Ca 2.85 0.6643 1000
Ca = 1294.7
= 1,295 kg/m3
Water Cement Fine aggregate Coarse aggregate
185 kg/m3 350 kg/m3 615 kg/m3 1295 kg/m3
0.53 1 1.7571 3.7
26.4 Litter 50 kg 87.86 kg 185.0 kg
1bag
Plasticizer
Sikament 170S 0.2 % of cement contents 70 ml
OP-4
For decreasing of W/C ratio
the adjustment of sand by absolute volume and total aggregate
0.6 - 0.547692 = 0.0523
for 1% decreasing of W/C ratio
= -1 x 0.0523 x 20
= -1.05
% of Fine aggregate contents
= 35 -1.046154
= 33.9538
% of Coarse aggregate contents
= 100 - 33.954
= 66.0462
325 1 1 1 1
0.98 = 178 + + x x x
3.15 Fa 2.68 0.3395 1000
Fa = 635.9053
= 636 kg/m3
325 1 1 1 1
0.98 = 178 + + x x x
3.15 Ca 2.85 0.6605 1000
Ca = 1315.4
= 1,315 kg/m3
Water Cement Fine aggregate Coarse aggregate
178 kg/m3 325 kg/m3 636 kg/m3 1315 kg/m3
0.55 1 1.9569 4.04615
27.4 Litter 50 kg 97.85 kg 202.3 kg
1bag
CONVERSION OF DESIGN MIX PROPORTION BY WEIGHT INTO CUBIC FEET(ft3)
Fine Coarse Aggregate
Material Properties Cement Aggregat
e 3/4(20mm)
Fineness Modulus -
Absorption 1.670 0.150
Loose Unit Weight( dry) 1,386 1,458
Rooded Unit Weight (dry) 3.15 1,609 1,673
Bulk SpecificGravity (SDD) 2.680 2.850
Abrasion Loose (%)
Soundness (%) 5.81 4.62
DESIGN MIX PROPORTION OF M15 @28DAYS BY WEIGHT
Actual Weight(kg) per Cube Meter(m3)
Materials Absorption Total Dry SSD Correct
Moisture condition condition Weight
a. Cement 325 325
b. Fine Aggregate 1.670 636 647 636
c. Coarse Aggregate
20mm 0.150 1,315 1,317 1315
d. Water 178 178
Batch weight may vary depending on the total actual moisture of materials
1. Reduce the design ino 1 bag of cement;
50 / 325 = 0.15
Using materials under SSD condition;
Fine Aggregates (S-1);
636 x 0.15 = 98
Coarse Aggregate (3/4);
1,315 x 0.15 = 202
Water;
178 x 0.15 = 27.4
Therefore the reduce weight of the materials are;
Cement ; 50 kg
Fine Aggregates (S-1) ; 98 kg
Coarse Aggregate (3/4) ; 202 kg
Water; ; 27.385 liters
Note; Quantity of water will vary depending on the Actual Total Moisture (ATM) of the materials
he materials
2 Convert the reduce weight of Fine & coarse aggregate into cubic meter (m 3);
In conversion of reduce weight into cubic meter (m 3) used the Saturated Surface Dry (SSD)
Specific Gravity (Sp.Gr.) of the material.
kilogram (kg.) to Cubic meter (m3)
Weight of material
Sp.Gr. of the materialx1000
Fine Aggregate (S-1)
98 kg m3
= = 0.037
2.68 x (1000)
Coarse Aggregate (3/4)
202 kg m3
= = 0.071
2.85 x (1000)
3 From the converted value of kilogram (kg.)to cubic meter (m 3),convert it into cubic foot (ft3)
Fine Aggregate (S-1) 0.03m3x(3.28ft/1m)3=1.1ft
0.037 m3 x (3.28ft/1m)3 = 1.288 ft3
Coarse Aggregate (3/4)
0.071 m3 x (3.28ft/1m)3 = 2.505 ft3
4 Water adjustment
Determine first the Actual total Moisture of the Material
The SSD weight of the materials are;
Fine Aggregate (S-1) 98 kg
Coarse Aggregate (3/4) 202 kg
Water 27.38 liters
Computation for water adjustment;
(1+Actual Total Moisture/100)
=(SSD Weight of materials) x
(1+Absorption/100)
Note; Use absorption value from the preliminary quality test result of aggregates
QUALITY CONTROL
1 Fabricate a measuring box for each of the material per design strength using dimensions as stated below.
Table A
Required Volume(ft3) /
Dimension (ft) / Measuring box
Design Strenght(psi) Volume(ft3 Measuring
) b d h box
Option-1 M25
Fine Aggregate(S-1) 0.95 1.0 1.0 0.95 0.95 x1
Coarse Aggregate 2.00 1.0 1.0 1.00 1.00 x2
Option-4 M15
Fine Aggregate(S-1) 1.29 1.0 1.0 0.64 0.64 x2
Coarse Aggregate 2.50 1.0 1.0 1.25 1.25 x2
2 For measuring water, calibrate a pail or container
3 Prior to concrete mixing using 1bagger mixer, determine the actual total moisture of each of the materials.
It is necessary for the adjustment of the water in the design.
4 To ensure that materials are of exact in volume, measure each of the materials using the fabricated
measuring box for every design. Place the measured materials in a sack, 1 bag of cement will have then
a corresponding sack of fine aggregate and coarse aggregate, by this set up a continuous flow of job mixing
well then be expected.
5 The mixer to be used for mixing shall be capable of providing concrete in which the variability of unit
weight of mortar is not more than 0.8% and that of unit coarse aggregate content is not more than 5%
after mixing for 1.5 min with the forced-action type mixer or for 3 min with the tilting type mixer
6 After all of materials of the base concrete are charged into the mixer, the mixing shall be performed for
1.5 min with the forced-action type mixer or for 3 min with the tilting type mixer
7 To check the consistency of the job mix concrete a slump cone will be use.
8 To be adjustment of water control at beginning of placement and during placing, when change in quality
is observed.
tated below.
the materials.
l have then
w of job mixing
ge in quality
Preparation of sample Actual Total Moisture Content determination:
1 Taking sample from stockpiling at least 1kg.
2 Weight the sample and record the weight.
3 Put sample in a container or pan with known weight.
4 Pour denatured alchol on the sample in the contaier or pan with enough amount to dry
the sample.
5 Carefully blend the sample in fire using a landle.
6 After drying allow the sample to cool in a few minutes then weight the dry sample and
record the weight.
7 Compute the Actual Total Moisture follow the sample computation below.
Sample computation of Actual Total Moisture (ATM)
Data:
Weight of Container + Weight of Wet sample = 1178.8 gm
Weight of Container + Weight of Dry sample = ### gm
Weight of Container = 135.00 gm
Computation:
Moisture = 1178.79 - ### = 35.29 gm
Weight of dry sample = 1143.50 - 135.00 = ### gm
Moisture
Actual Total Moisture (%) = x 100
Weight of dry sample
35.29
= x 100
1008.50
= 3.50
