36

CHAPTER 3

MATERIAL PROPERTIES

3.1 GENERAL

The properties of the materials which were used in this study are

presented in this chapter. The materials used were cement, fine aggregate,

coarse aggregate, fly ash, superplasticizers, viscosity modifying agent and

water. The properties of these ingredients were assessed and are given below.

The various proportions of mix adopted for this study are discussed in this

chapter.

3.2 CEMENT

3.2.1 General

Ordinary Portland (Birla super) cement was chosen so that the

influence of Tuticorin thermal power plant fly ash could be studied without

any other intervention. The 53 grade ordinary portland cement was chosen

because of its greater fineness which would have effective hydration and also

secondary hydration.

3.2.2 Properties of Cement

The ordinary portland cement which conforms to IS 12269 –1987

was used for making concrete. The physical properties of cement which was

used for the experimental investigation are given in Table 3.1 and the

chemical composition of the cement is given in Table 3.2

37

Table 3.1 Physical properties of cement

Sl.

No.Characteristics

Test results of

cement used

Requirements as per

IS 12269 – 1987

1 Fineness (retained on

90- m sieve)

8% 10 %

2 Normal Consistency 28% --

3 Initial setting time of

cement

33 minutes 30 minutes (minimum)

4 Final setting time of

cement

125 minutes 600 minutes (maximum)

5 Compressive strength of

cement

56 N/mm2

53 N/mm2 (minimum)

6 Expansion in

Le-chatelier’s method1 mm 10 mm (maximum)

7 Specific gravity 3.15 --

Table 3.2 Chemical composition of cement

Sl.

No.Parameter

Birla Super 53

(as provided by

manufacturer)

Requirements

as per IS 12269 –

1987

1 Calcium oxide (CaO) 60.81% --

2 Silica (SiO2) 19.50% --

3 Alumina (Al2O3) 4.12% --

4 Iron oxide (Fe2O3) 6.06% --

5 Magnesia (MgO) 1.52% max 6.0%

6 Sulphur anhydrite (SO3) 2.48% max 2.5%

7 Insoluble residue 1.51% max 2.0%

8. Total loss on ignition 3.41% max 4.0%

9. Total chloride content (Cl) 0.01% max 0.1 %

10. Available alkali: Na2O 0.05% --

K2O 0.28% --

11. Ratio of % of lime to the % of silica,

alumina and Iron oxide 0.93 0.80 to 1.02

12. Ratio of % of alumina to that of Iron

oxide 0.68 min 0.66

38

Bogues equations were used for estimating the potential compound

composition of portland cement. The equations are applicable to Portland

cement .The equations are as follows:

% C3S = 4.071 CaO – 7.600 SiO2 – 6.718 Al2O3 – 1.430 Fe2O3 – 2.850 SO3

(3.1)

% C2S = 2.867 SiO2 – 0.7544 C3S (3.2)

% C3A = 2.650 Al2O3 – 1.692 Fe2O3 (3.3)

% C4AF = 3.043 Fe2O3 (3.4)

So, these equations were used to find the Bogues compound

composition and are tabulated in Table 3.3.

Table 3.3 Bogues compound composition of cement

Chemical Name Chemical FormulaShort hand

Notation

Weight

percent

Tricalcium silicate 3CaO.SiO2 C3S 56

Dicalcium silicate 2CaO.SiO2 C2S 14

Tricalcium aluminate 3CaO.Al2O3 C3A 1

Tetra calcium alumino

ferrite

3CaO.Al2O3.Fe2O3C4AF 18

3.2.3 Hydration of Cement

The raw material used in the manufacture of Portland cement

consists of lime, silica, alumina and iron oxide. These compounds interact

with one another in the kiln to form a series of more complex products. The

39

relative proportions of these compounds are responsible for influencing the

various properties of cement. Four compounds are usually regarded as the

major constituents of cement. They are tricalcium silicate, dicalcium silicate

tricalcium aluminate and tetra calcium alumino ferrite.

Anhydrous cement does not bind the fine and coarse aggregate. It

acquires cohesive and adhesive property only when water is mixed with it.

The chemical reaction that takes place between cement and water is referred

as hydration of cement. The schematic representation of hydration process is

shown in Figure 3.1.

Figure 3.1 Schematic representation of the formation and hydration of

portland cement

When Portland cement is mixed with water, its constituent

compounds undergo a series of chemical reactions that are responsible for the

eventual hardening of concrete. Reactions with water are designated as

hydration, and the new solids formed on hydration are collectively referred to

as hydration products. Figure 3.2 shows schematically the sequence of

structure formation as hydration proceeds. This involves the replacement of

water that separates individual cement grains in the fluid paste (Figure 3.2a)

with solid hydration products that form a continuous matrix and bind the

40

residual cement grains together over a period of time, as illustrated in

Figure 3.2(b-d). The calcium silicates provide most of the strength developed

by Portland cement. C3S provides most of the early strength (in the first three

to four weeks) and both C3S and C2S contribute equally to ultimate strength

(Neville 1993).

Figure 3.2 Microstructural development in portland cement pastes

(Ref.42)

In commercial cements, the calcium silicates contain small

impurities of some oxides present in the clinker, which have a strong effect on

the properties of the calcium silicate hydrate (C-S-H). Calcium silicate

hydrate is essentially amorphous and develops as a mass of extremely small

irregular particles of indefinite morphology. The particles are so small that

41

they can be studied only by scanning electron microscope and even cannot be

completely resolved.

Tricalcium silicate and dicalcium silicate present in the cement, on

hydration give rise to calcium silicate hydrates and calcium hydroxide as

shown in Equations (3.5) and (3.6).

2 (3 CaO. SiO2) + 6 H2O 3CaO. 2SiO2 3 H2O + 3Ca (OH) 2

Tricalcium silicate Calcium Silicate Hydrates Calcium Hydroxide

(3.5)

2(2 CaO. SiO2) +4 H2O 3CaO. 2SiO2 3 H2O + Ca (OH) 2

Dicalcium Silicate Calcium Silicate Hydrates Calcium Hydroxide

(3.6)

The silica present in the fly ash react with water and Calcium

Hydroxide, produced during the hydration of cement and the principal

product of reaction is calcium silicate hydrate, which is strength forming gel.

3Ca (OH) 2 + 2 SiO2 3CaO. 2SiO2 . 3 H2O

Calcium Hydroxide Silica Calcium Silicate Hydrates (3.7)

3.2.4 Ill Effects of Calcium Hydroxide

In the above reaction, calcium hydroxide is not a desirable product

in concrete mass. It is soluble in water and gets leached out making the

concrete porous, particularly in hydraulic structures. The carbon dioxide

present in the atmosphere reacts with calcium hydroxide in the presence of

moisture to form calcium carbonate. The alkalinity of concrete reduces due to

the formation of calcium carbonate. This will cause corrosion of

reinforcement. Due to these disadvantages of calcium hydroxide, the

reduction in its concentration in concrete will improve the properties of

42

concrete. In this regard, fly ash consumes calcium hydroxide and helps in

reducing its concentration in concrete. The photographs at the interfacial

transition zone are shown in Figures 3.3 and 3.4.

Figure 3.3 SEM photographs of calcium hydroxide crystals in the

interfacial transition zone (Ref.40)

Figure 3.4 Diagrammatic representations of the interfacial transition

zone and bulk cement paste in concrete (Ref.40)

43

3.3 FLYASH

3.3.1 General

Fly ash is one of the most extensively used by-product materials in

the construction field resembling Portland cement. It is an inorganic,

noncombustible, finely divided residue collected or precipitated from the

exhaust gases of any industrial furnace. Most of the fly ash particles are solid

spheres and some particles, called cenospheres, are hollow (Figure 3.5). Also

present are plerospheres, which are spheres containing smaller spheres inside.

The particle sizes in fly ash vary from less than 1 m to more than 100 m

with the typical particle size measuring under 20 m. Their surface area is

typically 300 to 500 m2/kg, although some fly ashes can have surface areas as

low as 200 m2/kg and as high as 700 m

2/kg. Fly ash is primarily silicate glass

containing silica, alumina, iron and calcium. The relative density or specific

gravity of fly ash generally ranges between 1.9 and 2.8 and the colour is

generally gray or tan.

3.3.2 Properties of Fly ash

The properties of Fly ash collected from Tuticorin thermal power

station which was used in the experimental investigation are given in the

Tables 3.4, 3.5 and 3.6 and confirms the specifications given in IS 3812 –

2003. Photograph of Fly ash by Scanning Electron Microscope is shown in

Figure 3.5.

Table 3.4 Physical properties of fly ash

Properties Results

Colour Whitish gray to gray with slight black fines

Bulk density 1.2 g/cc

Specific gravity 1.81

Fineness 2000-2200 cm2/g

Moisture Nil

44

Table 3.5 Chemical properties of fly ash

CompoundsTuticorin fly ash

composition (%)

Acceptable Limits as per

IS 3812-2003 part 1 (%)

SiO2 59.62 Min. 35.0

AlO2 31.08 --

TiO2 - --

Fe2O3 2.92 --

MnO - --

MgO 1.45 Max. 5.0

CaO 1.74 --

K2O - --

Na2O - Max. 1.5

SO3 0.51 Max. 3.0

Table 3.6 Grading of fly ash

IS sieve size (mm) % finer

600 99.8

300 98.8

150 63.2

75 55.9

<75 0

Figure 3.5 SEM photographs of fly ash (Ref.34)

45

3.3.3 Action of Fly ash

Fly ash is subdivided into two classes, F and C, which reflect the

composition of the inorganic fractions. Class F fly ashes are produced from

bituminous and sub bituminous coals and contain as active components

aluminosilicate glasses, whereas class C fly ashes are derived from the lignitic

coals and contain calcium aluminosilicate glasses with the high levels of

calcium oxide, comprised in the glassy fraction. Although their usage is

mainly economic, the addition of fly ash has many technical benefits.

Many class C ashes when exposed to water will hydrate and harden

in less than 45 minutes. In concretes, class F fly ash is often used at dosages

of 15% to 25% by mass of cementitious material and class C fly ash is used at

dosages of 15% to 40%. Dosage varies with the reactivity of the ash and the

desired effects on the concrete. Because of their spherical morphology, when

using fly ash admixtures as replacement material for cement, workability and

long-term strengths are achieved in concretes. In such cases, they act like

small balls to reduce inter particle friction. Fly ash is also used in concrete

mixes in order to reduce the heat of hydration, permeability, and bleeding.

The durability is improved by providing a better sulphate resistance, control

of the alkali-silica reaction, decreased chloride diffusion and reduction of

leaching from the reduction in calcium hydroxide (which is the most soluble

of the hydration products) and changes in pore structure. However, there are

some disadvantages related to the use of fly ash regarding the reduced air-

entraining ability and early strength due to the influence of residual carbon

from the ash.

46

3.4 AGGREGATE

3.4.1 General

Usually the aggregates occupy 70% to 80% of the volume of

concrete and have an important influence on its properties. They are granular

materials, derived generally from natural rock and sands.

3.4.2 Sieve Analysis for Coarse Aggregate

Sieve analysis for coarse aggregates was conducted as per IS 2386

– Part I. From the sieve analysis, fineness modulus of coarse aggregate was

found out. The size of sieves used for analysis are 80 mm, 40 mm, 20 mm,

10 mm, 4.75 mm, 2.36 mm, 1.18 mm, 600 microns, 300 microns

and 150 microns. The fineness modulus of coarse aggregate (12.5 mm) was

found to be 7.48.

3.4.3 Sieve Analysis for Fine Aggregate

The Indian Standard sieves used for the analysis are 4.75 mm,

2.36 mm, 1.18 mm, 600 microns, 300 microns and 150 microns. The fine

aggregate was sieved through the sieves. The weight of sample retained on

each sieve was obtained and the cumulative percentage weight retained was

found out. The fineness modulus of the fine aggregate was found to be 2.27

and the sand was conforming to grading Zone III of Table 4 of IS: 383-1970.

3.4.4 Specific Gravity of Coarse and Fine Aggregate

Specific gravity of aggregates were determined as per IS 2386 –

Part III. The specific gravity of coarse aggregate and fine aggregate were

determined to be 2.81 and 2.66 respectively.

47

3.4.5 Water Absorption of Coarse Aggregate and Fine Aggregates

Water Absorption of aggregate was determined as per IS 2386 –

Part III. Aggregate was washed thoroughly and immersed in water for 24 hrs.

Aggregate was surface dried using cloth so as to bring the aggregate in

saturated surface dry condition. 1000 gram in case of coarse aggregate and

500 gram in case of fine aggregate were exactly weighed and kept in oven at

105 degree Celsius for 24 hours. Final weights of aggregates were measured.

Water absorption was calculated as:

Water absorption (% of dry weight) =[ (Wt of saturated surface dry sample -

Wt of oven dried sample) / Wt of oven dried sample ] 100.

Water absorption of coarse aggregate and fine aggregate were determined as

0.4 % and 2.0 % respectively.

3.4.6 Proportioning of Coarse Aggregate and Fine Aggregate

Fine aggregate and coarse aggregate (12.5 mm size) were

proportioned to get a mixture of maximum density. The proportion of coarse

aggregate and fine aggregate to give a maximum density was found

to be 67: 33.

3.5 SUPERPLASTICIZERS

3.5.1 General

Superplasticizers (high-range water-reducers) are low molecular-

weight, water-soluble polymers designed to achieve high amounts of water

reduction (12-30%) in concrete mix in order to attain a desired slump. The use

of superplastcizer in concrete is an important milestone in the advancement of

concrete technology. Superplasticizers produce a homogeneous, cohesive

48

concrete generally without any tendency for segregation and bleeding.

Superplasticizers are more powerful dispersing agents which make the mix

more cohesive and cement to hydrate completely. The nature of

superplasticizers, their action and their dosage requirements are discussed in

this section.

3.5.2 Nature of Superplasticizers

Fly ash particles are very fine in nature and possess large surface

area. Hence the particles of fly ash which have to be wetted increases the

water demand, so that, in mixes with a low water/cement ratio, it is necessary

to use a superplasticizer. Superplasticizers are water-soluble organic polymers

which have to be synthesized, using a complex polymerization process to

produce long molecules of high molecular mass. A larger molecular mass,

within limits, improves the efficiency of superplasticizers. Their chemical

nature also has an effect. The majority of superplasticizers are in the form of

sodium salts but calcium salts are also produced, the latter have a lower

solubility. There is no generalization about the overall superiority of either

naphthalene or melamine or calcium lignosulfonates or carbohydrate

derivatives are possible, probably because more than one property of a

superplasticizer affects its performance and also because of the chemical

properties of the cement and fly ash used play a role as well.

3.5.3 Effect of Superplasticizers

Water-reducing admixtures are negatively charged organic

molecules that adsorb primarily at the solid-water interface, whereas solid

particles carry residual charges on their surfaces, which may be positive,

negative or both. In cement paste, opposing charges on adjacent particles of

cement can exert considerable electrostatic attractions, causing the particles to

flocculate (Figure 3.6a). A considerable amount of water is tied up in these

49

agglomerates and adsorbed on the solid surfaces, leaving less water available

to reduce the viscosity of the paste and hence that of the concrete. Molecules

of the water-reducing admixtures interact to neutralize these surface charges

and cause all surfaces to carry uniform charges of like sign. Particles now

repel each other, rather than attract, and remain fully dispersed in the paste

(Figure 3.6b), thus, most of the water is available to reduce the viscosity of

the paste and of the concrete, because of air-detraining properties of

superplasticizers, an air entraining agent must be added to the concrete to get

a stable air void system before a superplasticizer is added.

Figure 3.6 Dispersing actions of water-reducing admixtures

(a) Flocculated paste (b) Dispersed paste (Ref.42)

3.5.4 Dosage of Superplasticizers

For increasing the workability of the mix, the normal dosage of

superplasticizers is between 0.8 and 1.3 % of weight of cement. The dosage of

superplasticizer influences the viscosity of the grout and hence the

50

workability of concrete. The effectiveness of a given dosage of a

superplasticizer depends on the water cement ratio of the mix. Specifically, at

a given dosage of the superplasticizer, the percentage water reduction which

maintains a constant workability is much higher at low water cement ratios

than at high water cement ratios.

3.5.5 Superplasticizers used in this Study

Three superplasticizers used in this study were,

SP1 - Polycarboxylic ether based superplasticizer

SP2 - Melamine sulphonated based superplasticizer

SP3 - Naphthalene sulphonated based superplasticizer

3.6 VISCOSITY-MODIFYING AGENT

3.6.1 General

Viscosity modifiers are high molecular-weight, water-soluble

polymers used to raise the viscosity of water. Such compounds increase the

cohesiveness of fresh concrete, reducing its tendency to segregate and bleed.

3.6.2 Effect of Viscosity-Modifying Agent

They work by attaching their long molecules to the water

molecules, process which inhibits the free displacement of water. These

agents are helpful in improving the properties of lean concretes with low

cement contents, concrete placed under water and concretes or grouts that are

placed by pumping. In the latter case, they reduce pumping pressures through

improved lubricating properties, as well as reducing segregation tendencies.

When compounds in this category are used to improve the cohesiveness of

concrete being placed underwater, they are classified as antiwashout

51

admixtures. Viscosity-modifying agents are added in concretes used in places

with extreme congestions due to reinforcement configurations or unusual

geometry forms, where fluid but cohesive concrete is required in order to

resist bleeding and segregation.

The materials commonly used are polyethylene oxides, cellulose

ethers, natural gums, and polyacrylamides or polyvinyl alcohol. Other

materials used are finely divided solids such as clays and lime, but they tend

to reduce the strength of the concrete and for these reasons they are primarily

used in grouts when strength is not of major importance.

3.6.3 VMA used in this Study

Three Viscosity Modifying Agent used in this study were,

VMA1 - Biopolymer

VMA2 - Carboxyl Methyl Cellulose

VMA3 - Organic aqueous solution

3.7 CONCRETE MIX DESIGN

3.7.1 General

The selection of suitable ingredients of concrete and the

determination of their relative proportions were done with an aim to produce

concrete of required strength and durability as economical as possible. Based

on the properties of cement, fine aggregate, coarse aggregate and water, the

mix proportion was calculated by adopting IS 10262 – 1982.

After determining material properties, mix for M25 and normal

concrete was designed and the mix for Self Compacting Concrete was fixed

by reducing coarser fractions and increasing finer fractions by the addition of

52

fly ash. Different admixtures in the form of HRWR and VMA were added to

the fly ash concrete to obtain Self Compacting Concrete and their properties

were studied in the fresh and hardened state.

3.7.2 Mix Design for Normal Concrete

Mix design for normal concrete was done by using Indian standard

method. Trial mixes were cast to obtain economical mix and details of final

mix arrived at are given below:

Design stipulation

i. Characteristic compressive strength - 25 N/mm².

ii. Maximum size of aggregate - 20 mm.

iii. Degree of workability - 0.9 C.F.

iv. Degree of quality control - Good

v. Type of exposure - Moderate

Design procedure

Target mean strength of concrete = 25+1.65×4

= 31.6 N/mm²

w/c for strength = 0.525

w/c for Durability = 0.5

w/c adopted = 0.5

Water content including surface water

per m³ of concrete = 186kg

53

Sand as percent of total aggregate by

absolute volume = 35%

Required sand content as percentage of

total aggregate by absolute volume

after corrections = 35-3.5

= 31.5%

Required water content after applying

suitable corrections = 186 + 5.58

= 191.58 kg

Cement content = 191.58/0.5

= 383.16 kg/m³

Minimum cement content for

moderate exposure = 300 kg/m³

Hence adequate

Fine aggregate content = (1000-0.02-191.02-

424.49/315)×0.315×2.66

Fine aggregate = 576 kg

Coarse aggregate = 1290.24 kg

Mix proportion (by mass) 1:1.50:3.36

Trial mixes were cast to obtain economical mix satisfying

workability and strength requirements and details of final mix arrived at are

given below.

Mix proportion – 1:1.74:3.64 w/c ratio = 0.5

54

The material required for M25 grade normal concrete are presented

in Table 3.7

Table 3.7 Mix detail of M25 grade normal concrete

S.No. Materials Quantity (kg/m³)

1 Cement 350

2 Fly ash -

3 Fine aggregate 610

4 Coarse aggregate 1275

5 Water 175 lit.

6 Slump in mm 50

7 Compacting Factor 0.90

828 days compressive

strength in N/mm²34.940

3.8 MIX PROPORTION FOR SELF - COMPACTING

CONCRETE

3.8.1 General

Self - compacting concrete requires more powder content for more

flowability. Therefore the coarse aggregate content is reduced while

increasing the fine aggregate and fly ash is also added while keeping the

cement content same as that of normal concrete. Water content was adjusted

to suit the particular dosage of VMA and HRWR.

A detail of mix for 40% of fly ash by total binder was fixed and

materials required for 1 m3 of SCC are presented in Table 3.8.

55

Table 3.8 Materials required for one cubic metre of self - compacting

concrete

Materials Quantity(kg/m³)

Cement 350

Fly ash 234

Fine aggregate 875

Coarse aggregate 700

3.8.2 Mix Design for Self - Compacting Concrete

Concrete mix M25 having characteristic strength of 25 MPa was

examined. The mix proportioning was carried out by using the guidelines

given by EFNARC, in the absence of any codal recommendation, for

designing self compacting concrete.

Self - compacting concrete requires more powder content for more

flowability. The fines or the powder (all material less than 0.1mm) play a

decisive role for the proportioning of self compacting concrete. The powder

type of self - compacting concrete should have a reduced water-powder ratio.

This means that, the powder content should be more (cement+fillers+fines

from the aggregates) and is usually in the range of 500 to 600 kg/m³. Out of

this, the cement content can vary from 300 to 450 kg/m³ (as per BIS) and the

remaining is to be replaced by fly ash. Also the quantity of coarse aggregate is

reduced while fine aggregate is increased in self - compacting concrete. Trial

mixes were carried out with 25%, 30%, 35%, 40%, 45%, and 50%

replacement of cement by fly ash in the total powder to fix water to

cementitious material ratio (w/cm) by slump flow test. Cement content, for

each varying fly ash percentage, was obtained to suit replacement level and

the details of self - compacting concrete mix adopted is reported in Table 3.9.

56

Table 3.9 Materials required for one cubic metre of self - compacting

concrete

Sl.No Material FA25 FA30 FA35 FA40 FA45 FA50

1 Cement 438.00 408.80 379.60 350.40 321.20 292.00

2 Fly ash 146.00 175.20 204.40 233.60 262.80 292.00

3 Fine

Aggregate875.00 875.00 875.00 875.00 875.00 875.00

4 Coarse

aggregate700.00 700.00 700.00 700.00 700.00 700.00

3.9 FIXING WATER/CEMENTITIOUS MATERIAL RATIO

FOR SCC

A total of five different admixture combinations were tried with

different dosages. Slump flow test was carried out for each mix and the mix

which gave satisfactory flow value was chosen for the study on the properties

in fresh state and hardened state.

3.9.1 PCESP

Mixes PCESP1, PCESP2, PCESP3, PCESP4 and PCESP5 were

prepared by varying the dosage of PCE (HRWR) from 0.8 to 1.3% by weight

of cement.

3.9.2 Biopolymer

Mixes were prepared by varying the dosage of biopolymer for 0.35

and 0.40% by weight of total binder.

57

3.9.3 PCESP + Biopolymer

Varying the dosage of PCESP (HRWR) and Biopolymer (VMA)

different trial mixes as Table 3.10 were prepared and their performance was

studied.

3.9.4 MSSP + Carboxyl Methyl Cellulose

Varying the dosage of Carboxyl Methyl Cellulose (VMA) and

MSSP (HRWR) only two trials were carried out as given below.

3.9.5 NSSP + Organic Aqueous Solution

Varying the dosage of NSSP (HRWR) and Organic aqueous

solution (VMA) different trials were made as table presented in Table 3.10.

3.10 PROPERTIES OF SELF – COMPACTING CONCRETE

3.10.1 Fresh State

To determine the self - compactability of concrete, Slump flow test,

L-box test, U-box test and V-funnel test were conducted after fixing w/cm

ratio for each mix and the results are reported.

3.10.2 Hardened state

The mix which satisfied the properties in fresh state were chosen

for the determination of compressive strength in hardened state.

Three cubes of size 150×150×150 mm each were cast for the

determination of compressive strength at the age of 7 and 28 days for the

chosen mix and the results are reported in chapter 5.

58

Table 3.10 Mix proportions with various HRWR and VMA

ComponentsPCE

SP 1

PCE

SP 2

PCE

SP3

PCE

SP 4

PCE

SP 5BP1 BP2

PCESP+

BP3

PCESP+

BP4

PCESP+

BP5

MSSP

+CMC1

MSSP

+CMC2

NSSP

+AS1

NSSP

+AS2

Water

content in

litres

210 207 205 199 205 204 234 216 219 234 234 222 234 245

w/cm ratio 0.36 0.355 0.35 0.34 0.35 0.35 0.35 0.37 0.375 0.40 0.4 0.38 0.4 0.42

w/p ratio

(by volume)0.87 0.86 0.85 0.83 0.85 0.85 0.85 0.87 0.85 0.92 0.90 0.97 0.91 0.97

HRWR % by

wt of cement0.8 1.0 1.1 1.2 1.3 --- --- 1.0 0.9 0.8 1.25 1.5 0.65 0.75

HRWR in

litres2.8 3.5 3.85 4.2 4.55 --- --- 3.5 3.15 2.8 4.38 5.25 3.8 4.4

VMA % by

wt of total

powder

--- --- --- --- --- 0.35 0.40 0.1 0.15 0.2 1.0 1.1 0.75 0.5

VMA in

litres--- --- --- --- --- 2.04 2.34 0.58 0.88 1.17 3.5 3.85 4.4 2.9