1. ratio, has very high early and

1.

             W/C

Strength
(Mpa)

0.35

20.1

0.4

41.6

0.45

38.7

0.5

41.6

0.55

30.2

0.6

36.2

0.65

19.5

 

This data suggests that there is no relation
between the two variables. The highest value for strength is 41.6 N/mm2, and
that is when w/c is 0.5, and the strength is at its lowest when w/c is 0.65, 19.5
N/mm2.

4 Chemical Admixtures:

Plasticisers are used to reduce the water
cement ratio and to increase strength. They are often made on lignosulphonate,
which is a derivative from wood-processing, and have water reduction between 5%
and 12%. By subsidising the cement constant to reduce the heat of hydration in
mass concrete, plasticisers manage to attain the same workability.

A more effective type of water decreasing
admixtures are super plasticisers. Super plasticisers are also more efficient
due to their more advanced properties. Super plasticisers increase fluidity and
so give flowing, self-levelling and self-compacting properties to concrete. It
also decreases water cement ratio, has very high early and later age strength,
decreases shrinkage and so overall increases durability.

Accelerators improve the level of hydration of
hydraulic cement when mixed with concrete. One example of a type of accelerator
are set accelerating admixtures, these are used to lessen the time needed for
the mixture to become tougher. Hardening accelerators increase the strength by
120% at approximately 24h and 20 degrees. Hardening accelerators are useful
where primary stripping of shuttering or very early entrance to pavement is
necessary.

Set retarders are used for extension of the
time that the cement takes to paste into concrete. This is useful for concrete
that needs to be transported long distances, as well as helping use the
concrete at high temperatures.

 

2.

 

Carbon Content (%)

Maximum Load (KN)

0.10%

9.49

0.40%

12.84

0.85%

18.32

 

 

 

Mild Steel:

This type of steel is mainly used for
re-melting, alloying and the production of steel beams in large numbers. It is
formed by adding low amounts of carbon and silicon. It is cheap and
comparatively easy to manufacture. However, mild steel has relatively low
tensile strength and so isn’t useful for reinforcement and heavy structure
manufacturing.

 

Advantages using mild steel in the construction
industry:

 

·       Recyclable

·       Ductile

·       Weldable

·       Cost effective

·       Can be carburised

·      
 

3.

No

Deflection (mm)

Load (KN)

1

0.9

10

2

2.89

20

3

4.97

30

4

7.33

40

 

 

 

 

 

 

 

In essence, a composite is a material created by
combining two different materials to make use of the properties that all of
those materials have or make an entirely new property that each of the
constituents alone lack.

Examples:

Wood

Concrete

Fibre

 

The concrete slump test is a simple and easy
test that determines the workability or consistency of a specific prepared
concrete mix. This allows us to test the suitability of the concrete for
construction, for example, with ease and little money.

 

 

 

4.

 

No

Material

Length

Length

Length

 

Base

Base

Base

 

 

 

Trial1

Trial 2

Trial 3

Average

Trial 1

Trial2

Trial 3

Average

1

Nylon 66

9.80

9.63

8.78

9.40

4.06

3.28

3.30

3.55

2

Polythene

9.63

9.61

9.63

9.62

4.00

3.98

3.96

11,.94

 

               Nylon 66 at 16C

No

Load
(N)

Deflection
(mm)

1

0

0

2

765

0.507

3

1508

1.245

4

1710

1.471

5

2255

2.045

6

3000

2.886

7

3113

3.009

8

3750

3.788

9

4275

4.506

10

4500

4.85

11

4965

6

`12

4958

7.48

            

 

                 
Nylon 66 at 16C

No

Strain

Stress (MPa)

1

0

6.82

2

0.0041

13.44

3

0.0100

13.44

4

0.0118

15.24

5

0.0164

20.09

6

0.0231

26.73

7

0.0241

27.74

8

0.0303

33.41

9

0.0360

38.09

10

0.0388

40.09

11

0.0480

44.24

12

0.0598

44.17

 

 

 

No

Load (N)

Deflection (mm)

1

62

0.1953

2

192

0.4687

3

258

0.742

4

372

1.016

5

427

1.289

6

472

1.562

7

551

1.836

8

583

2.109

9

615

2.383

10

668

2.656

11

692

2.93

12

732

3.203

13

896

6.76

14

992

9.22

15

849

19.88

16

751

30.82

17

600

37.93

18

452

40.39

19

434

59.8

20

427

80

21

422

100.3

22

424

139.9

23

432

159.9

24

378

180.1

25

324

183.7

 

 

 

 

                                                                                                                     

                                                                                    Polythene
at 16C                

 

 

 

 

 

 

 

 

 

 

                                                                                                  
          

 

 

 

No

Strain

Stress (MPa)

1

0.0016

1.62

2

0.0037

5.01

3

0.0059

6.74

4

0.0081

9.72

5

0.0103

11.15

6

0.0125

12.33

7

0.0147

14.39

8

0.0169

15.23

9

0.0191

16.06

10

0.0212

17.45

11

0.0234

18.07

12

0.0256

19.12

13

0.0541

23.40

14

0.0738

25.91

15

0.1590

22.17

16

0.2466

19.61

17

0.3034

15.67

18

0.3231

11.81

19

0.4784

11.34

20

0.6400

11.15

21

0.8024

11.02

22

1.1192

11.07

23

1.2792

11.28

24

1.4408

9.87

25

1.4696

8.46

 

 

No

Load (N)

Deflection (mm)

1

0

0

2

60

0.046

3

765

0.63

4

1500

1.43

5

1545

1.491

6

2235

2.332

7

2813

3.009

8

2993

3.234

9

3750

4.157

10

4013

4.506

11

4493

5.18

12

4898

6

13

5033

6.54

 

 

 

 

 

 

 

 

 

 

            Nylon66 at
80C

 

 

 

 

 

 

No

Strain

Stress (MPa)

1

0

0

2

0.0004

0.53

3

0.0050

6.82

4

0.0114

13.36

5

0.0119

13.77

6

0.0187

19.91

7

0.0241

25.06

8

0.0259

26.67

9

0.0333

33.41

10

0.0360

35.76

11

0.0414

40.03

12

0.0480

43.64

13

0.0523

44.84

 

 

 

 

 

 

 

 

 

 

Nylon66 at 80C

 

 

 

 

 

 

 

No

Load (N)

Deflection (mm)

1

22.4

0.1465

2

104.8

1.377

3

153.2

2.402

4

200

3.838

5

251.6

5.89

6

300

9.37

7

332.4

14.71

8

349.2

21.68

9

361.6

30.09

10

376

45.06

11

366

60

12

350.8

63.1

13

304

71.1

14

306.8

75

15

342.4

90

16

364

104.9

17

368.8

119.9

18

349.6

130.8

 

 

 

 

 

 

 

 

 

 

 

 

 

Polythene at 80C

 

 

No

Strain

Stress (MPa)

1

0.0012

0.59

2

0.0110

2.74

3

0.0192

4.00

4

0.0307

5.22

5

0.0471

6.57

6

0.0750

7.84

7

0.1177

8.68

8

0.1734

9.12

9

0.2407

9.44

10

0.3605

9.82

11

0.4800

9.56

12

0.5048

9.16

13

0.5688

7.94

14

0.6000

8.01

15

0.7200

8.94

16

0.8392

9.51

17

0.9592

9.63

18

1.0464

9.13

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5.

 

 

 

 

 

 

 

In this experiment the effects of different
amounts of applied force on timber are investigated. We used weights to
increase the load on the timber and used a dial gauge to measure the
extension/deflection. The data from the experiment is shown below.

Deflection (mm)

Load(N)

4.5

0

4.80

125

5.26

250

5.73

375

6.20

500

 

 

 

 

 

Experimentation shows that when timber wood is positioned
vertically, it can have a larger lode exerted onto it, meaning it has a higher
compressional strength. This is because vertical poles transmit forces down
into the ground along their length, parallel to the grain. However, when it is
placed horizontally, it has higher tensile strength. The addition of diagonally
oriented beams can increase the load the horizontal beams can withstand, and so
need to be added to prevent the horizontal beams from snapping.