Assignment 228

Marble manufacturing process and testing

The three major manufacturing processes that marble undergoes are:

· Marble mining

· Arrival and unloading of marble blocks

· Marble cutting

1. Marble mining

This manufacturing process involve extracting the marble from the quarry, either open cast quarry or underground quarry using the diamond wire saw cutting machine as explained in deliverable 1, the marble blocks are extracted with varying sizes. The extracted blocks are classified in terms of block size, tone, cleanliness, amount of streaks and cracks(Long 2017). The advantage of this process is that it allows for the extraction of the valuable marble from the quarry for use in construction and for decoration purposes. The disadvantage associated with it is the workers many end up getting severe injuries or losing their lives during the process.

2. Arrival and unloading of marble blocks

After extraction of the marble block sin the quarry sites, they are then transported to the next site where the blocks are going to undergo further processing.

The blocks are normally transported with Lorries and during the loading and unloading process, cranes are used due to the large size of the blocks and their heavy weight. The blocks are normally stored outdoors in the marble block yard awaiting for the next processing phase. The advantage of this process is that it allows the marble blocks to be ferried to the next site where further processing can be done. The disadvantage is that it raises cost of production(Liguori, Rizzo et al. 2008).

Fig 1: A lorry carry marble blocks in the next site(David 2018)

Fig 2: unloading of marble block using crane (David 2018)

3. Marble cutting

This process involves cutting the huge block of the marble into small sizes as per the requirement. Various types of machines are used, for example, to produce slabs. Multiwire cutters are used and to produce strips, block cutters are used. The maximum width for slab various between 1.8 and 2m, and the maximum thickness is1.5cm. For strips, maximum thickness ranges between 0.9 cm and 2cm, with sizes ranging from 30.5cm by 30.5 cm to 60cm by 60cm (David 2018). The advantage of this process is that it allows the huge marble blocks to be reduced into usage sizes. Its disadvantages are, during the process, some marbles end up going to waste and also during the cutting process, some may get injured.

Material testing for marble

Tensile testing was done a marble strip using a universal testing machine. The specimen which was used for testing is shown below.

Fig 3: Tensile testing specimen (Marble strip)

The ASTM D 638-03 tensile testing standard was used. The specimen was objected to varied stresses in the testing machine and observations were made. It was observed that at 30 MPa, the specimen got fractured. The data collected during the experiment was tabulated as follows.

Table 1: Data collected during the experiment

The graph below shows variation of strain against stress during the experiment.

Conclusion

Because the specimen was brittle, it got fractured at 30MPa and the experiment ended there.

It was also noted that the strain cause by a specific stress was very minimal, this was attributed to less tensile strength of the specimen.

References

Strain vs Strain for marble strip

Series 1 5 10 15 20 25 30 0.1 0.3 0.5 2 2.5 3 Column1 5 10 15 20 25 30 Column2 5 10 15 20 25 30

Stress (MPa)

Strain (mm)

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