Cement and Lime

What material are use for adulteration of cement?

·        Quarry dust

·        Sand

·        Silt

        Clay

·        Pozzolana

What Brand of cement are available in Sri Lanka market?

·        Holcim

·        Ruhunu

·        Mahaweli Marine

·        Tokyo

·        Ceylon Ambuja

·        Samudura

·        Lafarge

·        Ultratech

What is printed on cement bag and explain the meaning?

1.     Net wt 50kg – Net weight of cement is 50 kg

2.     SLS 107 – In Sri Lanka its quality is certified with SLS 107 product certification

3.     Ordinary Portland Cement – Type of Cement

4.     ISO 9001 – Manufactured by an ISO 9001 Certified company.

5.     Strength Class 42.5N – Normally compressive strength is 42.5 in 28 days

6.     Manufactured Date

7.     Packing Date

8.     Please use before 90 date from packing

9.     Maximum  retail Price

1        Brand Name

1    Manufactured Company name and address

How we identify quality of lime ?

Quality lime should possess following characteristics

·        Freedom from cinders and Clinkers , with not more than 10% of other impurities.

·        It should be in hard lumps, with but little dust .

·        It should slake readily in water , forming a very fine smooth past without any residues.

·        It should dissolve in soft water .

How we identify is it hydraulic or non-hydraulic lime?

Hydraulic lime sets by hydrolysis whereas non- hydraulic lime sets by carbonation . The hydraulic lime can set under water , that’s because hydrolysis is reaction caused by water. The non- hydraulic lime needs air to carbonate and thus set.  

In physical terms, the two materials are very different to work with hydraulic lime is available as a bagged powder whereas the non-hydraulic lime is a putty.

Non- hydraulic lime is softer and set must slowly. The carbonation process is very slow and the material remains soft and flexible.

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