Cement

Mastercrete is for use in concretes, mortars, renders and screeds.

For specified concrete refer to BS 8500: Concrete – Complementary British Standard to BS EN 206-1, which provides guidance for different types and classes of cement.

Reference should also be made to the following documents:

BS 5628: Part 3: Use of Masonry.
BS EN 13914-1 Design, preparation and application of external rendering and internal plastering.

Sulfacrete should be used where increased resistance to sulfates is required.

• Consistent strength meeting all the conformity criteria in BS EN 197-1.
• Contains cement quality improver to give the following benefits compared with ordinary Portland cement: lower water demand, more cohesive mix, less tendency for water to segregate and bleed and enhanced resistance of hardened concrete or mortar to freeze/thaw attack.
• Mastercrete entrains a controlled quantity of air and the addition of admixture of the air-entraining type is unnecessary and not recommended for concrete. In mortar and rendering, the addition of proprietary air-entraining mortar plasticiser is either unnecessary or the manufacturer’s recommended dosage significantly reduced dependant upon the sand used. Other proprietary admixtures of the non air-entraining type and pigments are compatible with Mastercrete. Trial mixes are recommended to determine optimum mix proportions.

Mastercrete is supplied in 25 kg bags throughout the United Kingdom.

Mastercrete is a cement based material and should be handled and stored with care. This product may be stored, unopened in either indoor or outdoor conditions. Information on the maximum storage period can be found on the bag.

• Mastercrete may be used in the range of traditional nominal mixes as for traditional Portland cement.
• To achieve optimum performance from Mastercrete in concrete or other products, it is essential that it is correctly specified and used.
• Recommended mixes are given in the Lafarge Cement Builders’ Guide, available from the contacts below.
• As with other cements in building work, there is no substitute for good practice and workmanship. It is essential to use the correct materials, proportion and mix the materials properly, add the correct amount of water, compact, cure and protect as appropriate. When using CEM II cement, it is particularly important to ensure that effective curing is applied.
• Normal hot and cold weather practice should also be followed.
• The final finish quality of this material will depend upon the operative having the required skills and a familiarity with the material and its application methods.
• Lafarge Cement UK cannot be held responsible where workmanship has not been carried out in accordance with good practice.
• Manual handling should comply with The Manual Handling Operations Regulations 1992.
• Mastercrete CEM I is manufactured from natural products, and slight shade variations may occur. Mastercrete CEM I will also have shade variations from differing manufacturing centres.

Further information or specification advice on Mastercrete and the full range of Lafarge cements can be obtained from the contacts listed.

Contact between cement powder and body fluids (eg sweat and eye fluids) may cause irritation, dermatitis or burns. Cement is classified as an irritant under the Chemicals (Hazard Information and Packaging) Regulations.

For further information, including control of soluble hexavalent chromium, refer to the appropriate Lafarge Cement Health and Safety Information Sheets.

Note: Both BS 8500 and BRE Special Digest 1 currently restrict the use of concrete containing Portland limestone cement to Design Sulfate Class DS-1 exposure conditions.