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Ohorongo Cement Product Types

CEM I 42.5R

CEM I 42.5R

Used by Brickmakers due to the high early strength. Also used for “special blended mixes’’ where other cementitious additives should be added to obtain prescribed properties.



Used by retailers, small construction companies and common applications around the house (plastering and small renovations).



Used by batching plants for a high range of ready-mix concrete.

CEM II B-V 42.5N

CEM II B-V 42.5N

Ideal for use at the coast, higher resistance against moisture penetration and chloride enriched environment (sea water).

Indicators on Ohorongo Cement

The description of the different cement types is made up of different sections:

Portland-composite cement (MAIN CEMENT TYPES). Indicates from which of the 5 main cement types the specified cement comes.

The main types produced by Ohorongo Cement are:
  • CEM I = Portland cement
  • CEM II = Portland composite cement

Indicates how much constituents is added in %, and the second letter indicates which kind of constituent was used. The amount added in % is symbolized by the letters A, B or C. They indicate different percentages in different cement types.
For example:
“CEM I”   -    No letters, because it consists of 95-100% clinker and 0-5 % minor additional constituents
“CEM II”  -    A = Indicates that the product has been extended with 6-20 % additional constituents
                      B = Indicates that the product has been extended with 21-35 % additional constituents

The type of constituent is indicated by the following abbreviations/letters:

“V”      -  Siliceous Fly-Ash
“L”      -  Limestone with only up to 5% organic material
             (Low grade)
“LL”    -  Limestone with only up to 2% organic material
             (High grade)

Indicates the compressive strength of the cement in MPa after 28 days. The three strength categories are 32.5, 42.5 and 52.5.

Indicates which early strength the cement has. There are three different types of early strengths, L, N & R; however only two are used in Southern Africa (N & R).

  1.  “N” stands for ordinary (normal) early strength
  2. “R” stands for high (rapid) early strength

The parameters for these classifications are determined in the SABS SANS 50197-1 and NAMS 197-1.

Ohorongo Cement is ISO 14001:2015 certified, confirming its commitment towards sustainability and caring for the environment.
Ohorongo has replaced over 40% of its fossil fuel with locally sourced environmentally friendly fuels such as wood chips and charcoal fines to reduce its carbon footprint.
Water consumption is minimised by using air for clinker cooling.
Multiple filters are installed over the entire process to limit dust emissions.
Other important factors


Aggregate have a significant influence on strength, quality and durability of concrete, mortar and plaster. We recommend using aggregates from reputable suppliers.


The sand used should not contain organic material (dung, roots, leaves), nor too much fines / clay, which may lead to loss of strength or excessive water demand.


Quality of water is important!

Use clean drinkable water to achieve a workable concrete. Least amount of water should be used, too much water will result in strength loss of concrete, plaster and mortar.


After the concrete, mortar and plaster have hardened, keep them moist by spraying with water and covering with light coloured plastic sheeting to prevent evaporation for up to 7 days.

Ohorongo Cement is distributed in 50 kg bags, 2 ton bags and bulk tankers. Bulk storage silos should be dry and vapor tight. Cement bags should be protected from moisture and kept dry, preferably off ground by means of pallets or timber, preventing moisture contact. Bags should be stored away from direct sunlight, or should be covered by a roof or sheeting. Stacking should be kept to a maximum of two pallets high to avoid compaction of cement bags at the bottom.

Handling and Safety

Refer to Ohorongo Cement Safety Data Sheet, obtainable from Ohorongo Cement.

Technical Support

Ohorongo Cement offers technical support from its comprehensively equipped chemical, cement, and concrete laboratories. Assistance with cement- as well as concrete aspects, including advice on mix design is available from our qualified technical staff.

Cement Plant
Sargberg Plant, North Otavi
PO Box 444, Tsumeb
Tel: +264 67 235 7000
Fax: +264 67 235 7070


Please contact the Ohorongo Cement Sales Office for price enquiries. Contact details provided below.



Ohorongo Haus
Schanzenweg 35, Windhoek
PO Box 86842, Eros Windhoek 
Tel: +264 61 389 300
Fax: +264 61 247 878

Categories: Guides

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Ohorongo (Pty) Ltd. is one of the first of Namibia's cement manufacturers and owns one of the most modern cement plants in Africa. It was constructed over the course of two years by leading international engine...

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Ohorongo Windhoek Office
11 Van Der Bijl Street, Northern Industrial Area, Windhoek
P.O. Box 86842, Eros
Tel: +264 61 389 300

Cement Plant
Sargberg Plant, North Otavi
P.O.Box 444, Tsumeb
Tel: +264 67 235 7000

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