Our clientele are always genuine cement buyers, traders and brokers and contracts are generally comprised of regular monthly shipments over 12 months or longer. The price generally varies related to the quantity ordered, the type of cement, packaging and the payment method offered.
The price can also be increased by various Government Bureau of Standards regulations such as SABS in South Africa, so we need to know destination in your initial enquiry.
Shipment sizes are 12,500 mt, 25,000 mt and 50,000 mt and contracts are in any combination thereof.
Packaging options are Bulk (loose shiploads) or Bulk 1 ton and 1.5 ton Bulker Bags or 50 kg Bags.
What is Cement?
Cement is the main binding ingredient in concrete, the most common building and construction material in the world. Major uses include new housing, commercial office facilities, manufacturing, mining and tourism facilities, and infrastructure development such as roads, airports, bridges, harbours and reservoirs.
Cement is made from a mixture of calcium carbonate (generally in the form of limestone), silica, iron oxide and alumina.
A high-temperature kiln fuelled by coal, natural gas or alternative fuels (waste tyres, oils and solvents) heats the raw materials to a partial melt at 1450°C, transforming them chemically and physically into clinker. This grey pebble-like material comprises the special compounds that give cement its binding properties. Clinker is mixed with gypsum and ground to a fine powder to make cement.
ORDINARY PORTLAND CEMENT
We offer our product Ordinary Portland Cement 42.5 Type I as per specifications as below, however we can also supply OPC 52.5 and OPC 32.5 and other specialist cement products provided the quantities above our minimums.
Portland cement is the most common type of cement in general usage, as it is a basic ingredient of concrete, mortar and most non-speciality grout.
The most common use for Portland cement is in the production of concrete. Concrete is a composite material consisting of aggregate (gravel and sand), cement, and water. As a construction material, concrete can be cast in almost any shape desired, and once hardened, can become a structural (load bearing) element.
TYPES OF PORTLAND CEMENT
Different types of Portland cement are manufactured to meet different physical and chemical requirements for specific purposes. The American Society for Testing and Materials (ASTM) Designation C 150 provides for eight (8) types of Portland cement:
Type I is a general purpose Portland cement suitable for all uses where the special properties of other types are not required. It is used where cement or concrete is not subject to specific exposures, such as sulphate attack from soil or water, or to an objectionable temperature rise due to heat generated by hydration. Its uses include pavements and sidewalks, reinforced concrete buildings, bridges, railway structures, tanks, reservoirs, culverts, sewers, water pipes and masonry units.
Type II Portland cement is used where precaution against moderate sulphate attack is important, as in drainage structures where sulphate concentrations in ground waters are higher than normal but not unusually severe. Type II cement will usually generate less heat at a slower rate than Type I. With this moderate heat of hydration (an optional requirement), Type II cement can be used in structures of considerable mass, such as large piers, heavy abutments, and heavy retaining walls. Its use will reduce temperature rise – especially important when the concrete is subject to hot weather.
Type III is a high-early strength Portland cement that provides high strengths at an early period, usually a week or less. It is used when forms are to be removed as soon as possible, or when the structure must be put into service quickly. In cold weather, its use permits a reduction in the controlled curing period. Although richer mixtures of Type I cement can be used to gain high early strength, Type III, high-early-strength Portland cement, may provide it more satisfactorily and more economically.
TYPE IA, IIA, IIIA
Specifications for three types of air-entraining (carrying air particles along in its flow) portland cement (Types IA, IIA, and IIIA) are given in ASTM C 150. They correspond in composition to ASTM Types I, II, and III, respectively, except that small quantities of air-entraining materials are interground with the clinker during manufacture to produce minute, well-distributed and completely separated air bubbles. These cements produce concrete with improved resistance to freeze-thaw action. Chemically and physically similar to Type I cements except they are ground finer to produce higher early strengths.
Type IV is a low heat of hydration cement for use where the rate and amount of heat generated must be minimized. It develops strength at a slower rate than Type I cement. Type IV portland cement is intended for use in massive concrete structures, such as large gravity dams, where the temperature rise resulting from heat generated during curing is a critical factor.
Type V is a sulphate resisting cement used only in concrete exposed to severe sulphate action — principally where soils or ground waters have a high sulphate content. Low Tricalcium Aluminate (C3A) content, generally 5% or less, is required when high sulphate resistance is needed.
SPECIAL NOTE: For concrete pipe and precast box manufacturing, Type I or II cements are generally used.
WHITE PORTLAND CEMENT
In addition to the eight types of portland cement, a number of special purpose hydraulic cements are manufactured. Among these is white portland cement. White portland cement is identical to grey portland cement except in colour. During the manufacturing process, manufacturers select raw materials that contain only negligible amounts of iron and magnesium oxides, the substances that give grey cement its colour. White cement is used whenever architectural considerations specify white or coloured concrete or mortar.
OIL WELL CEMENTS
Oil-well cements, used for oil wells grouting, often called oil-well cementing, are usually made from Portland cement clinker or from blended hydraulic cements.
Oil-well cements are used for cementing work in the drilling of oil wells where they are subject to high temperatures and pressures. They usually consist of portland or pozzolanic cement with special organic retarders to prevent the cement from setting too quickly.
Generally Oil well Cements must be slow-setting and resistant to high temperatures and pressures. The American Petroleum Institute Specifications for Materials and Testing for Well Cements (API Specification 10A) includes requirements for eight (8) classes of oil-well cements (classes A, B, C, D, E, F, G, H) and three (3) grades (Grades O – ordinary, MSR – moderate sulphate resistant, and HSR – high sulphate resistant). Each class is applicable for use at a certain range of well depths, temperatures, pressures, and sulphate environments. The petroleum industry also uses conventional types of Portland cement with suitable cement-modifiers. Expansive cements have also performed adequately as well cements.
Origin of our cement is Ukraine, Russia, CIS, China, India, Indonesia, Mexico, Brazil – Seller’s option.
GREY PORTLAND CEMENT FOR CONSTRUCTION GRADE 42.5 N/R
GREY PORTLAND CEMENT CONSTRUCTION GRADE 42.5
ACCORDING TO BRITISH AND SABS STANDARDS DIN EN 197-1/2000 OR ASTM C 150
Silicon Dioxide (SiO2) 20.8 – 21.5
Aluminium Oxide (Al2O3) 5.30
Ferric Oxide (Fe2O3) 3.25 – 3.5
Calcium Oxide (CaO) 65.60
Magnesium Oxide (MgO%) 1.7 – 3.0
Sulphur Trioxide (SO3) 2.7 – 3.0
Loss Of Ignition (LOI) 1.8 – 3.0
Insoluble Residue % 0.1 – 0.7
Tricalcium Silicate (C3S%) 50.0 – 54.4
Dicalcium Silicate (C2S%) 14.2 – 18.2
Tricalcium Aluminate (C3A%) 6.0 – 6.8
Tricalcium Alumino Ferrice (C4AF%) 11.6
Chromium (Cr%) 2.0 Max.
PHYSICAL AND MECHANICAL PROPERTIES
Blain CM2/GR 3.250
Autoclave Expantion 0.02
Normal Consistency % 27.5
Initial Setting Time (Hours:Mins) 3.25 – 4.50
Hard Set (Hours:Mins) 4.54 – 6.00
Fitnes index (CM2/GM) 2800 – 3040
COMPRESSIVE STRENGTH ISO/EN 197-1/2000 BS 4550 MORTAR
@ 03 DAYS 2.65 – 34.2 KG/CM2
@ 07 DAYS 37.3 – 42.5 KG/CM2
@ 28 DAYS 52.8 – 54.6 KG/CM2