Bulk Cement FAQs
What is cement?
Cement is the binding agent in concrete, normally the most active component, and usually the most costly. Its selection and proper use are important in obtaining the balance of properties required for a particular concrete mixture and in minimising the cost of that mixture. An understanding of the properties of the available cements and their influence on the properties of the concrete is important for the proper selection and use of these materials. Such understanding requires some familiarity with the chemical and physical characteristics of the cement and of their influence on cement performance.
What is the difference between cement and concrete?
Although the terms cement and concrete are often used interchangeably, cement is actually an ingredient of concrete. Concrete is basically a mixture of aggregates and paste. The aggregates are sand and gravel or crushed stone; the paste is water and Portland cement. Portland cement is not a brand name, but the generic terms for the type of cement used in virtually all concrete. Cement comprises from 10 to 15 percent of the concrete mix, by volume. Through a process called hydration, the cement and a portion of water react and harden into a rocklike mass.
What are the different types of cement and what applications would they be used for?
General Purpose (Portland) GP For general use in all types of building and construction
General Purpose Blended (GB) For general use in all types of building and construction. Early rates of strength gain may be lower than those of Type GP, and curing may be more critical for full strength development.
High Early Strength (HE) Where early strength is a critical requirement (eg for the early stripping of formwork), in very cold weather, in repairs to concrete structures.
Low Heat (LH) Where rise in concrete temperature must be limited to avoid thermal stress (eg in mass concrete construction or in very hot weather). Where moderate resistance to some forms of chemical attack is required.
Shrinkage Limited (SL) Where limiting the drying shrinkage of concrete is necessary for crack control, in road pavements and bridge structures.
Sulfate Resistant (SR) Where high resistance to sulfates is required, eg in sulfate-bearing soils and groundwaters.
White and Off-White In the production of architechtural concrete and concrete products. Normally complies with requirements of AS 3972 for Type GP, GB or HE cement.
Coloured In the production of concrete products, concrete paving and similar applications.
Masonry Mortar in brick, block and stone masonry construction. Unsuitable for use in structural concrete.
Oil-well Grouting gas, oil and other deep bore holes and wells. Normally complies with the relevant specification of the American Petroleum Institute.
High Alumina Cement (HAC) Where high early strength and/or resistance to very high temperatures are required (eg refractory concrete and factory floors).
(Sourced from Standards Australia Guide to Concrete Construction)
What is an aggregate?
Aggregates form up to 80% of the volume of concrete and are therefore an important constituent. At one time they were considered to be inert fillers but we now know that their properties can significantly affect the performance of the material in both its plastic and hardened conditions. Some types of aggregates used are sands, gravels and rocks (crushed or uncrushed) and there are also manufactured aggregates available.
How do I order cement?
By calling our Customer Interface Team on 1300 236 368.
What is the difference between Bagged Cement and Bulk Cement?
We have a broad range of bagged products which are packaged in 5kg to 20kg bags. Our bagged product is available from hardware and landscape suppliers and for larger orders, we will arrange delivery. Bulk cement is delivered to your site in tankers and you will require a silo for storage of the product.
How do I open an account?
Please call our Customer Interface Team on 1300 236 368.
What is the difference between concrete and cement?
Cement is the powder added to concrete that provides the basis for the glue that holds the concrete together. In the simplest form concrete is a mixture of sand and stone, termed aggregate, that is bound together by the paste made up by the cement and water. Modern concrete may also contain Supplementary Cementitious Materials (SCM’s) such as Fly Ash, Slag and Amorphous Silica as well as chemical admixtures.
What is hydration?
The glue gains the properties from a chemical reaction that occurs between the cement and the water. This chemical reaction is called Hydration. It requires a favourable temperature and the presence of water to proceed.
What are the different states concrete during setting
Concrete is described in two different states – Plastic & Hardened State. After mixing, the concrete is in a plastic state, which enables it to be moulded into various shapes. In this state it cannot carry any load. As the concrete sets, it moves to the hardened state.
What is water/cement ratio?
This is the ratio of the total water in the concrete to the cement content. With concrete that has Fly Ash or Slag in it, the cement component is more strictly a cementitious component that includes the cement plus those ingredients. The amount of water used in the calculation includes water from all sources and not merely the water added during batching. Aggregate and fine aggregate in particular can contain a significant quantity of water. The w/c ratio is calculated from the weights of the materials, eg Concrete with 300kg of cement and 180 litres of water has a w/c ratio of 0.6 (i.e. 180÷300 = 0.6).
What is the history of cement?
The term 'cement' is used to describe a range of binding materials, the most common of which are known as hydraulic cements. These have the ability to react with water and harden, to produce a strong, durable product.
The first civilisations to use this type of cement on a large scale were the Babylonians and Ancient Egyptians. They mixed lime, clay and water, or lime, gypsum and water to make concrete and mortar. This was used for structures including the Great Pyramid built some 4500 years ago.
The Romans provided the first major advance on this technology. They found that when lime was mixed with a type of volcanic sand found in the neighbourhood of Mount Vesuvius, at a place called Pozzuoli near Naples, and mixed with water, a strong cement was produced. This was combined with pumice and other aggregates to produce the concrete for aquaducts, harbours and buildings including the Colosseum in Rome (80AD).
In Australia, Portland cement was first produced in 1882 at Brighton, in South Australia.
What is clinker?
A. Clinker production involves the quarrying or dredging of raw materials which are then crushed and ground to a smaller size and once blended in the correct proportions are burned at high temperature in a kiln. The resulting material is cooled in a controlled manner and is called clinker.
How is cement produced?
The clinker is ground to a fine powder with gypsum being added. This fine powder is the cement that is used in concrete.
What are Supplementary Cementitious Materials (SCM’s)?
There are three types of Supplementary Cementitious Materials used in Australia – Fly Ash, Ground Granulated Blast Furnace Slag (GGBFS) and Amorphous Silica (Silica Fume).
Supplementary cementitious materials have been used in building construction for many years. The original term used to describe these materials was pozzolan. Pozzolans are rich in silica and/or alumina and these oxides combine with lime in the presence of water to form compounds that are virtually identical to the compounds in hydrated Portland cement.
What is Fly Ash?
The dust collected in electrostatic precipitators used to clean the flue gases from black coal burning power stations.
What is Slag?
The waste material removed in the operation of blast furnaces in the smelting of iron ore.
What is Amorphous Silica (Silica Fume)?
Naturally occurring deposits or Silica Fume which is very fine particulate matter collected in the refining of silicon metal.
Why do we use Supplementary Cementitious Materials (SCM's)?
SCM’s are wastes or by products from other industries and are available at lower cost than Portland cement. The materials are waste products and it is difficult to find practical, economic and environmentally sensitive ways to dispose of them. It is of great benefit to the environment to utilise such waste materials. SCM’s generally have a positive influence on both the plastic and hardened concrete properties.
What is lime?
Lime is derived from limestone, and is always a calcined or burned form of limestone popularly known as quicklime or hydrated lime.
What is limestone?
Limestone is a general term embracing carbonate rocks or fossils; it is composed primarily of calcium carbonate or combinations of calcium and magnesium carbonate with varying amounts of impurities, the most common of which are silica and alumina. Cement Australia has a limestone mine at East End (near Gladstone).
How do I order ready mixed concrete?
Contact Holcim on 13 1188 or Hanson on 13 26 62
How does Cement Australia deliver by road?
Our pneumatic tankers cover the entire country, employing various configurations including singles, B-doubles and even triple road trains that can carry up to 70 tonnes per load. We are also able to offer re-locatable 150 tonne capacity road super-tankers that satisfy local-site storage demands for large projects.
To meet the highest level of service that our customers demand, our modern fleet of prime movers and tankers are despatched 24hrs per day to locations as far south as Hobart and to the remotest parts of North Queensland and the Northern Territory.
As part of our commitment to the highest standards of operational safety, Cement Australia operates a rigorous fleet replacement programme, has NHVAS mass and maintenance accreditation and employs a comprehensive driver selection, induction and training programme.
Does Cement Australia have access to Rail facilities?
Cement Australia also utilises “ISO” intermodal containers for road/rail distribution of product. This form of transport is a vital part of our long distance haulage strategy and allows "direct to door" deliveries to customers through the transfer of the “ISO” intermodals from rail to road. Some 130 “ISO” containers are in operation, linking depots, terminals and customers. Our rail freight service is further complemented by our investment in large numbers of conventional rail tankers.
In conjunction with various rail service providers, Cement Australia also utilises an extensive range of dedicated rolling stock for the delivery of cement, fly ash, coal, limestone and other raw materials at our various terminal and cement manufacturing facilities.
Where is Cement Australia located?
The many locations of Cement Australia’s manufacturing plants and distribution terminals ensures that our products are within easy reach of our customers, as and when they require them.
Cement Australia’s operations extend across the Eastern Seaboard and take into account markets in Southern and Western Australia.
To view our locations click here.
Does Cement Australia export cement to other countries?
For more information, please contact Customer Interface Team on 1300 236 368.
Where do I find Material Safety Data Sheets for Cement Australia’s bulk products?
MSDS can be found here.