Portland cement is an eco friendly material. It has the potential to reduce the carbon footprint of building construction by up to 1.5 tons per ton of Portland cement used. That’s because each ton of portland cement manufactured uses up to 4.7 million BTU’s of energy and releases up to one ton of carbon dioxide into the atmosphere during the production process.

The manufacture and use of Portland cement contributes significantly to our environmental footprint:

• The consumption of fuel, primarily coal, for firing kilns to produce clinker is a significant source of CO2 emissions

• The combustion of fossil fuels accounts for approximately 60% to 70% of the total energy consumed in cement production process

• CO2 emissions from the calcination reaction and energy consumption are among the main contributors to the environmental impact of cement production

• Cement production has been identified as one of two product manufacturing industries with the highest levels of CO2 emissions per unit weight of output

Portland cement’s ability to reduce greenhouse gas emissions is a result of its low embodied energy (the amount required for its manufacture and distribution) and its high compressive strength (making it suitable for use in most concrete applications).

Portland Cement is not only a sustainable material that can be used in most

Portland cement is the most widely used building material in the world. It is used as a basic ingredient of concrete, mortar, stucco and non-specialty grout. Portland cement is produced by heating limestone or chalk with clay or shale to a high temperature (about 1450 C) in a rotary kiln, and then grinding the resulting clinker to a fine powder. The addition of water produces a paste that hardens and becomes strong to bind the aggregate particles together into a solid mass.

Durable, strong and versatile, portland cement has remained the preferred choice of construction professionals since its invention nearly 200 years ago. As construction technology continues to improve, so too has portland cement’s ability to reduce greenhouse gas emissions while maintaining its performance and durability characteristics.

Portland cement production accounts for approximately 5% of global greenhouse gas emissions according to the Intergovernmental Panel on Climate Change (IPCC). It has been estimated that during its manufacture per tonne of portland cement emitted approximately 0.8 tonnes of CO2 – about one third from the energy required for calcination (the heating up of the raw materials) and about two thirds from fuel combustion.

Portland cement is the key to the world’s most used man-made material. It is used in concrete, which in turn forms the basis for the roads, bridges, buildings and runways that are essential to a modern economy. Without it everything literally grinds to a halt.

But how green is Portland cement? And what can be done to reduce its greenhouse gas emissions? This blog examines Portland cement and how we can make it more eco friendly.

Portland cement was invented by Joseph Aspdin in 1824. His basic recipe has been used ever since: limestone and clay heated at 1,450 degrees centigrade until they fuse into a new substance called clinker. The clinker is ground with gypsum to create Portland cement which can be made into concrete by mixing with water and aggregates (sand, gravel and sometimes recycled materials).

Portland cement is the world’s most widely manufactured material – over three billion tonnes are produced annually. There are also over 200 types of Portland cement which are tailored to meet specific needs such as faster drying or slower setting times.

Portland cement is the world’s most common construction material. It is used in every type of structure, from the tallest skyscrapers to the longest bridges. Portland cement is one of the most important raw materials for low carbon concrete. The production of Portland cement accounts for about 8% of global emissions of carbon dioxide each year.

A large amount of CO2 emissions in the Portland cement manufacturing process comes from decomposition of limestone during clinker production. In a typical modern cement plant, 65% to 70% of energy input goes into process heating, while 25% to 30% is used for power generation. The use of alternative fuels and byproducts materials (AFR) helps to reduce energy consumption and CO2 emissions in several ways:

• By reducing the need for fossil fuel burning

• By reducing raw materials and clinker inputs

• By promoting a quicker reaction rate and higher burning temperature that allows electrical energy savings and less fuel consumption

The use of alternative fuels contributes to a reduction in greenhouse gas emissions at two levels:

1) The first reduction occurs at the substitution level, where fossil fuels are replaced by alternative waste fuels with lower GHG emissions than traditional fuel sources; this results in a direct reduction in GHG emissions.

2)

Portland cement is the basic ingredient of concrete. Concrete is formed when portland cement creates a paste with water that binds with sand and rock to harden. Cement is manufactured through a closely controlled chemical combination of calcium, silicon, aluminum, iron and other ingredients. Common materials used to manufacture cement include limestone, shells, and chalk or marl combined with shale, clay, slate, blast furnace slag, silica sand, and iron ore. These ingredients, when heated at high temperatures form a rock-like substance that is ground into the fine powder that we commonly think of as cement.

Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-speciality grout. It was developed from other types of hydraulic lime in England in the mid 19th century and usually originates from limestone. It is a fine powder produced by heating limestone and clay minerals in a kiln to form clinker, grinding the clinker, and adding small amounts of other materials. Several types of Portland cement are available. The most common, called ordinary Portland cement (OPC), is grey; but white Portland cement is also available. Its name was given because its inventor lived near Portland

Portland cement is one of the principal ingredients used in concrete. Concrete is a mixture of two components: aggregates and paste. The paste, comprised of cement and water, binds the aggregates (usually sand and gravel or crushed stone) into a rocklike mass as the paste hardens. A chemical reaction between cement and water produces a hardened paste that binds the aggregates together to form strong, durable concrete.

Heating limestone (calcium carbonate) in a kiln at 1,450 °C (2,642 °F) causes a chemical transformation where calcium carbonate reacts with silica-bearing minerals to form calcium silicates. The resulting substance is called clinker, which is then ground with a small amount of gypsum into a powder to make ordinary Portland cement. The burning process uses energy from fossil fuels; the clinker accounts for about 70% of the CO2 emissions from making cement. To reduce these emissions, manufacturers are looking for alternative binding materials to replace some or all of Portland cement as well as alternative fuels to reduce the amount of heat needed for the burning process.

Some other types of cement include: fly ash-lime cement, slag-lime cement and sulfate resistant cements.

Portland cement is a basic ingredient of concrete, mortar and most non-specialty 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. Portland cement may be grey or white.

Portland cement manufacturing begins with mining and then grinding raw materials that include limestone and clay, to a fine powder, called raw meal, which is then heated to a sintering temperature as high as 1450 °C in a cement kiln. In this process, the chemical bonds of the raw materials are broken down and then are recombined into new compounds. The result is called clinker, which are typically 3 millimeters (0.12 in) in diameter.[5] The chemistry of this reaction is not completely understood, but the end products can be analyzed by X-ray diffraction and compared to known crystalline phases.[6]

The next step in the process is to grind the clinker with other additives (such as gypsum). A wide variety of additives have been used in an effort to reduce