The Portland Cement Conundrum: A blog all about the cement industry and its environmental impacts.
white portland cement
White Portland cement is the basic ingredient of concrete. Concrete is a combination of cement, water, and aggregates comprising rock and sand. The cement is the glue that holds or binds the mix together into a solid mass. White Portland cement is essentially the same as ordinary, gray Portland cement except in its physical appearance. Because it is white, it provides a cleaner finish when used for making architectural concrete as compared to gray Portland cement.
It is used for decorative purposes, such as in pathways, sidewalks, driveways, and patios. White Portland cement is also used in combination with other materials to produce concrete masonry units such as bricks and blocks. It can be used to make precast concrete products like window sills, lintels and ornamental architectural features such as columns and finials.
How do components of the hydraulic cement interact? What is the effect of one component on another component? How do they affect the performance of the concrete? What is the effect of different proportions of each component on the final product? What are the effects of different production processes on quality and long-term performance? How does quality affect behavior and durability and how can it be measured with different laboratories, methods and testing equipment?
I am currently writing a book on this topic. The title is: “The Portland Cement Conundrum: A blog all about the cement industry and its environmental impacts.” I hope to publish it in 2014. I hope my readers will give me their comments.
In this blog, I will discuss the environmental impact of Portland Cement. Portland Cement is a material used for construction across the globe. This cement has been around for over 150 years and is still widely used today. The only way to create this product is to release carbon dioxide into the atmosphere. This makes Portland Cement one of the most environmentally damaging materials out there.
In the United States alone, about 100 million tons of Portland Cement is produced per year. In order to produce one ton of this cement, about 1 ton of carbon dioxide is released into the atmosphere. The leading producer of Portland Cement in the US is Buzzi Unicem USA with a production rate of about 17 million tons per year.
Portland cement is not a brand name, but the generic term for the type of cement used in virtually all concrete, just as stainless is a type of steel and sterling a type of silver. Cement comprises from 10 to 15 percent of the concrete mix, by volume. Through a process called hydration, the cement and water harden and bind the aggregates into a rocklike mass. This hardening process continues for years, meaning that concrete gets stronger as it gets older.
Cement is manufactured by heating lime, silica, alumina, iron, and other materials at high temperature. The resulting substance is a marble-like ball called clinker that is ground, mixed with limestone and gypsum, and used to create concrete. The burning of concrete clinker is a key stage in the manufacturing process of Portland cement.
If you’ve ever visited an active construction site or seen a house being built from scratch you’ve probably noticed large piles of sand and gravel (aggregates) next to mounds of powdered cement. These are some of the main ingredients that go into creating Portland cement:
1. Calcium (from limestone)
2. Silicon (from sand or raw shale)
3. Aluminum (from clay, b
The Portland Cement Association’s Environmental Life Cycle Assessment of Concrete (EPD-Concrete) is a new industry standard that quantifies the environmental impacts of concrete and its ingredients. The report is the result of a multi-year effort by PCA and several leading experts to develop a more comprehensive framework for measuring environmental performance.
The EPD-Concrete framework expands on the concrete industry’s former data collection efforts, which focused solely on greenhouse gas emissions. The new framework addresses a wide range of environmental impacts including air quality, water quality, land use, resource depletion, and primary energy demand.
The EPD-Concrete report also introduces three new metrics for evaluating the environmental performance of concrete: Eco-efficiency Index, Environmental Footprint, and Environmental Impact Index. These metrics provide an easy way for all stakeholders in the construction industry to quickly compare concrete with other building materials.
The Chicago Chapter of the American Concrete Institute will host an official release event for the EPD-Concrete report on August 13th at 5:30 pm in downtown Chicago at the offices of Pepper Construction (1 East Wacker Drive). The event will include two presentations from PCA staff – one on the methodology behind the report and another on how to interpret its
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-specialty 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 2 to 3 percent of gypsum. 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 refers to its colour not its content. The colour of a cement results from the raw materials and production process used.
While no official definition exists for white Portland cement, the “Portland Cement Association” defines it as having less than 5% by mass of tricalcium aluminate (a compound with iron which gives gray clinker its color). Some manufacturers are even more stringent about their product’s color and limit tricalcium aluminate to 1% or less. Thus white cement cannot be made from just any raw material mixture. Special care must be taken when selecting raw materials to ensure a low iron content in the finished
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-specialty 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 2 to 3 percent of gypsum. Several types of Portland cement are available.
The name “Portland cement” is also recorded in a number of patent applications that were being made in England in the early 19th century by Joseph Aspdin. He claimed that it was produced from cementitious material which he had burned only with clay and shale. Aspdin’s son William improved the process by burning the mix at a higher temperature for a longer time. The product was given the name ‘Portland cement’ because it looked like Portland stone when it hardened.
The most common use for Portland cement is to make concrete. Concrete is a composite material made 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