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Portland Cement 42.5 N/R

 

 




AGT specializes in buying and selling Portland Cement. We have built unique relationships in the cement industry and we are able to offer Ordinary Portland Cement or N/R at low prices from large cement mills or through cement allocation mandates. Our cement is manufactured globally and can meet US, British, SABS and other specifications. If you are trying to import or export cement we can help.

Who are we?
AGT is comprised of experienced and well connected mandates around the world. We operate out of 4 offices in Australia, Vietnam, Pakistan and China and work around the clock to find you the best prices from well established mills to satisfy even the most demanding requirements.

Why are we different?
We do not accept everyone as a client. We only work with Buyers who present Bank Comfort Letters or provide Bank authorization to probe with their ICPO's. If you do not have a BCL or won't allow permission to probe - please do not contact us as we will not believe you are a serious Buyer. We do not work with just any Seller Mandate - we only work with those Mandates who can offer great pricing, great availability and great service - and ones that perform well. We are not for everyone and we don't try to be - we are for serious buyers who desire professional service quickly and want to close a deal fast.

How do we do what we do?
We are able to offer you the best prices and service because we order in volume. Because we are able to place large orders we are able to obtain preferential pricing which enables our clients greater buying power.

Why is our conversion rate so high?
We are selective about the deals we take, we only deal with financially capable Buyers, and our mandates perform to the letter - happy Buyers make great repeat customers - that's our specialty - keeping buyers happy and worry free.

Cement History
The concept of cement has been with humanity virtually since the first attempts at construction began over 600,000 years ago when man moved out from the caves and began to construct his own housing from wood and wattle, and then later on, from mud bricks.

Wood and wattle houses (also known as post houses, because of the wooden posts which were often erected to give them structural integrity) were made by weaving wattle and wood together, and then daubing them with a mixture of materials containing cow dung, lime, and mud. This daub sealed the houses as it dried, due to the reaction of certain chemicals present in the cow dung with the lime in the mixture. The substance produced by this reaction made a strong, solid coating which protected the inhabitants of the building from the elements.

The bricks of mud brick homes were also joined together with a kind of primitive cement, a clay based slurry that dried hard and kept the bricks in place. Both so called ‘cow dung’ and mud brick techniques are still used by some tribal populations when building homes to this very day, and evidence of the relative efficacy of these techniques can be observed in many small tribal villages in Africa.

In many parts of the world however, as mankind evolved from primitive societies towards more technologically advanced ones, better techniques were evolved for the making of bricks. Fired bricks, heat treated in kilns were used in in construction applications in Egyptian and Mesopotamian societies, and as the buildings built by these, and other advanced societies, became larger and more complicated, a need arose for a better kind of binding agent with which to join the bricks together. Various cultures and societies began to experiment with different types of cement like substances to be used as mortar in their buildings. Lime became a popular choice throughout much of the world as an additive which added strength and durability to existing types of cements and mortars. The Egyptians also used gypsum, which is still used in modern cement as an additive which controls how quickly cement sets.

Modern Cement<br /> Modern cement was not invented until the Industrial Revolution which took place in Europe in the late 18th century. Technology was booming during this time, and the need for new and better materials with which to build structures was high. Modern cement was developed in response for a need for stronger concretes, and for cements which could be used in structures which were commonly exposed to water, such as those near the sea, and those in rainy climates.

Prior to this time, stone had been the primary building material, but supplies of stone suitable for building were beginning to run low, and prices were higher than ever before. Some ingenious builders and designers began to build buildings from brick instead, and finished them with a type of stucco that made them appear to be made out of stone. Because these large British buildings had to be completed on strict schedules, there was no time to wait around for weeks on end for cement to dry. In response to this need, a range of quick drying cements were developed.

One of the most popular early quick drying cements was known as ‘Roman’ Cement. It was developed in the 1780’s by a man named James Parker, and was manufactured by burning a specific type of clay deposit known as septaria, a substance which contains both clay and chalk, and grinding the post firing material down into a very fine powder. When combined with sand this cement made for a very quick setting mortar which could dry in just 15 minutes.

The next major development in cement technology was a strong type of hydraulic cement. Hydraulic cement is a type of cement that needs to be mixed with water in order for it to set, and is not soluble in water once it has set and dried.

Prior to the 1820’s, most all cements had been non hydraulic in nature, meaning that they were dry mixtures which had to remain dry in order to develop the necessary strength which was needed for construction applications. This was obviously a problem in many respects, especially in construction projects which involved a great deal of water. The first step towards truly effective hydraulic cements was taken by an English engineer called John Smeaton in 1755 , who was building a lighthouse, and during his investigations into possible construction materials which might be suitable for the building of a lighthouse, discovered that the more clay that was present in the cement, the more hydraulic it was.

For the next seventy years or so, various people worked on the problem of creating a strong cement which could withstand the rigors of being rained on, or washed up against by waves without dissolving away leaving buildings which used it nothing more than untidy piles of bricks.

Portland cement, a hydraulic cement which is still in popular use today was invented by Joseph Aspdin who patented the product in 1824, however it was his son, William Aspdin who developed the strength and durability of Portland cement by adding a compound called ‘alite’ to it, which is still used to strengthen cement today.

William had a difficult time at first convincing people of the usefulness of his product, as it contained much more lime than the original Portland cement, and so needed to be fired at much higher temperatures. Also, due to its hardness, the resulting clinker developed during the firing process caused problems during grinding because it would wear down the millstones much more quickly than other types of cement.

The saving grace of Portland cement was the fact that the end product was a slow setting, high strength cement which could be mixed with concrete to create structures which developed strength quickly, unlike earlier cements which could take weeks to develop enough strength for timber framing to be able to be removed.

Portland cement is now the most popularly used type of cement in the world, although since the 19th century, many different types of cement have been developed for use in different kinds of applications. A few of these cements include expansive cements, which do not shrink during drying like typical hydraulic cements, colored cements, for decorative uses, and masonry cements, which have been developed for used solely in masonry applications and which are not suitable for use in concrete. Cement continues to evolve, though admittedly at a much slower pace than it did during the boom years of the Industrial revolution. Necessity will always be the mother of invention, and as long as we encounter new needs which are unfulfilled by cement products currently available on the market, it is certain that new types of cement will be developed.