DALMIA 43 GRADE
The 43 Grade OPC cement manufactured at Dalmia units possesses superior level of quality. Our test certificates (see test certificate section on site) of the product depicts vividly that the quality level of the 43 Grade OPC cement is far superseding the specified requirements of the product. Some of the salient features of the product are given below:-
1. Gigantic compressive strength for superior grade of concrete and for economizing the project:
Dalmia Cement manufacturing units are blessed with consistent quality of cement grade Lime stone, which makes it possible to go for the most stringent quality standards and hence the compressive strength obtained for Dalmia 43Gr.OPC is superior and at least 10 Mpa higher than the specified requirements of BIS standards for all ages viz 3 days, 7days and 28days. This offers mighty strength to the concrete structures with extreme degree of durability and enables higher grade of concrete with cement content lower than that specified for the grade. There is also a possibility of reducing the cement content for a given grade of concrete if the same can be replaced with fine mineral admixtures to economize your project.
Please find hereunder the compressive strength achieved by Dalmia OPC 43 Vs 53 grades.
2. Volume stability:
Volume stability is an important character of the cement that affects the durability. The volume stability of the cement is mainly influenced by two parameters viz. Free Lime and Magnesia. These ingredients, when present in cement, exhibit a strange phenomenon as explained below. While other components undergo normal hydration, they remain dormant in the beginning and goes for a late reaction which involves expansion after a period of 5-7 years, when the whole structure has totally hardened. The stress exerted by such expansion reaction leads to cracks and damage of the construction. BIS has rightly added a clause in the specification that such expansion determined through Le-chatelier tests should not exceed 10mm. You will be very happy to know that the Le-chatelier expansion for Dalmia 43 OPC is hardly 0.5 mm, which is the least among all brands available in the market.
Similarly Magnesia, another deleterious component responsible for late expansion is limited by BIS to 6% in ordinary cements, where as its presence in our intelligently designed 43 Grade OPC cement is hardly 1%. The extremely low % of magnesia makes the concrete totally safe against expansion. The autoclave expansion is another test specified by BIS to understand such expansion and the maximum limit for autoclave expansion is limited to 0.8% by BIS. But, Dalmia OPC 43 possesses a very low volume expansion of 0.08% autoclave expansion, depicting the extra-ordinary volume stability of this supreme product.
3. Corrosion Resistance:
Chloride is another deleterious content in ordinary cement that attacks the steel reinforcement of RCC. The chloride contained in ordinary cements are highly soluble and hence the corrosion reaction initiates even when the concrete is green. The corrosion reaction of steel takes place in several stages, finally leading to the formation of Hydrated ferric Oxide, which has 6 times higher volume than original steel, which results in de-lamination of concrete cover from the underside of the concrete RCC slab, exposing the reinforcements to further atmospheric attacks. To protect the construction and the customer happiness, BIS has restricted the presence of chloride in cement to 0.1%, whereas Dalmia OPC 43 is a special product, unique by itself, with only 0.008% of chloride in it making it thoroughly chloride resistant. Besides the chloride attack aggravates when the pH of concrete is lower. The Dalmia OPC 43 imparts very high pH to concrete, due to the presence of calcium oxide as high as 64%.
This is just a few of the unique properties that our cement possesses and many more are self explanatory in the attached Test Certificate.
4. Low heat of hydration which is comparable to LHPC;-
As you are aware, high heat of hydration of cement play havoc in concrete for massive pour. The heat liberated by a particular component in cement by name Celite (C3A) is 4 times higher as compared to any other component in cement. This particular component ( C3A) is very carefully and thought fully restricted to 6% in Dalmia 43 OPC, which earns this product the distinction of competing with the specification of Low heat Portland cement (IS 12600)
In addition there are other key parameters where we exceed expectation which imparts distinct advantage to the concrete.