Refer to the product literature of Emami Cement.
Yes, Emami Cement can very well be used in underwater works.
Pre addition of water proofing chemicals in cement could be detrimental, hence we do not add any water proofing compound to cement. Whereas, we manufacture cement in such a way, which will render structure water resistance by continuous pore refinement in concrete mass. However, we don’t object if any body uses water proofing compound with Emami cement under strict supervision and control while making concretes of any grade.
Refer IS 456 : 2000.
It depends upon the type of work, like
For mortar / plaster, the quantity of water will be close to 18 - 20 liter / 50 kg bag of cement or until the mix becomes cohesive. For concrete, the quantity of water will be close to 28 to 30 liter / 50 kg bag of cement or until the mix becomes cohesive.
(Please note that the above water quantity is tentative in nature, which needs to be adjusted in line with the dryness or wetness of aggregates available at site.)
Emami Cement is suitable for all weather conditions.
Mostly found in PSC base construction, which is due to formation of chromium dioxide (green in color) when wet. This patch disappears once the surface gets dry.
The soluble salt within the brick, comes out on the surface along with the out ward water flow. The salts accumulates mostly along the line of joint, because wet mortar supplies water to soluble salt to get de solved, which on drying comes out along the line of joint.
Cement shrinks during the process of drying, causing hair cracks on the exposed surface.
Emami Cement is manufactured by burning a mixture of limestone and clay at high temperatures in a kiln, and then finely grinding the resulting clinker along with gypsum producing Portland Cement (OPC). This Portland cement is composed of calcium silicates, aluminates and aluminoferrite in a Balanced Form.
When the same clinker is ground with small quantities of gypsum along with Pozzolans (Fly ash or Slag) to a fine powder, it is called as Blended or Composite Cements namely Portland Pozzolana Cement (PPC) and Portland Slag Cement (PSC).
When mixed with water, sand and stone, it combines slowly with the water to form a hard mass called Concrete.
Cement is a hygroscopic material meaning that it absorbs moisture from its surroundings. In presence of moisture it undergoes chemical reaction termed as hydration. Therefore cement remains in good condition as long as it does not come in contact with moisture. However, if the cement is more than three months old then it should be tested for its strength before being taken into use.
The shelf life of cement entirely depends upon the type of packaging and its storing conditions. Emami cement can be stored in godown for maximum upto three months, though we assure the freshness of cement even after 3 months, we insist to check the strength of cement prior to its usage.
When water is mixed with cement, the paste so formed remains pliable and plastic for a short time. During this period it is possible to disturb the paste and remit it without any deleterious effects. As the reaction between water and cement continues, the paste loses its plasticity. This early period in the hardening of cement is referred to as 'setting' of cement.
All the available cement belongs to grey cement category. So, color is not at all determinant for cement quality. Normally, cement containing un burnt carbon, gives black appearance, though un burnt carbon having it’s own ill effect on concrete durability.
Slag is a non-metallic product consisting essentially of glass containing silicates, alumino-silicates of lime and other bases and is obtained as a by-product in the manufacture of pig iron in a blast furnace or electric furnace. Granulated slag is used in the manufacture of Portland Slag Cement (PSC).
PSC is made by intergrinding clinker, granulated blast furnace slag and gypsum, or by blending ground slag with Portland cement.
PSC can be used for all plain and reinforced concrete constructions, mass concreting structures such as dams, reservoirs, swimming pools, river embankments, bridge piers, etc. It is used with advantage where low heat of hydration and resistance to alkali-silica reaction are desired, for structures in aggressive environments where chemical and mildly acidic waters are encountered (where the use of OPC is not recommended), for marine constructions, dykes, wharves, etc where sulphatic water is encountered.
Yes it is very much workable with crusher sand. We recommend lowering the sand proportion by 1 in above ratios, as crusher sand has more specific surface area in most of the cases.