Portland White Cement is similar to grey portland cement except for its higher degree of whiteness and fineness.
Portland cement white is expensive as compared to OPC owing to its manufacturing method and specific requirements for raw materials.
The commercial name of white ordinary portland cement is Snowcrete.
What is White Portland Cement?
White Portland cement is a specialized type of cement that is formulated to create a bright white
color after curing.
Commonly, it is used in applications where a white or light-colored appearance is desired.
Examples of such are architectural and decorative projects.
White Portland Cement Composition
White portland cement shares similar composition to ordinary portland cement, but with some
modifications to achieve its distinctive white color.
The primary components of white Portland cement composition include:
- Clinker
- Gypsum
- White pigments
As it can be seen the main difference is the white pigments, which are the reason for the
characteristic color of the white cement. These pigments help reflect light and contribute to the
cement’s brightness.
It is worth noting that Different manufacturers may have their own unique formulations, but the
general composition follows the mentioned components.
White Cement Manufacturing Process
White cement is produced on pulverization of white portland cement clinkers. Clinker obtains a white color when the total iron content is less than to 0.5 % and the iron is reduced to ferrous iron.
Raw Materials
Iron oxide contributes to the grey color in OPC. There are other constituents too, which impart color in cement.
Constituents responsible for color in portland cement are listed below in decreasing order:
- Chromium (Cr)
- Manganese (Mn)
- Iron (Fe)
- Copper (Cu)
- Vanadium (V)
- Nickel (Ni)
- Titanium (Ti)
All the above constituents are added in minimum possible requirements. Other constituents do not pose significant problems for the white cement.
Limitations of the three prominent color-providing oxides in White Cement Clinker:
| Cr2O3 | Less than 0.003 % |
| Mn2O3 | Less than 0.03 % |
| Fe2O3 | Less than 0.35 % |
Iron and manganese occur together in nature. Hence, if material with low iron is taken, then manganese content will also be less.
Impurities in Materials obtained from Quarry:
Portland cement is manufactured from cheaper materials obtained from quarry. These materials contain impurities as chromium, manganese, ad iron oxides commonly.
Chromium may be introduced in the white cement through other sources too. During grinding, it may be introduced in the cement mix from the chrome steel used in the grinders.
High sand content makes increases the abrasiveness and is ground separately in ceramic grinding equipment.
| Constituent | Iron Oxide Content Present as Impurity | Iron Oxide Limit for WOPC |
| Limestone | 0.3-1 % Fe2O3 | Less than 0.1 % |
| Typical Clay | 5-15 % Fe2O3 | Less than 0.5 % |
Instead of iron oxide, sodium alumina fluoride is added as catalyst during burning.
Usage of Kaolin:
Owing to high iron oxide content in typical conventional clay, kaolin is used in white cement. Now, kaolin has very low silica content as compared to the conventional clay. Therefore, amount of sand is increased in white cement to compensate the silica amount.
Off-white clinker
For off-white clinker, calculated amount of ferrous oxide is added increasing it to 0.6-0.8 %.
Ash helps the clinkers in the following way in off-white cement-
- Finer than ground material, hence helps in reaction
- Can reach higher temperatures
- Gets molten in flame
- C3A content is also added in calculated amount as 7-9 %.
Blended cement is mixed with granulated blast furnace slag cement to make it sulphate resisting or low heat cement.
Kiln Operation
Raw materials described above are mixed in rotary kiln at 1600 ° C.
As temperature requirements increases, more fuel is consumed. The fuel consumption is increased by 20-25 %. While kiln output decreases by 20-50 %. The reason is that the final reaction of conversion of dicalcium silicate to tricalcium silicate is slowed down.
Off white Clinkers
Using coal firing during fine grinding can increase the output lowering cost.
Grinding
Gypsum is added to control the setting of cement as in case with OPC.
Titanium dioxide may also be added to increase the reflectance of white cement.
Characteristics of White Portland Cement
The physical and chemical characteristics of white portland cement are given below:
Physical Characteristics of White Portland Cement
Physical requirements of white cement should be conferred to as mentioned in IS: 269 – 1989 for Ordinary Portland Cement of 33-grade.
Compressive Strength Criterion: The compressive strength of white cement shall not be less than 90 % of that mentioned for 33-grade OPC.
Chemical Characteristics of White Portland Cement
| Characteristic | Requirement |
| Lime saturation factor Maximum Minimum | 1.09 0.66 |
| Iron Oxide by mass | ≯ 1 % |
| Insoluble Residue by mass | ≯ 2 % |
| Magnesia by mass | ≯ 6 % |
| Loss on ignition | NIL |
| Total Sulphur Content as sulphuric anhydride by mass When C3A ≤ 7 When C3A > 7 | 2.75 3.0 |
| Calculation of C3A Content: C3A = 2.65 (Al2O3) – 1.69 (Fe2O3) | |
Degree of Whiteness
Degree of whiteness is measured by the reflectance of neat cement ring as mentioned in IS: 8042 – 1989.
Degree of whiteness measured by ISI scale ≮ 70 %
Hunters scale
Whiteness can also be measured by Hunters Scale. The value is generally 90 %.
Properties of White Portland Cement
White cement has same properties as that of OPC. However, some of the differences are-
- Loss on ignition is nil.
- Compressive strength is 90 % of that of OPC.
- Additionally, the low alkali content in white cement makes them non-staining.
IS Specification for White Portland Cement
The specifications for physical and chemical requirements for white cement are mentioned above.
Minimum degree of whiteness is also specified as 70 %.
Storage, Sampling, Tests, and Rejection
The requirements for storage of cement should conferred to that of ordinary portland cement.
Cement bags should be kept away from wall and above ground level to prevent moisture contact. To know the precautions while storing cement, Refer Storage of Cement.
Delivery
White cement should be packed bags and delivered to site.
Requirement for White Cement Bags can be found HERE.
Advantages of White Portland Cement
- It provides more thermal insulation than any other type of cement
- It is a good reflector of light, hence saves energy
- Its products can be recycled and reused after the end of useful life
- It can be used as wall putty to fill uneven surfaces before applying paints (grey cement may leave undesirable color spoiling the aesthetics)
- It can be used for whitewashing along with lime; it increases the adhesive properties of lime
- It is a strong water proofing agent, hence need for waterproof coating is eliminated
- It has greater ability to withstand higher temperature
Disadvantages of White Portland Cement
- It is expensive than OPC
- Its strength is less comparatively
White Cement Uses
- Floor finish
- Plasterwork
- Ornamental work
- Production of white concrete
- Production of colored cement
- Production of precast members
- Skirting
- Terrazzo flooring
- Stucco plaster
Applications of White Portland Cement
- White cement can be used to produce white concrete by using white aggregates
- Inorganic pigments can be added to white cement to produce brightly colored concrete. Concrete produced keeping grey cement as base gives dull colors.
Colors like bright red, yellow, and green can be produced with white cement as base. Production of blue cement increases the cost.
| Constituent | Color |
|---|---|
| Iron Oxide | Brown, red, yellow |
| Chromium Oxide | Green |
| Cobalt Oxide | Blue |
| Manganese Oxide | Black, brown |
Pigments are added during mixing to produce colored cement.
- White cement with high early strength can also be produced. It will then confer to the specifications of ASTM C 150 Type III.
This cement is very useful for precast concrete sections as early strength gain increases the production
- Highway meridians on roads can be differentiated by using white cement. Using white cement increases the visibility, which is essential on road transport.
- It can be used for fixing the marble tiles in flooring. It can also be used for sheathing of walls, floors.
- It can also be used for skirting of walls. The addition of white cement to lime retains the white color. At the same time, it also provides adhesive characteristics to lime increasing the longevity of plaster.
Portland Cement and White Cement
The differences between white cement and portland cement as well as coloured cement are
tabulated below-
Portland Cement vs White Cement
| Portland Cement | White Cement |
| It is grey in color | It is white in color |
| Its compressive strength is higher | Its compressive strength is comparatively lower |
| Its particle size is less fine | Its particle size is more fine |
| Its specific surface is less | Its specific surface is more comparatively |
| Alkali content is comparatively more | Alkali content is less |
| Iron oxide is present | Iron oxide needs to be restricted below 1 % |
| Maximum lime saturation factor is 1.02 % | Maximum lime saturation factor is 1.02 % |
| It can be used for general construction work | It can be used for decorative and ornamental purpose |
| It is less costly | It is expensive |
White and Colored Portland Cement
| White Cement | Colored Cement |
| It is white in color | It can be of any color like red, yellow, green, brown, blue, etc |
| It can be used as base for colored cement | It uses grey/white cement as base |
| Pigments are not added | Coloring pigments are added |
| Comparatively less expensive | More expensive than white cement |
White Portland Cement in India
The raw materials for white cement, especially limestone is available only around Jodhpur in Rajasthan. Limestone should be composed of a minimum 96 % calcium carbonate.
Because of this reason, two famous brands producing white cement are located near Jaipur. These are Birla White and J. K. Cements.
Birla White Portland Cement
The physical and chemical characteristics of white cement produced by Birla White are compared below:
| Characteristics | Birla White | IS: 8042 – 1989 |
| Physical Characteristics | ||
| Degree of whiteness (min) | ||
| ISI | 88 % | 70 % |
| Hunter Scale | 91 | |
| Fineness (min) | ||
| Specific surface | 450 m2/kg | 225 m2/kg |
| Setting time | ||
| IST min | 80 min | 30 min |
| FST max | 120 min | 600 min |
| Compressive strength (min) | ||
| 3 days | 45 MPa | 14.4 MPa |
| 7 days | 55 MPa | 19.8 MPa |
| 28 days | 67 MPa | 29.7 MPa |
| Soundness (max) | ||
| Lechateliers method | 1 mm | 10 mm |
| Autoclave expansion | Negligible | 0.8 % |
| Retention on 63 micron IS sieve (max) | 1 % | – |
| Chemical Characteristics | ||
| Insoluble residue (max) | 0.6 % | 2 % |
| Iron oxide (max) | 0.2 % | 1 % |
| Magnesia (max) | 0.8 % | 6 % |
| Sulphur trioxide (max) | 2.9 % | 3 % |
| Alumina/Iron oxide (min) | 9 % | 0.66 % |
| Lime saturation factor | 0.9 % | 0.66-1.09 % |
| Loss on ignition (max) | < 3 % | Nil |
White Portland Cement Price
White portland cement cost is much more than that of OPC. White cement costs about 4 times the price of ordinary portland cement.
The cost increase is because about 40 % more energy is consumed in the manufacture of white cement. Besides this, precautions are to be taken to ensure that the cement is not contaminated during the time.
Key Take Away
White Portland Cement has almost same properties as that of the ordinary portland cement, excluding color and fineness.
Limiting iron content in its manufacturing and using impurity-free limestone can produce white cement. Conventional clay should be substituted by kaolin to reduce iron content.
Physical characteristics of white cement are almost same as OPC. However, its specific surface is more and compressive strength is 90 % of that of 33-grade OPC. Loss on ignition should be nil.
Degree of whiteness should not be less than 70 %, as per IS: 8042. Reflectance value more than 85 % is recommended.
White cement can be used for flooring, ornamental works, plastering, precast members, producing white concrete, skirting, etc. It is also used in the manufacture of colored cement as base.
The cost of white cement is about 4 times the cost of OPC.
FAQ
What is white cement used for?
White cement is used for-
- Floor finish
- Plasterwork
- Ornamental work
- Production of white concrete
- Production of coloured cement
- Production of precast members
- Skirting
- Terrazzo flooring
- Stucco plaster
Can I use white cement instead of cement?
Yes, you can use white cement instead of ordinary cement. White cement has almost all
constituents similar to OPC, except for the ones responsible for colour like iron oxide. The
cement compounds like tricalcium silicate, bicalcium silicate, tricalcium aluminate, and
tetracalcium aluminoferrite. Hence, other properties are the same except for compressive
strength. It is 90 % to that of 33-grade OPC.
Using white cement is expensive. It is about four times that of the ordinary portland cement.