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Claude Green
CAD technician
Asked a question 2 years ago

Why strength of white cement is less than OPC cement?

Why strength of white cement is less than OPC cement?

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Ross Kim
Geotechnical engineer

Production of white concrete with a compressive strength between 25 and 50 Mpa is possible by using white cement. It was also found out in study that white concrete had higher compressive strength than normal gray concrete. The strength in opc cement comes from calcium aluminate present in it. In another hand, for achieving white color in white cement limestone, chalk, and clay are mixed due to which it gets expand and leads to lower strength.

OPC stands for ‘ordinary portland cement’ mainly used for high rise building construction which took the lowest time to set and harden. OPC is manufactured to powdered form by mixing limestone and other raw materials containing argillaceous and calcareous components and gypsum.

White cement is having its commercial name as ‘snowcrete’ which differs from OPC in mainly its white color. It consists of very low iron oxides and manganese oxides that influence the undertone of snowcrete. Generally, china clay is used with chalk or limestone in its manufacture.

The above mentioned white color giving materials cause the snowcrete to expand and this expansion leads to its lesser compressive strength compared to OPC.

The production of white cement requires 40% more energy than OPC and this more heat requirement for burning of raw materials in snowcrete and more energy consumption also leads to lesser strength.

Fineness of white cement is 395m2/kg which is also higher than OPC.

Due to the white color of snowcrete it is used to architectural beauty, decorative purposes, ornamental purposes, inroads due to its reflectiveness while grey cement is widely used for construction purposes.

Nowadays researches are undergone and the strength of white cement even risen much and experimentally it is shown that white cement has its strength is almost two-third of that of OPC.

The process of manufacturing white cement is different from that of the OPC. To achieve the white color, limestone, chalk, and clay are the primary materials, and they cause the cement to expand. This expansion leads to lower strength.

However, this shortcoming has been overcome by many cement manufacturers, and now the white cements have equal strength to that of the OPC cement.