Portland Cement Hardening Process: Hydraulic Cement Fact

Is Portland cement a hydraulic cement that hardens by chemically combining with water?

Select one: a. False b. True

Final answer:

Yes, Portland cement is a hydraulic cement that hardens by hydration.

Explanation: The statement, "Portland cement is hydraulic cement and it hardens by chemically combining with water (hydration)", is indeed true. Portland cement attains its strength through a series of chemical reactions in a process known as hydration.

When Portland cement is mixed with water, it forms compounds like calcium silicates and calcium hydroxide, aiding in hardening processes like plaster formation and sulfur dioxide removal. The second step of the hydration process is the formation of solid calcium hydroxide as the only product from the reaction of solid calcium oxide with liquid water.

Cement hydration contributes to the hardening of plaster containing slaked lime (Ca(OH)2 + CO2) and the removal of sulfur dioxide from the flue gas of power plants (CaO + SO2). These chemical reactions explain why Portland cement hardens when mixed with water.

Portland cement is an essential component in construction and engineering projects due to its ability to form strong and durable structures. Understanding the hydration process of Portland cement is crucial for ensuring the quality and longevity of concrete structures.