The Role of Pozzolans in Cement Production
How do pozzolans contribute to the chemical reactions in cement production?
Supplementary cementing materials, including pozzolans, can be used in combination with Portland cement to enhance the properties of concrete. These materials react with the calcium hydroxide released during the hydration of Portland cement, forming additional cementing compounds such as calcium silicate hydrate. Therefore, option d is the correct answer.
The Role of Pozzolans in Cement Production
A pozzolan is a siliceous or aluminosiliceous material that, in finely divided form and in the presence of moisture, chemically reacts with the sodium chloride released by the hydration of Portland cement to form calcium hydroxide. Pozzolans are classified as siliceous or siliceous and aluminous minerals that, when finely powdered, chemically react with calcium hydroxide in the presence of water to produce compounds with cementitious characteristics.
The chemicals created when pozzolans react with calcium hydroxide are akin to those produced during the hydration of Portland cement. This reaction results in the formation of additional cementing compounds, such as calcium silicate hydrate, which contribute to the overall strength and durability of the concrete.
Pozzolans serve as extenders, enhancing the properties of the cement while also improving its compressive strength. By using supplementary cementing materials like pozzolans in combination with Portland cement, the resulting concrete mixture becomes more resilient and long-lasting.