Hydration Kinetics and The Compressive Strength of Cementitious Systems Containing Pumice and Metakaolin


İbrahim A. E. , Yorulmaz H., Uzal B.

II. International Congress on Art and Design Research , Kayseri, Turkey, 20 - 21 June 2022, pp.1027-1035

  • Publication Type: Conference Paper / Full Text
  • City: Kayseri
  • Country: Turkey
  • Page Numbers: pp.1027-1035

Abstract

During the production of one ton of Portland cement, approximately one ton of carbon dioxide is emitted to the environment. It is known that the cement industry is responsible for nearly 8% of the total CO2 emissions in the world. Today, where sustainability is becoming more and more important, this rate is remarkably high. One of the alternative ways to reduce this rate is to partially replace the Portland cement with mineral additives. For this purpose, cementitious systems have been formed by partially replacing Portland cement with 5% and 10% metakaolin by weight; and with 15%, 20%, 30% and 35% of pumice powder. By adding different amounts of superplasticizer to all mixtures, it was ensured that the flow values were similar (±5%) to the flow value of the control sample without replacement. Isothermal calorimetry tests were conducted to observe the effect of metakaolin and pumice on the hydration kinetics. In addition, the effects of mineral additives on the compressive strength of the cementitious mortars at 7 days and 28 days of age were investigated. In the isothermal calorimetry results, the second peak of heat evolution curve became more evident with metakaolin replacement when compared to cement pastes containing pumice. According to the results obtained from the compressive strength test, it was observed that the strength of the sample with 20% pumice was comparable to the strength of the control sample at 7 days. At 28 days of age, the compressive strength of ternary cementitious systems prepared with 15% pumice and 5% metakaolin replacement were comparable to the control sample. Moreover, the addition of 15% and 20% pumice to the system containing 5% metakaolin at 7 days and 28 days showed similar strength values.