Skočibušić Pejić Josipa, Bašić Alma-Dina, Grubor Martina, Serdar Marijana
Department of Materials, Faculty of Civil Engineering, University of Zagreb, Andrije Kačića Miošića 26, 10000 Zagreb, Croatia.
Materials (Basel). 2024 Jul 18;17(14):3551. doi: 10.3390/ma17143551.
The problem of loss of strength caused by the conversion reaction with calcium aluminate cements (CAC) is well known. It has been shown that the addition of ground granulated blast furnace slag (GGBS) to CAC inhibits the conversion process. Different slags can have a different chemical and mineralogical composition depending on their origin and production process, which can significantly influence their reactivity. This work investigated the extent to which the R test, developed for Portland cement and based on isothermal calorimetry and/or bound water, was used to predict the reactivity of ground granulated blast furnace slag in a CAC. Mortars and cement pastes with a 30% replacement of slag were tested to evaluate their compressive strength and microstructure. The results show that slags with higher reactivity due to their hydraulic properties lead to a lower compressive strength loss within the first 6 h, a higher strength loss after 24 h due to stratlingite formation and a lower strength loss after 28 days due to pozzolanic reaction and stratlingite formation. The results also confirm that the R test was used as a rapid method to predict the effects of slag on the compressive strength of CAC.
由铝酸钙水泥（CAC）的转化反应导致强度损失的问题是众所周知的。研究表明，向CAC中添加磨细粒化高炉矿渣（GGBS）可抑制转化过程。不同的矿渣根据其来源和生产工艺可能具有不同的化学和矿物组成，这会显著影响它们的反应活性。这项工作研究了为波特兰水泥开发的、基于等温量热法和/或结合水的R试验在多大程度上可用于预测磨细粒化高炉矿渣在CAC中的反应活性。对用30%矿渣替代的砂浆和水泥净浆进行了测试，以评估它们的抗压强度和微观结构。结果表明，由于其水化特性而具有较高反应活性的矿渣，在最初6小时内导致较低的抗压强度损失，24小时后由于硅钙石形成导致较高的强度损失，28天后由于火山灰反应和硅钙石形成导致较低的强度损失。结果还证实，R试验被用作一种快速方法来预测矿渣对CAC抗压强度的影响。
