硬化砂浆中水泥含量试验制样方法探讨

Discussion about sample processing methods of cement content in hardened mortars

为探索处理硬化砂浆试样的方法,使水泥含量测定结果更接近真实值,首先成型不同粉煤灰掺量的砂浆试样,在砂浆试样标准养护到一定龄期后,基于硬化胶凝材料中结合水的损失过程,利用Ca O测定法研究不同的试样处理方法对硬化砂浆中水泥含量测定结果的影响,得到处理硬化砂浆试样的方法:即无水乙醇终止水化后,60℃鼓风烘干,然后以10℃/min的速度由室温升到(520±10)℃,保持1 h,并且通过实验证明结合水含量是影响硬化砂浆中水泥含量测定结果的关键因素之一。采用该方法处理后,不同龄期相同胶凝材料含量和同一龄期不同粉煤灰掺量硬化砂浆中水泥含量测定结果的相对误差都在±5%以内。

In order to get the result that is close to the real value of cement content in hardened mortars, different samples with varied content of fly ash were prepared. After the mortar samples were cured for a certain age in a standard environment, based on the loss of bound water in hardened cementitious materials, the effect of different sample processing methods on cement content in hardened mortars was investigated via CaO measurements. The authors found an ideal processing method, that is after stopping hydration by anhydrous ethanol, sample was blast dried at 60 ℃ , then temperature was increased from room temperature to （520 ±10）℃ in the rate of 10 ℃/min,and then maintaining for lh. The bound water content is one of the key factors to the measurement results of cement content in hardened mortars. By using this processing method, the relative deviation of cement content of hardened mortars with different ages and fly ash content is set within ± 5 %.