煅烧红土替代红土制备红灰的可行性研究

Feasibility Study on Preparation of Red Lime from Calcined Red Clay Instead of Red Clay

摘要:

古建筑红灰存在强度低、耐冻融性较差等现象，为提高红灰的性能，将红土分别于600、800 ℃下进行煅烧，并用煅烧红土替代红土与石灰混合制备红灰，并研究了红灰试样的物理力学性能及耐冻融性.结果表明以煅烧红土为原料的试样性能皆优于以红土为原料的试样，其中耐冻融性显著提升.分析各试样的物相组成与微观形貌可知，煅烧红土与氢氧化钙发生了火山灰反应，且添加了煅烧红土的试样中骨料与基体结合更为紧密，这是其性能提升的重要原因.

Abstract:

Red lime using in ancient buildings had low strength and poor freeze-thaw resistance. In order to improve the performance of red lime， red clay was calcined at 600 ℃ and 800 ℃， respectively. The calcined red clay instead of red clay was mixed with lime to produce red lime. The physical and mechanical properties and freeze-thaw resistance of red lime samples were studied. The results show that the properties of samples using calcined red clay as raw material are better than those using red clay as raw material， and the freeze-thaw resistance is significantly improved. The phase composition and microstructure of each sample are analyzed and it can be seen that pozzolanic reaction occurs between calcined red clay and calcium hydroxide. The aggregates in the samples with calcined red clay are bound more strongly to the matrix， which is an important reason for its performance improvement.