基于部分煅烧水菱镁矿-煅烧黏土胶凝材料的水化特性及机理

Hydration Characteristics and Mechanism of Partially Calcined Hydromagnesite-Calcined Clay Cementitious Material

利用一种新的部分煅烧策略,将水菱镁矿在低温下保温较短时间使其部分分解为氧化镁,并探究其与煅烧黏土复合制备胶凝材料的潜力。研究表明:部分煅烧水菱镁矿中除了MgO外,还含有未分解的无定形碳酸镁,其存在能够提高Mg O水化生成Mg(OH)_(2)的速率,显著提高胶凝材料的早期力学性能,但后期强度发展速率下降;与完全煅烧水菱镁矿相比,无定形碳酸镁含量占总质量的3.0%时,1d强度提高了167%。部分煅烧策略不仅能够有效降低碳排放和能耗,还能提高胶凝材料的早期强度。

Using a new partial calcination strategy,which partially decomposes hydromagnesite into magnesium oxide at a lower temperature for a short time.It also explores the potential of preparing cementitious materials by mixing them with calcined clay.The research showed that in addition to MgO,partially calcined hydromagnesite also contained undissolved amorphous magnesium carbonate,which could enhance the rate of MgO hydrated into Mg(OH)_(2) and significantly improved the early mechanical properties of the cementitious material,but the development rate of strength in the later stage decreased.Compared with completely calcined hydromagnesite,while the content of amorphous magnesium carbonate accounts for 3.0%of the total mass,the 1 day strength was increased by 167%.Partial calcination strategies can effectively reduce carbon emissions and improve the early strength of cementitious materials.