Influence of lime, calcium silicate and portlandite on alkali activation of calcined common clays
Influence of lime, calcium silicate and portlandite on alkali activation of calcined common clays
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DOI：
10.1016/j.oceram.2021.100152
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发表时间：
2021-09-01
期刊：
影响因子：
--
通讯作者：
Dehn, Frank
中科院分区：
文献类型：
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作者：
Dathe, Felix;Strelnikova, Vera;Dehn, Frank
富含方解石的普通粘土的应用对碱激活粘合剂的形成具有显着影响。实验表明，通过煅烧过程可以很好地控制碳酸盐的分解，其中大部分分解和随后的CO2释放发生在750℃的煅烧温度以上。方解石的脱碳酸大部分可以与层状硅酸盐的脱羟基分开。根据粘土原料的成分，CaCO3 分解会导致形成石灰或其他富含钙的矿物质。对碱活化粘结剂的机械性能进行了研究，尽管粘土原料的层状硅酸盐含量极低且惰性矿物含量高，但砂浆的抗压强度仍可达 20 MPa 以上。煅烧粘土中存在足够量的石灰对于砂浆的后固化和抗碳化性能具有积极影响。
The application of calcite rich common clays has marked impact on the formation of alkali-activated binders. Experiments have shown that the carbonate decomposition can be well controlled via the calcination procedure, whereby the majority of the decomposition and the subsequent CO2 release occurs above the calcination tem-perature of 750 degrees C. The decarbonation of the calcite can mostly be separated from the dehydroxylation of the layered silicates. Depending on the composition of the raw clay material, the CaCO3 decomposition leads either to the formation of lime or other Ca rich minerals. The mechanical properties of the alkali-activated binders were investigated and despite the very low amounts of layered silicates of the clay raw materials and the high content of unreactive minerals, compressive strengths of above 20 MPa of the mortars could be obtained. The presence of lime in calcined clays up to an adequate amount has a positive effect on post-solidification and the carbonation resistance of the mortars.