Critical aspects in the handling of reactive silica in cementitious materials: Effectiveness of rice husk ash vs nano-silica in mortar dosage
Critical aspects in the handling of reactive silica in cementitious materials: Effectiveness of rice husk ash vs nano-silica in mortar dosage
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DOI：
10.1016/j.conbuildmat.2019.07.023
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发表时间：
2019-10
影响因子：
7.4
通讯作者：
M. Torres‐Carrasco;J. Reinosa;M. de la Rubia;E. Reyes;F. Alonso Peralta;Carlos Segovia Fernández
中科院分区：
文献类型：
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作者：
M. Torres‐Carrasco;J. Reinosa;M. de la Rubia;E. Reyes;F. Alonso Peralta;Carlos Segovia Fernández
纳米二氧化硅的加入改善了砂浆的机械性能和耐久性。然而，纳米材料处理需要使用职业风险预防措施作为工人的个人防护设备。此外，纳米材料的高度团聚在预期的砂浆性能中产生不确定性。将稻壳灰作为水泥组合物中反应性二氧化硅的来源与纳米二氧化硅进行比较。稻壳灰的使用提供了与其他商业纳米二氧化硅类似的物理化学胶结材料，在组合物期间提供了相关差异。在处理剂量期间，发现二氧化硅纳米颗粒的挥发性接近50重量%。因此，稻壳灰呈现出降低的挥发性，约12%wt，并且其允许确保高含量和足够的可加工性。掺入稻壳灰的砂浆具有较高的抗压强度和电阻率，同时具有较低的孔隙率。为此，在水泥组合物中使用稻壳灰作为比纳米二氧化硅更安全的替代材料是可行的。此外，由于稻壳灰来自农业废弃物资源，因此将其用作二次原料将通过减少工程纳米材料的消耗来促进经济的循环。
Nano-silica addition improves mechanical and durability behavior in mortars. However, nanomaterial handling requires use of occupational risk prevention measures as Individual Protection Equipment for the workers. Moreover, the high agglomeration of nanomaterials produces uncertainty in the expected mortar performance. Rice husk ash as a source of reactive silica in cement compositions is compared with nano-silica. The use of rice husk ash provides similar physical-chemical cementitious materials than other commercial nano-silica providing relevant differences during the composition. Near 50% wt of volatility is found for the silica nanoparticles during the handling dosage. Thus, the rice husk ash presents a reduced volatility, ∼12% wt and it allows ensuring high content with adequate workability. Mortars with addition of rice husk ash reach higher compressive strength and resistivity in correlation with lower porosity. For that, the use of rice husk ash is viable as safer alternative material than nano-silica in the cementitious compositions. In addition, as the rice husk ash comes from agricultural waste resources their use as secondary raw material will contributes to circularity in the economy by reducing engineered nanomaterials consumption.