三乙醇胺助磨剂对蔗渣灰颗粒特性及蔗渣灰砂浆性能的影响

为研究不同质量掺量三乙醇胺(TEA)作助磨剂对蔗渣灰颗粒特性的影响,通过方孔筛筛余量、粒径分布、比表面积和颗粒形貌测试对蔗渣灰颗粒特性进行表征,研究蔗渣灰颗粒特性对蔗渣灰砂浆强度及抗氯盐侵蚀性的影响。结果表明,TEA可优化蔗渣灰颗粒粒径分布,在最佳质量掺量0.08%条件下,＜32 μm的颗粒占比增加8.2个百分点,比表面积可提升至5.503 5 m²/g,颗粒形貌更趋于圆球状。同时,蔗渣灰砂浆的强度和抗氯盐侵蚀性能随着TEA掺量的增加呈现先增后降的变化规律,TEA在0.08%(质量分数)最佳掺量时,蔗渣灰砂浆的抗压强度相比于普通水泥砂浆提升19.88%,氯离子扩散系数下降79.63%。通过X射线衍射和压汞孔分析测试揭示了蔗渣灰颗粒特性对蔗渣灰砂浆性能的影响机理,研究表明:经过TEA助磨剂优化后的蔗渣灰火山灰反应活性得到提升,蔗渣灰砂浆基体中生成更多水化产物,提高了密实度;优化后的蔗渣灰颗粒充分发挥了填充效应,降低蔗渣灰砂浆的孔隙率,提高了蔗渣灰砂浆的强度和抗氯盐侵蚀性能。

Effect of Triethanolamine Grinding Aid on Bagasse Ash Particle Characteristics and Properties of Bagasse Ash Mortar

In order to study the effects of different mass dosage of triethanolamine (TEA) as grinding aid on the particle properties of bagasse ash, the particle properties of bagasse ash were characterized by sieve residue test, BET, particle size distribution test and particle shape test, the effects of bagasse ash particle properties on the strength and chloride resistance of bagasse ash mortar were investigated. The results show that TEA optimizes the particle size distribution of bagasse ash, and the proportion of particles smaller than 32 μm increases by 8.2 percentage point, the specific surface area increases to 5.503 5 m²/g, and the particle shape tends to be spherical under the optimal addition of 0.08% (mass fraction).Meanwhile, the strength and chloride resistance of bagasse ash mortar show a pattern of increase first and then decrease with the increase of TEA content; the compressive strength of bagasse ash mortar increases by 19.88% and the chloride ion diffusion coefficient drops by 79.63% compared with normal concrete when TEA dosage is optimally at 0.08%. The mechanism of the influence of bagasse ash particle properties on the performance of bagasse ash mortar is revealed by X-ray diffraction (XRD) and mercury intrusion porosimetry (MIP). Results show that the pozzolanic activity of bagasse ash optimized by TEA is enhanced, and more hydration products are generated in the bagasse ash mortar matrix to improve the compactness. The optimized bagasse ash particles give full play to the filling effect, reduce the void ratio of bagasse ash mortar, and improve the the mortar strength and resistance to chloride salt erosion.