【作者】 李海艳； 管学茂；

【Author】 Haiyan Li;Xuemao Guan;School of Material Science and Engineering,Henan Polytechnic University;

【机构】 河南理工大学材料科学与工程学院；

【摘要】 研究了高水灰比(0.6)下,锂铝水滑石(LiAl-LDH)外加剂的粒径对硫铝酸盐水泥熟料凝结时间和早期强度的影响,并通过量热分析,FT-IR,TG-DSC等手段来表征粒径对硫铝酸盐熟料水化过程的影响。四种粒径尺寸的微纳米外加剂由水热/溶剂热法合成,按粒径尺寸由小到大分别记为LDH-1,LDH-2,LDH-3,LDH-4。结果表明,LiAl-LDH微纳米材料均能提高早期强度,并且除了LDH-1,1天和7天的抗压强度随着粒径的增加而降低;凝结时间随着LiAl-LDH掺量的增加呈现出下降的趋势,加入LDH-2外加剂(3%)的硫铝熟料的初凝和终凝时间最短。FT-IR,TG-DSC结果表明:外加剂的加入并未产生新的水化产物,但LiAl-LDH的粒径影响水化产物的含量;添加有LDH-2外加剂的熟料在水化1天时,由于产生了最多的钙矾石和铝胶,从而获得了最高的强度。然而水化热测试表明LiAl-LDH的加入均使得第一水化放热峰值增加,并且粒径尺寸越小,第一水化放热峰值越高;LDH-1外加剂没有表现出最优的性能可能是由于粒径较小,易团聚,没能得到有效的分散。更多还原

【Abstract】 The research presented the early strength development under high water-cement ratio and setting time of sulphoaluminate cement clinker containing LiAl-layered double hydroxide(LDH) 3D micro-nano structures.Four kind of LiAl-LDH which was marked as LDH-1,LDH-2,LDH-3 and LDH-4 with different particle size were synthesized by the hydrothermal/ solvothermal approach..Tested results indicated that LDH significantly improved early compressive strength and reduced setting time of sulphoaluminate cement clinker and the strength improvement and setting time reduce were also dependent on the LDH particle size.Cement clinker containing LDH-2 gave higher compressive strength and shorter setting time(3%by weight) compared with other three LDH particles.The effects of different particle size of LDH on hydration characteristic of cement clinker were also compared in this study by calorimetric analysis,IR-spectroscopy and TG-DSC.The results of IR-spectroscopy and TG-DSC revealed that the addition of LDH did not appear new hydration phase,but the particle size of LDH affect the amount of hydration products.The clinker with LDH-2 produced more alumina gel,which was in good agreement with the experiment result of compressive strength.However,calorimetric analysis results showed that the rate of hydration fell with the increase of particle size.LDH-1particle did not exhibit the highest compressive strength and shortest setting time maybe due to its agglomeration and ineffective dispersion.更多还原