粉煤灰地聚合物力学及耐高温性能研究
发布时间：2019-06-19 23:50
【摘要】：水泥行业由于CO_2排放量巨大已成为低碳改革关注的焦点。随着时代发展,低碳经济将成为水泥行业今后发展的新模式。粉煤灰地聚合物不仅可以实现固体废弃物资源化利用,而且可以部分代替水泥。这对于我国这样一个能源紧缺和环境污染比较严重的国家具有重要意义。本文以碱激发理论和原材料物理化学性质为基础,通过分析粉煤灰地聚合物强度的影响因素得出最佳配比并建立强度发展定性预测模型。通过微观手段以及水化热试验分析粉煤灰地聚合物的水化机理。在上述研究基础上,分析水玻璃模数、水玻璃掺量和矿渣掺量等因素对粉煤灰地聚合物耐高温性能的影响以及影响机理。粉煤灰地聚合物力学性能研究表明,粉煤灰地聚合物抗压强度受水玻璃模数、水玻璃掺量和矿渣掺量影响较大;水玻璃模数1.2、水玻璃掺量20%、矿渣掺量40%、熟石灰掺量3%~10%时,粉煤灰地聚合物28d抗压强度最高可达72.66MPa,符合P·O52.5水泥对抗压强度的要求;粉煤灰地聚合物强度模型由线性增长阶段和平台阶段组成,并以水玻璃模数、水玻璃掺量和矿渣掺量等因素为变量。粉煤灰地聚合物水化机理研究结果表明,粉煤灰地聚合物的水化产物主要包括-Si-O-Al-O-键形成的絮状聚合物凝胶体、C-S-H凝胶体和铁铝酸四钙结晶体;在粉煤灰地聚合物中,溶出的Ca2+和水玻璃胶团中活性Si O_2反应生成C-S-H凝胶,凝胶以胶团为核心生长并与相邻胶团的产物相互搭接形成整体;粉煤灰与矿渣中Si-O键和Al-O键断裂形成低聚单体,在脱水条件下低聚单体与胶核发生聚合,聚合体不断扩大并与相邻胶核聚合形成完整的空间网络结构。粉煤灰地聚合物耐高温性能研究结果表明,在高温作用下,水玻璃掺量高、水玻璃模数低且矿渣掺量高的试件开裂情况较严重,且抗压强度增幅较小特别在800℃后强度显著降低;在高温作用下,浆体失水收缩使结构更加致密;在高温作用下,浆体熔融出现液相,冷却后可形成坚固的玻璃体,从而建立更高强度;试件失水导致开裂和质量损失,骨料与浆体变形不协调导致浆体与骨料分离整体强度下降。
[Abstract]:Due to the huge CO_2 emissions, cement industry has become the focus of low-carbon reform. With the development of the times, low-carbon economy will become a new model of cement industry in the future. Fly ash polymer can not only realize the resource utilization of solid waste, but also partly replace cement. This is of great significance to China, a country with serious energy shortage and serious environmental pollution. Based on alkali excitation theory and physical and chemical properties of raw materials, the optimum ratio of fly ash ground polymer strength is obtained by analyzing the influencing factors of fly ash ground polymer strength, and a qualitative prediction model for strength development is established in this paper. The hydration mechanism of fly ash ground polymer was analyzed by microcosmic means and hydration thermal test. On the basis of the above research, the effects of sodium silicate modulus, sodium silicate content and slag content on the high temperature resistance of fly ash ground polymer and its mechanism are analyzed. The mechanical properties of fly ash polymer show that the compressive strength of fly ash polymer is greatly affected by the modulus of sodium silicate, the content of sodium silicate and the content of slag, when the modulus of sodium silicate is 1.2, the content of sodium silicate is 20%, the content of slag is 40%, and the content of lime is 3% 鈮，
本文编号：2502733
[Abstract]:Due to the huge CO_2 emissions, cement industry has become the focus of low-carbon reform. With the development of the times, low-carbon economy will become a new model of cement industry in the future. Fly ash polymer can not only realize the resource utilization of solid waste, but also partly replace cement. This is of great significance to China, a country with serious energy shortage and serious environmental pollution. Based on alkali excitation theory and physical and chemical properties of raw materials, the optimum ratio of fly ash ground polymer strength is obtained by analyzing the influencing factors of fly ash ground polymer strength, and a qualitative prediction model for strength development is established in this paper. The hydration mechanism of fly ash ground polymer was analyzed by microcosmic means and hydration thermal test. On the basis of the above research, the effects of sodium silicate modulus, sodium silicate content and slag content on the high temperature resistance of fly ash ground polymer and its mechanism are analyzed. The mechanical properties of fly ash polymer show that the compressive strength of fly ash polymer is greatly affected by the modulus of sodium silicate, the content of sodium silicate and the content of slag, when the modulus of sodium silicate is 1.2, the content of sodium silicate is 20%, the content of slag is 40%, and the content of lime is 3% 鈮，
本文编号：2502733
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