1 西安科技大学建筑与土木工程学院, 西安 710054
2 西安建筑科技大学土木工程学院, 西安 710054
为促进寒冷地区煤矸石在混凝土中的应用, 通过机械-微波方式对煤矸石进行复合活化, 从表观形貌、质量损失率、相对动弹性模量、抗压强度和劈裂抗拉强度等方面对煤矸石粉混凝土的损伤劣化规律进行了研究, 并使用扫描电子显微镜、核磁共振波谱仪和X射线衍射仪等研究了活化煤矸石粉对混凝土抗冻性能的改性机理。结果表明: 20%(质量分数)掺量下活化煤矸石粉对混凝土抗冻性能改善效果最好, 且经300次冻融循环后, 质量损失率和相对动弹性模量分别为2.32%和91.32%, 抗压强度和劈裂抗拉强度分别下降了16.40%和26.12%; 活化煤矸石粉能填充、细化孔隙, 且其二次水化能消耗水泥水化产物Ca(OH)2, 产生C-S-H和C-A-S-H, 提升水泥石密实程度, 改善孔结构, 使大孔占比减少。
混凝土 煤矸石粉 抗压强度 抗冻性能 劣化规律 损伤机理 concrete coal gangue powder compressive strength frost resistance deterioration law damage mechanism
Author Affiliations
Abstract
1 Department of Physics, Wuhan University, Wuhan 430072
2 Department of Physics, Tsinghua University, Tsinghua-Foxconn Nanotechnology Research Center, Beijing 100084
3 Center of Nanoscience and Nanotechnology Research, Wuhan University, Wuhan 430072
The third-order susceptibility of multiwalled carbon nanotubes (MWCNTs) grown on Si substrate were measured using reflective Z-scan (RZ-scan) technique with femto-second laser pulses at 790 nm. The nonlinear absorption coefficient 'beta' and nonlinear refraction index 'gamma' were measured to be about 9*10^(2) cm/GW and 9.6*10^(-3) cm2/GW, respectively. This is about one order of magnitude larger than the measurement of MWCNTs on transparent quartz substrate. The enhanced optical nonlinearities are contributed by the enhanced local field and the photoinduced off-resonant absorption of the 'pi'-plamon of MWCNTs on Si.
190.4400 Nonlinear optics, materials 240.4350 Nonlinear optics at surfaces 320.7110 Ultrafast nonlinear optics Chinese Optics Letters
2005, 3(0s): 213
