Aluminium powders were introduced to Al2O3-SiC-C dry ramming mixes in order to improve sintering properties and oxidation resistance according to their service conditions and installation methods. Properties such as b...Aluminium powders were introduced to Al2O3-SiC-C dry ramming mixes in order to improve sintering properties and oxidation resistance according to their service conditions and installation methods. Properties such as bulk density, porosity, modulus of rupture, crushing strength and hot modulus of rupture as a function of aluminium addition were investigated in the present work. The microstructure and thermodynamics for the heat treated specimens were also analyzed. The results show that as aluminium addition increasing, the bulk density of the specimen treated at 220℃ tends to decrease and the apparent porosity increases, the strength of the specimens treated at 1100℃ and 1450℃ increases markedly, the bulk density tends to increase, apparent porosity and linear shrinkage decrease. The HMOR at 1400℃ is enhanced from 1.0 MPa to 3.5 MPa with 3% aluminium. Aluminium is served as sintering agent and anti-oxidant and it will react with CO and CO2 forming Al2O3 , which is helpful to enhance the strength, densify the structure and improve the overall properties.展开更多
【目的】SH+遗址土+生石灰[SH-(C+CaO)]改性夯筑土对遗址夯土具有较好的兼容性,故其耐久性研究在该改性土的应用与推广中是必不可少的。【方法】对SH-(C+CaO)改性夯筑土进行干湿循环、冻融循环、安定性、耐碱性试验,且不同次数均设定为1...【目的】SH+遗址土+生石灰[SH-(C+CaO)]改性夯筑土对遗址夯土具有较好的兼容性,故其耐久性研究在该改性土的应用与推广中是必不可少的。【方法】对SH-(C+CaO)改性夯筑土进行干湿循环、冻融循环、安定性、耐碱性试验,且不同次数均设定为1、3、5、9、15、25和40次,以系统揭示该改性土的物理、力学、水热性能的变化规律,并利用扫描电镜(scanning electron microscopy,SEM)和X射线衍射(X-ray diffraction,XRD)进行定性分析,以孔隙面积占比建立损伤变量,并分析损伤变量与各性能指标的定量关系。【结果】试样外观在40次循环结束后仍然完整。试样的各性能指标随循环次数的增加逐渐衰减,均在第5次和第25次循环处存在明显拐点;各项性能指标损失率较小,损伤变量与各性能指标之间高度相关,且试样在耐碱性试验条件下的损伤程度最小,在安定性试验下的损伤程度最大。循环结束后的SEM和XRD试验结果表明:干湿循环试验下的试样因颗粒团聚产生破坏,长石类和方解石的相对含量降低;耐碱性试验下的试样破坏缓慢,长石类的相对含量减少最多,石英的相对含量增加最多;冻融循环试验和安定性试验下的试样均产生较多裂隙,其中安定性试验下的试样中的长石类相对含量变化较为明显,但冻融循环试验下的试样的矿物成分变化并不明显。【结论】SH-(C+CaO)改性夯筑土在干旱地区常见的碱性环境下表现较优。本文为夯土类遗址文物掏蚀区的保护与修复提供了理论支撑。展开更多
文摘Aluminium powders were introduced to Al2O3-SiC-C dry ramming mixes in order to improve sintering properties and oxidation resistance according to their service conditions and installation methods. Properties such as bulk density, porosity, modulus of rupture, crushing strength and hot modulus of rupture as a function of aluminium addition were investigated in the present work. The microstructure and thermodynamics for the heat treated specimens were also analyzed. The results show that as aluminium addition increasing, the bulk density of the specimen treated at 220℃ tends to decrease and the apparent porosity increases, the strength of the specimens treated at 1100℃ and 1450℃ increases markedly, the bulk density tends to increase, apparent porosity and linear shrinkage decrease. The HMOR at 1400℃ is enhanced from 1.0 MPa to 3.5 MPa with 3% aluminium. Aluminium is served as sintering agent and anti-oxidant and it will react with CO and CO2 forming Al2O3 , which is helpful to enhance the strength, densify the structure and improve the overall properties.
文摘【目的】SH+遗址土+生石灰[SH-(C+CaO)]改性夯筑土对遗址夯土具有较好的兼容性,故其耐久性研究在该改性土的应用与推广中是必不可少的。【方法】对SH-(C+CaO)改性夯筑土进行干湿循环、冻融循环、安定性、耐碱性试验,且不同次数均设定为1、3、5、9、15、25和40次,以系统揭示该改性土的物理、力学、水热性能的变化规律,并利用扫描电镜(scanning electron microscopy,SEM)和X射线衍射(X-ray diffraction,XRD)进行定性分析,以孔隙面积占比建立损伤变量,并分析损伤变量与各性能指标的定量关系。【结果】试样外观在40次循环结束后仍然完整。试样的各性能指标随循环次数的增加逐渐衰减,均在第5次和第25次循环处存在明显拐点;各项性能指标损失率较小,损伤变量与各性能指标之间高度相关,且试样在耐碱性试验条件下的损伤程度最小,在安定性试验下的损伤程度最大。循环结束后的SEM和XRD试验结果表明:干湿循环试验下的试样因颗粒团聚产生破坏,长石类和方解石的相对含量降低;耐碱性试验下的试样破坏缓慢,长石类的相对含量减少最多,石英的相对含量增加最多;冻融循环试验和安定性试验下的试样均产生较多裂隙,其中安定性试验下的试样中的长石类相对含量变化较为明显,但冻融循环试验下的试样的矿物成分变化并不明显。【结论】SH-(C+CaO)改性夯筑土在干旱地区常见的碱性环境下表现较优。本文为夯土类遗址文物掏蚀区的保护与修复提供了理论支撑。
