The impact of fly ash content on bond performance of steel bars and their surrounding concrete is studied by means of sticking strain gauges on steel bars. The average bond stress-slip curves, the steel strain-anchor ...The impact of fly ash content on bond performance of steel bars and their surrounding concrete is studied by means of sticking strain gauges on steel bars. The average bond stress-slip curves, the steel strain-anchor location curves, and the bond stress-anchor position curves of the pullout specimens with various fly ash contents are obtained. Results indicate that the bond performance of concrete and steel bars can be improved and the distribution of steel strain along the anchorage length tends to be more uniform by adding fly ash in concrete specimens, and both ultimate bond stress and ultimate slip deformation increase the most when 20% of specimens′ content is fly ash.展开更多
Red mud is a type of highly alkaline waste residue produced in the process of alumina smelting by the Bayer process.Based on the idea of medium calcium content,solid wastes such as red mud and fly ash were used to pre...Red mud is a type of highly alkaline waste residue produced in the process of alumina smelting by the Bayer process.Based on the idea of medium calcium content,solid wastes such as red mud and fly ash were used to prepare non-burnt bricks;and the mass ratio of CaO/SiO2 was selected in the range of 0.88–1.42.Mechanical properties and durability were investigated with a compressive strength test.X-ray diffractometry(XRD),scanning electron microscope(SEM),and Fourier transform infrared spectroscopy(FTIR)techniques were used to characterize the hydration characteristic.The environmental performance was analyzed by Inductively Coupled Plasma Mass Spectrometry(ICP).The results indicated that the mechanical properties and the durability were optimal when the mass ratio of CaO/SiO2 was 1.23.The hydration products were mostly C–S–H gel,ettringite,Na4Ca(Si10All6)O32·12H2O and Ca3Al2(SiO4)(OH)8.They were responsible for the strength development,and the CaO/SiO2 mass ratio of 1.23 had the best polymerized structure.The results of an environmental performance test showed that the heavy metals in the raw materials were well-solidified in the brick.Therefore,this paper provides an effective solution for use of solid wastes in building material.展开更多
The fly ash occasionally has high content of iron oxide and carbon that are good electrical conducting components. This paper investigates the effect of the fly ash used as mineral admixtures on the electrical conduct...The fly ash occasionally has high content of iron oxide and carbon that are good electrical conducting components. This paper investigates the effect of the fly ash used as mineral admixtures on the electrical conductivity of concretes. The electrical properties of concretes using 3 kinds of fly ash with different iron oxide contents have been studied. Experimental results show that at the same fly ash dosage the resistivity of concrete using fly ash with high content of iron oxide is slightly lower than that with low content of iron oxide. However, the concrete resistivity after 14d increases as fly ash dosage increases regardless of iron oxide content in fly ash.展开更多
本文研究了0%、10%、20%、30%、40%粉煤灰掺量对清水混凝土各项基本性能和表观质量的影响。利用Image Pro Plus图像分析软件参数化表征了28d龄期不同粉煤灰掺量清水混凝土的表面色差、气孔孔径分布和面积率等表观质量,对清水混凝土表观...本文研究了0%、10%、20%、30%、40%粉煤灰掺量对清水混凝土各项基本性能和表观质量的影响。利用Image Pro Plus图像分析软件参数化表征了28d龄期不同粉煤灰掺量清水混凝土的表面色差、气孔孔径分布和面积率等表观质量,对清水混凝土表观质量进行了准确的综合量化评估。研究表明,在保证清水混凝土的工作性能、力学性能前提下,20%粉煤灰掺量清水混凝土整体表观质量评价等级为优。最后,试验优选20%粉煤灰掺量的自密实清水混凝土配比成功应用于深圳湾文化广场清水混凝土工程,整体清水效果满足标准验收要求,对清水混凝土在具有大面积无规则流线型多曲面结构特征的实际工程施工应用提供了重要的参考价值和借鉴意义。展开更多
基金Supported by the Program of Excellent Talents in Six Fields of Jiangsu Province(2008183)~~
文摘The impact of fly ash content on bond performance of steel bars and their surrounding concrete is studied by means of sticking strain gauges on steel bars. The average bond stress-slip curves, the steel strain-anchor location curves, and the bond stress-anchor position curves of the pullout specimens with various fly ash contents are obtained. Results indicate that the bond performance of concrete and steel bars can be improved and the distribution of steel strain along the anchorage length tends to be more uniform by adding fly ash in concrete specimens, and both ultimate bond stress and ultimate slip deformation increase the most when 20% of specimens′ content is fly ash.
基金the financial support from the National Natural Science Foundation of China (No.51574024)Fundamental Research Funds for the Central Universities (FRF-TP-18-005B1)Technological Research and Development Programs of China Railways Corporation (No.2017G006-J)
文摘Red mud is a type of highly alkaline waste residue produced in the process of alumina smelting by the Bayer process.Based on the idea of medium calcium content,solid wastes such as red mud and fly ash were used to prepare non-burnt bricks;and the mass ratio of CaO/SiO2 was selected in the range of 0.88–1.42.Mechanical properties and durability were investigated with a compressive strength test.X-ray diffractometry(XRD),scanning electron microscope(SEM),and Fourier transform infrared spectroscopy(FTIR)techniques were used to characterize the hydration characteristic.The environmental performance was analyzed by Inductively Coupled Plasma Mass Spectrometry(ICP).The results indicated that the mechanical properties and the durability were optimal when the mass ratio of CaO/SiO2 was 1.23.The hydration products were mostly C–S–H gel,ettringite,Na4Ca(Si10All6)O32·12H2O and Ca3Al2(SiO4)(OH)8.They were responsible for the strength development,and the CaO/SiO2 mass ratio of 1.23 had the best polymerized structure.The results of an environmental performance test showed that the heavy metals in the raw materials were well-solidified in the brick.Therefore,this paper provides an effective solution for use of solid wastes in building material.
基金Funded by the National Natural Science Foundation of China (No.50404005)
文摘The fly ash occasionally has high content of iron oxide and carbon that are good electrical conducting components. This paper investigates the effect of the fly ash used as mineral admixtures on the electrical conductivity of concretes. The electrical properties of concretes using 3 kinds of fly ash with different iron oxide contents have been studied. Experimental results show that at the same fly ash dosage the resistivity of concrete using fly ash with high content of iron oxide is slightly lower than that with low content of iron oxide. However, the concrete resistivity after 14d increases as fly ash dosage increases regardless of iron oxide content in fly ash.
文摘本文研究了0%、10%、20%、30%、40%粉煤灰掺量对清水混凝土各项基本性能和表观质量的影响。利用Image Pro Plus图像分析软件参数化表征了28d龄期不同粉煤灰掺量清水混凝土的表面色差、气孔孔径分布和面积率等表观质量,对清水混凝土表观质量进行了准确的综合量化评估。研究表明,在保证清水混凝土的工作性能、力学性能前提下,20%粉煤灰掺量清水混凝土整体表观质量评价等级为优。最后,试验优选20%粉煤灰掺量的自密实清水混凝土配比成功应用于深圳湾文化广场清水混凝土工程,整体清水效果满足标准验收要求,对清水混凝土在具有大面积无规则流线型多曲面结构特征的实际工程施工应用提供了重要的参考价值和借鉴意义。
