功能性轻集料及高比强轻质混凝土开发与应用

发布时间：2018-06-12 05:06

本文选题：轻质高强 + 免烧轻骨料　；参考：《东南大学》2017年硕士论文

【摘要】：随着建筑节能要求的提高,轻质高强与保温一体化是建筑材料发展趋势之一。轻骨料泡沫混凝土兼具泡沫混凝土轻质保温与轻骨料混凝土高比强的优势于一体,成为高强保温材料的发展方向。制备高比强免烧轻骨料,研究物料性能、用水量、核-壳层厚度关系、养护方式等因素与轻骨料性能关系,研究表明,使用3mm直径EPS颗粒作为内核,物料比例为C:FA:CH=5:4:1并控制壳层厚度为2mm、成球用水量为15%,采用75:蒸养条件制备700级轻骨料,其筒压强度为8.OMPa。在核壳型免烧轻骨料研究基础上进一步采用相变材料制备相变储热型免烧轻骨料,制备1400kg/m~3密度等级轻骨料混凝土,28d抗压强度分别为 12.5MPa、18.2MPa,导热系数分别为 0.26W/(m·K)、0.30W/(m·K)。研究工程用轻骨料混凝土流变性能,分析了流变性能指标(屈服剪切应力σ0、塑性粘度n)与混凝土新拌性能、泵送性能关系,浆体粘度合理范围为2.0Pa·s～3.0Pa·s,屈服剪切应力合理范围为75Pa～125Pa。分析了孔隙率与孔径分布对轻骨料混凝土性能影响,采用MIP法研究轻骨料对基体孔结构的影响,轻骨料掺量为30%、40%时基体相平均孔径分别为20.4nm、31.4nm,28d抗压强度分别为37.5MPa、21.3MPa。研究了轻骨料多孔混凝土泵送性能,结果表明,保证轻骨料多孔混凝土泵送性时压力泌水率BP合理范围为35%～45%,V140范围为2～11mL。采用混料设计方法研究浆体、轻骨料、泡沫体积分量对轻骨料泡沫混凝土性能影响,使用不同拟合方式优选得到得到混凝土性能回归方程,并通过回归方程对混凝土性能进行预测,优化不同密度等级配合比,制备高比强、低导热系数轻骨料泡沫混凝土。优化后1400 kg/m~3密度等级轻骨料泡沫混凝土 28d抗压强度为30.3MPa,导热系数为0.262W/(m·K),对比普通轻骨料混凝土,强度与保温性能都显著提升。
[Abstract]:With the improvement of building energy conservation requirements, the integration of lightweight and high strength and heat preservation is one of the development trends of building materials. Light aggregate foam concrete has the advantages of light thermal insulation of foam concrete and high ratio of light aggregate concrete, and has become the development direction of high strength insulation material. The properties of lightweight aggregates with high specific strength and no burning were studied. The relationship between material performance, water consumption, core-shell thickness and curing mode was studied. The results showed that the 3mm diameter particles were used as the core. The material ratio is CFAA: Ch 5: 4: 1 and the shell thickness is 2 mm and the water consumption is 15 mm. The 700 grade lightweight aggregate is prepared by 75: evaporation condition. The cylinder pressure strength is 8.OMPa. Based on the study of core-shell non-fired lightweight aggregate, phase change material was further used to prepare phase-change heat storage non-fired lightweight aggregate. The compressive strength of 1400kg/m~3 density grade lightweight aggregate concrete was 12.5MPa (18.2 MPa) for 28 days, and the thermal conductivity was 0.26W / m ~ (-1) 0.30W / m ~ (-1) K, respectively. The rheological properties of lightweight aggregate concrete used in engineering are studied. The relationship between the rheological properties (yield shear stress 蟽 0, plastic viscosity n) and the fresh mixing performance of concrete is analyzed. The relation of pumping performance, the reasonable range of slurry viscosity is 2.0 Pa / s, and the reasonable range of yield shear stress is 75 Pa / 125Pa. The effects of porosity and pore size distribution on the properties of lightweight aggregate concrete were analyzed. The effect of light aggregate on matrix pore structure was studied by MIP method. The pumping performance of porous lightweight aggregate concrete is studied. The results show that the reasonable range of pressure bleeding rate BP is 35 ~ 45V _ (140) and 21.11 mL / L when the pumping property of lightweight aggregate porous concrete is guaranteed. The effects of slurry, lightweight aggregate and foam volume component on the properties of lightweight aggregate foam concrete were studied by mixing design method. The regression equation of concrete performance was obtained by using different fitting methods. The performance of concrete was predicted by regression equation, and the mix ratio of different density grades was optimized to prepare high ratio and low thermal conductivity lightweight aggregate foam concrete. After optimization, the compressive strength and thermal conductivity of 1400 kg/m~3 density grade lightweight aggregate foam concrete are 30.3MPa and 0.262 W / m K ~ (-1) respectively. Compared with ordinary lightweight aggregate concrete, the strength and thermal insulation properties are improved significantly.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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