再生粗骨料对再生混凝土基本力学及抗冻性能的影响研究

发布时间：2018-04-15 21:41

本文选题：再生混凝土 + 替代率　；参考：《宁夏大学》2017年硕士论文

【摘要】：随着社会的发展,我国城市建设逐渐加速,废旧建筑物的拆除量也逐年增加,建筑垃圾也越来越多。然而,大部分建筑废弃物的处理方式是填埋或露天堆放,浪费土地资源破坏生态环境,为此,再生混凝土技术应运而生,它能使建筑废弃物循环利用从而减少污染,对实现可持续发展具有重要意义。本文在国内外研究基础之上,研究了再生粗骨料的基本物理性质及再生混凝土的和易性能,重点分析再生粗骨料对再生混凝土基本力学及抗冻性能的影响,主要研究干燥状态、饱和状态、水泥浆包裹状态三种状态下再生粗骨料在9.5mm～16mm、16mm～19mm、19mm～26.5mm三个粒径范围内以替代率为0、20%、40%、60%、80%、100%等质量替代天然骨料的再生混凝土抗压强度和劈裂拉伸强度,同时在以上三种状态三种粒径的替代率下,通过冻融试验后质量损失率与相对动弹性模量两个指标评定抗冻性能的优劣。本论文最终研究结果如下:(1)力学性能方面:在相同径范围内等质量替代时,干燥状态下的再生粗骨料混凝土抗压强度最高;在粒径范围为19mm～26.5mm内,饱和状态下的再生粗骨料混凝土抗压强度最低;在水泥浆包裹状态下,19mm～26.5mm再生粗骨料混凝土抗压强度最高;在9.5mm～16mm粒径范围内,饱和状态下再生粗骨料混凝土劈裂拉伸强度最低;在19mm～26.5mm粒径范围内,干燥状态下再生粗骨料混凝土劈裂拉伸强度最低;在干燥状态下,19mm～26.5mm范围内的再生粗骨料混凝土劈裂拉伸强度最低;在水泥浆包裹状态下,19mm～26.5mm范围内的再生粗骨料混凝土劈裂拉伸强度最低。(2)抗冻性能方面:不同状态不同粒径范围内不同替代率下的再生粗骨料混凝土的抗冻性能均差于普通混凝土的抗冻性能;9.5mm～16mm范围内,干燥状态下的再生混凝土抗冻性能优于其它状态下再生混凝土的抗冻性能;16mm～19mm与19mm～26.5mm粒径范围内,饱和状态下的再生混凝土抗冻性能优于其它状态下再生混凝土的抗冻性能;干燥状态与水泥浆包裹状态下,9.5mm～16mm粒径范围内的再生混凝土抗冻性能优于其它粒径范围内的再生混凝土抗冻性能;饱和状态下,16mm～19mm粒径范围内的再生混凝土抗冻性能优于其它粒径范围内的再生混凝土抗冻性能。总之,通过再生粗骨料混凝土的力学及抗冻性能的研究,其成果可为实际工程提供理论参考。
[Abstract]:With the development of society, the urban construction of our country is accelerating gradually, the quantity of scrapped buildings is also increasing year by year, and the construction waste is more and more.However, most of the construction wastes are disposed by landfill or open storage, which wastes land resources to destroy the ecological environment. Therefore, the technology of recycled concrete emerges as the times require, which can make the construction waste recycle and reduce the pollution.It is of great significance to realize sustainable development.On the basis of domestic and international research, the basic physical properties of recycled coarse aggregate and the easy properties of recycled concrete are studied in this paper. The influence of recycled coarse aggregate on the basic mechanics and frost resistance of recycled concrete is analyzed, and the dry state is mainly studied.The recycled coarse aggregate is in the range of 9.5mm / 16mm / 16mm / 19mm / 19mm / 26.5 mm diameter in the three particle sizes range of 9.5mm / 16mm / 19mm / 19mm / 26.5mm, and the compressive strength and splitting tensile strength of recycled concrete which replaces natural aggregate by 100% in replacement of natural aggregate with a substitution rate of 020%.At the same time, under the substitution rate of three kinds of particle size in the above three states, the quality loss rate and relative dynamic elastic modulus after freeze-thaw test were used to evaluate the frost resistance.The final results of this paper are as follows: the compressive strength of recycled coarse aggregate concrete in dry state is the highest when the mass is replaced in the same diameter range, and in the particle size range of 19mm~26.5mm, the compressive strength of recycled coarse aggregate concrete is the highest in the same diameter range.The compressive strength of recycled coarse aggregate concrete under saturated condition is the lowest, the compressive strength of recycled coarse aggregate concrete is the highest under the condition of cement slurry wrapping, and the splitting tensile strength of recycled coarse aggregate concrete under saturated condition is the lowest in the range of 9.5mm~16mm particle size.The splitting tensile strength of recycled coarse aggregate concrete is the lowest in dry state and 19mm / 26.5 mm in dry state.Frost resistance of recycled coarse aggregate concrete in the range of 19mm ~ 26.5mm under cement slurry condition is the lowest. (2) Frost resistance of recycled coarse aggregate concrete under different state, different particle size range and different substitution rate is all different.The frost resistance of concrete is worse than that of ordinary concrete in the range of 9.5mm ~ 16mm,The frost resistance of recycled concrete under dry state is better than that of recycled concrete in other states in the range of 16mm ~ 19mm and 19mm~26.5mm diameter, and the frost resistance of recycled concrete under saturated condition is better than that of recycled concrete in other states.The frost resistance of recycled concrete in the range of 9.5mm ~ 16mm diameter is better than that of recycled concrete in the range of other particle sizes under the condition of dry state and cement slurry.The frost resistance of recycled concrete in the range of 16mm ~ 19mm diameter is better than that of recycled concrete in the range of other particle sizes.In a word, through the research of mechanics and frost resistance of recycled coarse aggregate concrete, the results can provide theoretical reference for practical engineering.
【学位授予单位】：宁夏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528

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