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为了提高二灰碎石力学强度,假设二灰碎石为一种三级空间网状结构的分散系,即微分散系二灰胶浆、细分散系二灰砂浆与粗分散系二灰碎石。基于抗压强度最优原则,采用垂直振动试验方法(VVTM)确定二灰胶浆与二灰砂浆质量比,基于密度最大原则,采用逐级填充法确定粗集料级配,基于抗压强度最优原则,确定二灰碎石中二灰砂浆用量。提出了基于胶浆原理的二灰碎石组成设计方法,并通过室内试验与现场试验对设计方法进行性能验证。验证结果表明:当石灰与粉煤灰质量比为2∶5时,二灰胶浆力学性能和收缩性能最佳;当细集料质量通过率的递减系数为0.65,二灰与细集料质量比为3∶2时,二灰砂浆力学强度最大;当粒径范围分别为19~37.5、9.5~19、4.75~9.5mm的集料质量比为17∶11∶6时,混合粗集料密度最大;与传统方法设计的二灰碎石试件力学强度相比,基于胶浆原理设计的试件早期(7d)力学强度提高10%以上,后期(180d)力学强度提高20%以上;不同龄期的VVTM试件与现场芯样抗压强度之比平均为0.909,劈裂强度之比平均为0.904,而静压成型试件与现场芯样抗压强度之比为0.457,劈裂强度之比为0.531,说明VVTM比静压法设计二灰碎石更科学。
In order to improve the mechanical strength of lime-fly ash, it is assumed that lime-fly ash is a dispersed system of three-level spatial network structure, ie, microdisperse fly ash mortar, finely divided fly ash mortar and coarsely dispersed fly ash . Based on the principle of optimal compressive strength, the vertical vibration test (VVTM) was used to determine the mass ratio of the two mortar to the two mortars. Based on the principle of maximum density, the gradation of coarse aggregate was determined by the stepwise filling method. Based on the compressive strength You principle, to determine the amount of lime-fly ash mortar. The design method of lime-flyash gravel based on the mortar principle is put forward, and the performance of the design method is validated by indoor test and field test. The results show that when the mass ratio of lime to fly ash is 2: 5, the mechanical properties and shrinkage properties of the fly ash mortar are the best. When the decreasing coefficient of fine aggregate passing rate is 0.65, the fly ash and fine aggregate mass When the ratio is 3: 2, the mechanical strength of lime mortar is the largest; when the particle size range is 19 ~ 37.5,9.5 ~ 19,4.75 ~ 9.5mm aggregate mass ratio of 17:11:6, the mixed coarse aggregate density Compared with the mechanical strength of the lime-flywheel specimen designed by the traditional method, the mechanical strength of the specimen designed based on the mortar principle increased by more than 10% in the early stage (7d) and more than 20% in the late stage (180d) The average ratio of the compressive strength of the VVTM specimens to the live core specimens was 0.909 and the average splitting strength ratio was 0.904. The ratio of the compressive strength of hydrostatic formed specimens to the field core specimens was 0.457. The ratio of splitting strength 0.531, indicating that VVTM is more scientific than limestone in the design of lime-flyash.