文档介绍：摘要
压碎值用于衡量石料在逐渐增加的荷载下抵抗压碎的能力,是衡量石料力学性质的一项重要指标。
本文首先通过选用料源相同的四档单一粒径 ~,~ 16mm,16mm~19mm,19mm~ 的粗集料进行压碎值试验,研究粗集料的针片状颗粒、粗集料的粒径和施加的荷载水平对压碎值的影响,结果表明:1. 集料中有无针片状颗粒对压碎值有较大的影响,剔除针片状颗粒的压碎值明显小于不剔除针片状颗粒的压碎值,并且,随着粗集料中针片状颗粒含量的增加,压碎值呈增大趋势,集料的粒径越粗,其压碎值受到针片状含量影响程度越大。2. 随着荷载的增大,各档单一粒径粗集料的压碎值均呈增大趋势,且当各档单一粒径粗集料针片状含量相同时,在相同的荷载作用下,粒径越粗的那档料,其压碎值越小。
其次,按不同的级配方案进行压碎值试验,研究多粒径对压碎值的影响,结果表明:,细料含量越少,压碎值就小;也不是粗料含量越少,细料含量越多,压碎值就大;混合料的压碎值并不会随着混合料中某档料含量或任意两档料总含量的变化出现明显线性规律,而是处于波动状态。 Cu 呈现一定的线性关系,总的来说,级配的不均匀系数 Cu 越大,压碎值一般就越小。 CBR 具有良好的相关性,级配的骨架强度 CBR 越大,对应的压碎值越小;CBR 越小,对应的压碎值越大,骨架强度 CBR 反映矿料级配强度,而压碎值的大小反映抵抗压碎的能力, 通过利用试验结果及灰色理论进行综合分析,证明了可以利用压碎值来评价级配的优良。
再次,对工程中的压碎值进行探讨,建议针对不同层位,采用不同的荷载做试验测得压碎值。
最后,对研究成果做了总结,并对进一步研究方向提出了建议。
关键词:针片状颗粒,颗粒破碎,不均匀系数,灰色系统理论
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ABSTRACT
Crushing value is used to measure the capacity to resist crushing under gradually increasing load,which is an important indicator to measure the mechanical properties
of stone.
Firstly, through the selection of the same source material single particle size ~ , ~ 16mm, 16mm ~ 19mm, 19mm ~ for coarse aggregate crushing value experiment. Study needle flake particles of coarse aggregate, the coarse aggregate size and applied load influence on crushing value. Results show that: 1. For needle flake in the aggregate particles has great influence to the crush value, eliminate needle flake particle crushing value are much smaller than not eliminate needle flake particle crushing value, and, as the coarse aggregate in the increase of the content of needle flake particle crushing value showed a trend of increase, the particle size of the coarse aggregate, the crush value influenced by the needle flake content level. 2. With the increase of load, the single particle size of coarse aggregate crushing value all showed a trend of increase, and when all the files of the single particle size of coarse aggregate phase at the same time, the needle flake cont