高压脉冲电极间距对破碎后混凝土物理性能影响研究

Study on effect of high voltage pulse electrode spacing on broken concrete physical performance

为了研究高压脉冲电极间距对破碎后混凝土物理性能影响规律,采用4种电极间距开展混凝土的破碎试验,分析电极间距对破碎后的骨料吸水率、失水率、粒度分布、压碎值和表面粗糙度的影响规律。试验结果表明:脉冲破碎后,破碎骨料主要有3种表观形态;随着电极间距的加大,混凝土破碎后粒组呈现多样性,骨料连续级配逐渐形成;大粒组的吸水率较小粒组呈现加速降低的趋势,总体上1 h内,破碎骨料吸水程度迅速达到最大值,粒组为5~20、16~31.5 mm较0.16 h分别提高25.53%和12.86%,至24 h,二者较初期(1 h)仅分别提高18.82%和3.02%;失水方面,大、小粒组的失水率呈现提高的趋势;粒组范围内骨料的质量占比总体上呈现先增加后降低的趋势;同粒组下混凝土压碎值呈现基本不变的情况;破碎产物总体粗糙度呈现先增大后降低的趋势,降低拐点出现在电极间距157.5 mm处。

In order to study on effect of high voltage pulse electrode spacing on broken concrete physical performance,through four electrode spacing in the concrete crush test,analysis of electrode spacing effect on water absorption and loss rate of aggregate,particle size distribution,crushing value and surface roughness.The test results show that after concrete crushed by the pulse,crushed aggregate mainly assumes three kinds of apparent form.With the electrode spacing increasing,concrete crushing grain group present diversity,continuous graded aggregate gradually formed.The water absorption rate of large particle size assumes the albeit slowly trend compared the small one,on the whole,within 1 hour,aggregate absorbent ability quickly reach the maximum,grain group for 5~20 mm and 16~31.5 mm compare 0.16 hours increased by 25.53%and 12.86%respectively,to 24 hours,only increased by 18.82%and 3.02%compared the early time(one hour)condition respectively.For water loss,large and small particle size both show the increase trend.The aggregate particle size mass within the scope shows the tendency of increase after the first reduce overall.The same particle size under the concrete crush value present almost unchanged.Broken product roughness overall present a trend of the first increases first and reduce after,the reduce inflection point is in the electrode spacing of 157.5 mm.