煤矸石钢渣混合料耐久性能研究

Study on durability of coal gangue steel slag mixture

将邯郸地区的煤矸石、钢渣和石灰按照一定配比制成混合料,采用均匀试验研究其用于路面基层的耐久性能,进行冻融循环和干湿循环室内试验,用Matlab对试验结果进行回归分析,最后分析钢渣对混合料膨胀的影响。结果表明:5次冻融循环后,6组试件均出现了脱落和强度损失。混合料中各材料掺量对其抗冻性能有一定影响,随石灰掺量的增加,冻融后抗压强度和BDR值先提高后降低;随钢渣掺量的增加,冻融后抗压强度提高,BDR值无明显变化;15次干湿循环后,6组试件强度均提高,干湿循环后抗压强度与冻融后抗压强度规律基本相同;通过与二灰稳定煤矸石混合料进行对比发现,水化反应速率和本身物理性质是影响耐久性能的主要原因;纯钢渣浸水膨胀率小于2%,混合料后期膨胀率几乎不再增长,该混合料的体积稳定性较好。

The coal gangue,steel slag and lime in Handan area are made into a mixture according to a certain ratio.In order to study the durability of the mixture used in the pavement base,the uniform test method is used to carry out the freeze-thaw cycle and dry-wet cycle test by indoor test.The test results are analyzed by regression analysis with Matlab.Finally,the influence of steel slag on the expansion of the mixture is analyzed.The results showed that after five freeze-thaw cycles,the six groups of test blocks all showed shedding and strength loss.The content of each admixture in the mixture has a certain influence on its frost resistance.With the increase of lime content,the compressive strength and BDR value after freeze-thaw increase first and then decrease.With the increase of steel slag content,the compressive strength after freeze-thaw increases and the BDR value does not change significantly.After 15 dry-wet cycles,the strength of the 6 groups of mix proportion test blocks increased,and the compressive strength after dry-wet cycles was basically the same as that after freeze-thaw cycles.By comparing with the lime-fly ash stabilized coal gangue mixture,it is found that the hydration reaction rate and its physical properties are the main reasons affecting the durability.The immersion expansion rate of the steel slag is less than 2%,and the expansion rate of the mixture hardly increases in the later stage.The volume stability of the mixture is good.