煤矸石集料的加速风化制度研究

Study on Accelerated Weathering System of Coal Gangue Aggregate

本文以三种不同排放地的原状煤矸石为研究对象,分别采用干湿循环、冻融循环以及耐崩解性试验对煤矸石集料进行加速风化,旨在研究煤矸石的风化特性。以加速风化后的煤矸石集料质量损失率和压碎值指标对煤矸石风化特性进行表征,研究加速风化制度、颗粒粒径、服役状态对煤矸石集料风化特性的影响,同时采用XRD、SEM以及EDS微观测试手段揭示煤矸石的风化机理。结果表明:采用干湿循环方式得到的煤矸石集料质量损失率和压碎值指标与自然状态下煤矸石集料风化180 d的最为接近,同时煤矸石集料粒径越大越容易发生风化,且服役状态下,煤矸石集料的风化作用不明显。微观测试结果表明,煤矸石风化机理为在风化过程中煤矸石内部的矿物组成及结构受到破坏,导致煤矸石发生崩解、脱落,而服役状态下的煤矸石由于被胶凝材料包裹,风化概率有效减小。

Three kinds of original coal gangue from different emission places were taken as the research object,and the dry-wet cycle,freeze-thaw cycle and disintegration resistance test were used to accelerate the weathering of coal gangue aggregate,aiming to study the weathering characteristics of coal gangue.The weathering characteristics of coal gangue aggregate were characterized by the mass loss rate and crushing value index after accelerated weathering.The effects of accelerated weathering system,particle size and service state on the weathering characteristics of coal gangue aggregate were studied.At the same time,the weathering mechanism of coal gangue was revealed by XRD,SEM and EDS.The results show that the mass loss rate and crushing value index of coal gangue aggregate obtained by accelerated weathering of dry-wet cycle are closest to coal gangue aggregate weathered for 180 d under natural state.Moreover,the larger the particle size of coal gangue aggregate,the more likely it is to be weathered,and the weathering of coal gangue aggregate is not obvious under service state.The microscopic test results show that the weathering mechanism of coal gangue is that the mineral composition and structure inside the coal gangue are destroyed during the weathering process,resulting in disintegration and shedding,while the coal gangue in the service state can effectively reduce its weathering due to the encapsulation of cementitious materials.