自燃煤矸石骨料强化及其对混凝土力学性能的影响  

Strengthening of Spontaneous Combustion Coal Gangue Aggregate and Its Effect on Mechanical Properties of Concrete

作　　者：李辉 李冬 刘世 LI Hui;LI Dong;LIU Shi(College of Civil Engineering,Liaoning Technical University,Fuxin 123000,China;Key Laboratory of Coal Gangue Resource Utilization and Energy-Saving Building Materials,Fuxin 123000,China;Key Laboratory of Green Mining of Coal Resources in Xinjiang,Wulumuqi 830000,China)

机构地区：[1]辽宁工程技术大学土木工程学院,阜新123000 [2]辽宁省煤矸石资源化利用及节能建材重点实验室,阜新123000 [3]新疆煤炭资源绿色开采教育部重点实验室,乌鲁木齐830000

出　　处：《硅酸盐通报》2025年第3期981-991,共11页Bulletin of the Chinese Ceramic Society

基　　金：辽宁省高等学校基本科研项目(LJKQZ20222268,JYTMS20230817);新疆煤炭资源绿色开采教育部重点实验室开放基金(KLXGY-KB2416)。

摘　　要：自燃煤矸石用作混凝土骨料时,物理性能不及天然碎石,为了进一步扩展自燃煤矸石在建材领域资源化利用,采用水泥浆对其进行强化处理,研究了裹浆强化(水灰比为0.5~1.0)、复合强化(水玻璃浸泡、内掺硅灰、加压浸泡)对自燃煤矸石粗骨料表观密度、吸水率、压碎值、针片状含量和粒径分布的影响。分析了各强化方式对混凝土立方体抗压强度与劈裂抗拉强度的变化。总结了骨料强化后的轴长比、圆度、周长棱角性指数等形状参数的变化和对混凝土强度的影响,引入分形几何,通过试件破坏时裂缝的分形维数验证骨料形状对混凝土强度的增强效果。试验结果表明:当水灰比为0.7时裹浆强化的骨料性能最佳,混凝土28 d抗压强度较未强化试件提升了11.08%;复合强化的三种方法(水玻璃浸泡、内掺硅灰、加压浸泡)均可进一步强化骨料,混凝土28 d抗压强度较未强化试件分别提升了25.76%、22.44%和25.21%。骨料的形状参数和混凝土破坏时裂缝的分形维数可以定量反映骨料强化对混凝土强度的提升。When spontaneous combustion coal gangue is utilized as an aggregate in concrete,its physical properties are often inferior to those of natural gravel.To enhance its resource utilization in building materials,it can be reinforced with cement slurries.The effects of slurry wrapping reinforcement(water-cement ratio is 0.5~1.0)and composite reinforcement(water glass soaking,silica fume doping,pressure soaking)on the apparent density,water absorption,crushing value,needle-shaped flake content and particle size distribution of spontaneous combustion coal gangue aggregate were investigated.The changes in compressive strength and splitting tensile strength of concrete cube with each strengthening method were analyzed.Changes in shape parameters such as axle length ratio,roundness,and perimeter angularity coefficient after aggregate strengthening and their influence on concrete strength were summarized.Fractal geometry was introduced to verify the enhancement effect of aggregate shape on concrete strength through the fractal dimension of cracks at the time of specimen destruction.The test results show that:when the water-cement ratio is 0.7,the performance of the aggregate strengthened by coating is the best,and the 28 d compressive strength of concrete increases by 11.08%.The aggregate can be further strengthened by three methods(water glass immersion,silica fume doping,and pressure immersion)in composite slurry strengthening,and the 28 d compressive strength of concrete increases by 25.76%,22.44%and 25.21%,respectively.The shape parameters of aggregate and the fractal dimension of cracks when concrete fails can quantitatively reflect the enhancement of concrete strength by aggregate strengthening.

关 键 词：混凝土 破坏形态 自燃煤矸石 骨料强化 形状参数 分形维数 

分 类 号：TU528[建筑科学—建筑技术科学]