某细骨料粉煤灰基充填注浆试件力学特性研究

Study on Mechanical Properties of a Fine Aggregate Fly Ash Based Filling Grouting Specimen

为了减少煤矸石、粉煤灰堆积带来的环境污染,推动粉煤灰及煤矸石在充填注浆材料中的应用,针对以水泥为主的注浆材料成本高的问题,通过试验法进行了不同煤矸石、粉煤灰配比对充填注浆试件流动性、析水率、结实率、初终凝时间、抗压强度等性能的影响研究。研究结果表明:煤矸石掺量与析水率呈正相关关系,与结实率呈负相关关系;流动度随煤矸石掺量的增大而逐渐增大,初终凝时间随煤矸石掺量的增大连续降低;煤矸石掺量为60%时,煤矸石-粉煤灰-水泥注浆试件峰值强度最大,峰值应变最小,注浆试件表面裂隙和剥落带少;煤矸石细料对浆液离析以及结石体收缩影响大,可降低注浆材料的凝结时间;在水泥掺量40%的条件下,粉煤灰与煤矸石配比2∶3为注浆材料的最佳配比。

In order to reduce the environmental pollution caused by the accumulation of coal gangue and fly ash,and promote the application of fly ash and coal gangue in filling grouting materials,aiming at the problem of high cost of cement-based grouting materials,he effects of different coal gangue and fly ash ratios on the fluidity,water separation rate,setting rate,initial and final setting time and compressive strength of filling grouting specimens were studied by experimental method.The results show that the content of coal gangue is positively correlated with the water separation rate and negatively correlated with the setting rate.The fluidity increases gradually with the increase of coal gangue content,and the initial and final setting time decreases continuously with the increase of coal gangue content.When the content of coal gangue is 60%,the peak strength of coal gangue-fly ash-cement grouting specimen is the largest,the peak strain is the smallest,and the surface cracks and spalling zones of grouting specimen are less.Coal gangue fine materi⁃al has a great influence on slurry segregation and stone shrinkage,which can reduce the setting time of grout⁃ing material.Under the condition of 40%cement content,the ratio of fly ash to coal gangue of 2∶3 is the best ratio of grouting material.