煤矸石集料路面基层材料应用研究

Study on Application of Coal Gangue Aggregate Pavement Base Material

煤矸石成分复杂,用于路面基层中存在压碎值偏高、施工易压碎、基层混合料强度偏低等问题.文中采用选择性破碎分选工艺制备煤矸石集料,研究了配合比、稳定类型对煤矸石集料路面基层材料的抗击碎性能、力学性能的影响规律.试验表明:选择性破碎分选工艺能显著降低煤矸石集料压碎值及热值指标,制备出高品质的煤矸石集料.虽然与天然碎石相比,煤矸石集料制备的路面基层材料强度偏低,不过10%粉煤灰掺入后,在基层混合料中起到了缓冲作用,使得煤矸石基层混合料击实后的级配变化率降低41.8%,显著改善煤矸石集料路面基层材料的抗击碎性;同时,7 d无侧限抗压强度提高30.9%,达3.52 MPa,28 d抗劈裂性能提高64.3%,达0.46 MPa,90 d抗压回弹模量提高11%,达1383 MPa,显著提高煤矸石集料路面基层材料的力学性能.

The composition of coal gangue is complex,which is used to solve the problems of high crushing value,easy crushing in construction,low strength of base mixture and so on.Coal gangue aggregate was prepared by selective crushing and sorting process,and the influence of mixture ratio and stability type on crushing resistance and mechanical properties of coal gangue aggregate pavement base material was studied.The experiment shows that the selective crushing and sorting process can significantly reduce the crushing value and calorific value of coal gangue aggregate,and prepare high-quality coal gangue aggregate.Although compared with natural crushed stone,the strength of pavement base material prepared from coal gangue aggregate is lower.However,after adding 10%fly ash,it plays a buffering role in the base mixture,which reduces the gradation change rate of the coal gangue base mixture after compaction by 41.8%,and significantly improves the crushing resistance of the coal gangue aggregate pavement base material.Meanwhile,the 7-day unconfined compressive strength increased by 30.9%to 3.52 MPa,the 28-day splitting resistance increased by 64.3%to 0.46 MPa,and the 90-day compressive resilience modulus increased by 11%to 1383MPa,which significantly improved the mechanical properties of coal gangue aggregate pavement base materials.