粉煤灰掺量对煤矸石骨料混凝土性能影响研究

为探讨粉煤灰作为矿物掺合料对煤矸石骨料混凝土性能的影响，在制备煤矸石骨料混凝土试件时，掺入0%、15%、25%、35%、50%的粉煤灰来取代等量的水泥，进行抗压强度、碳化性能及干燥收缩性能试验研究。结果表明，煤矸石混凝土的抗压强度随粉煤灰掺量的增加而有所降低，且均低于未掺粉煤灰时的混凝土抗压强度，但当掺量为15%时，煤矸石混凝土的90 d抗压强度超过同龄期未掺粉煤灰时的混凝土强度；当粉煤灰掺量不超过35%时，对煤矸石混凝土的碳化性能影响不大，粉煤灰掺量达到50%时，煤矸石混凝土的抗碳化能力降低明显；随粉煤灰掺量的增加，煤矸石骨料混凝土的干燥收缩性能得到改善，50%粉煤灰掺量时干燥收缩率最小。试验表明，适量掺入粉煤灰能改善煤矸石骨料混凝土的后期强度及干燥收缩性能，且对碳化性能影响不大，这为煤矸石骨料混凝土掺粉煤灰的应用提供了试验依据。

Effect of Fly Ash Content on the Performance of Coal Gangue Aggregate Concrete

To study the influence of fly ash as a mineral admixture on gangue aggregate concrete properties, 0%, 15%, 25%, 35%, 50% fly ash was mixed to replace the same amount of cement during the preparation of coal gangue aggregate concrete specimens, and then the compressive strength, carbonation performance and drying shrinkage test were studied. The results show that the compressive strength of coal gangue concrete decreases with the increase of the dosage of lfy ash and were lower than the compressive strength of concrete mixed with lfy ash, but when the content is 15%, coal gangue concrete 90 d compressive strength was more than the strength of concrete without lfy ash in the same age stage; lfy ash has little effect on the carbonization properties of coal gangue concrete when the dosage of lfy ash is no more than 35%, but if dosage reached 50% the carbonation resistance of coal gangue concrete is reduced signiifcantly; with the increase of lfy ash, coal gangue aggregate concrete drying shrinkage performance can be improved, drying shrinkage is minimal when the content of lfy ash is 50%. Tests have shown that moderate dosage of lfy ash can improve the later strength of coal gangue aggregate concrete and drying shrinkage performance, which provide a experimental basis for the application of coal gangue concrete mixing lfy ash.