Sulfate resistance of high performance concrete with non-spontaneous combustion coal gangue coarse aggregate
In order to expand the application range of non-spontaneous combustion coal gangue(NCCG)concrete and reduce the environmental pollution caused by coal gangue stacking,NCCG is substituted for natural gravel to prepare green high-performance concrete.The effects of different water-binder ratio,coarse aggregate substitution rate,mineral admixture type and dosage,water-cement ratio of wolfing slurry on its sulfate attack resistance were systematically studied.The loss mechanism of wolfing slurry was investigated by SEM-EDS and XRD.The results showed that the higher the water-binder ratio is,the higher the damage index is.The best sulfate resistance was obtained by mixing 20％slag powder and 10％mass fraction flv ash.Silica fume coated NCCG aggreeate has no obvious improvement in sulfate resistance.The larger the NCCG substitution rate is,the larger the water-binder ratio is,the more ettringite and gypsum will be generated,and the least erosion products will be generated when fly ash and slag powder are mixed and it is suggested that the NCCG substitution rate should not exceed 30％in the project,and two mineral admixtures should be used in a 2∶1 ratio of slag powder and fly ash.
万方数据
维普
