煤矸石砂浆的孔结构与强度的关系

Relationship between the pore structure and strength of coal gangue mortar

为了研究煤矸石砂浆孔结构特征与力学强度的关系,利用AutoPore IV型材料细孔隙测定仪等仪器分析了不同煤矸石集料及掺量下砂浆的孔结构特征及力学性能变化规律,并探讨了力学强度与分形维数及孔径分布等的关系。研究表明:随着煤矸石集料掺量的增加,煤矸石砂浆的力学性能并没有明显降低;煤矸石砂浆孔结构具有分形特征,在一定条件下,孔分形维数可以评定煤矸石砂浆孔结构特征;煤矸石砂浆强度与孔结构有一定关联关系,随着孔径增大,孔隙率增加,孔分形维数减小,砂浆强度呈递减趋势;小于20 nm的无害孔越多,大于100 nm的大孔越少,煤矸石砂浆的抗压及抗折强度越高。

Relationship between the pore structure and strength of coal gangue mortar was investigated in this paper.The mechanical properties of mortar containing coal gangue were measured and the pore structure of mortar was also investigated by using AutoPore IV mercury porosimeter.Results show that,with the increase of coal gangue sand,mechanical properties of coal gangue mortar is not significantly reduced.The pore structures of coal gangue mortar have typical fractal nature.In given conditions fractal dimension can assess the characteristics of pore structure.The strength of coal gangue mortar has a certain relation to the pore structure.The larger pore diameter of coal gangue mortar is,the bigger porosity of coal gangue mortar is,the smaller fractal dimension of coal gangue mortar is,the lower performance of coal gangue mortar becomes.With the increase of small size pores less than 20 nm and decrease of large size pores beyond 100 nm,the improvement of compressive and flexural strength of coal gangue mortar become larger.