矸石膏体粗集料级配优化试验研究

Experimental investigation on coaras materal gradation optimization of gangue paste

在矸石膏体充填开采中,粒径为5~25 mm的矸石占矸石膏体总质量的30%~40%,其粒径级配对矸石膏体力学性能具有重要影响。为了得到粒径为5~25 mm矸石的最佳级配,根据Talbol理论进行连续级配设计,制得矸石膏体浆料,对其可泵性进行测定;然后将其制成矸石膏体试样,标准养护28 d后,对其进行单轴压缩试验以测定其抗压强度、弹性模量等。结果表明,保持矸石、粉煤灰、水泥占膏体总质量的62.5%,29.2%,8.3%,并取粒径为0~5 mm的矸石占矸石总质量的40%时,随着Talbol幂指数逐渐增大,膏体浆料的坍落度及扩展度具有先增大后减小的变化趋势;泌水率具有逐渐增大的变化趋势;膏体试样的抗压强度和弹性模量具有先增大后减小的变化趋势。结合膏体可泵性及力学性能测定结果,当Talbol幂指数为0.5时,粒径为5~10,10~15,15~20,20~25 mm的矸石分别占矸石总质量的37.9%,8.5%,7.2%,6.4%,即为矸石膏体粗集料最佳级配。

In the process of the gangue paste filling and mining project, the grain size of gangue which is 5～25 mm makes up about 30% - 40% of the total mass of the gangue paste, and the size distribution of it is of great importance to the mechnical performance of the gangue paste. In order to get the 5 - 25 mm of grain size of gangue paste in a suitable gradation, based on the theory of Talbol, a sample of gangue paste is made to measure their pumpability. Then we need contiguous gradation design, standard curing the sample of gangue paste in 28 days and uniaxial compression test to determine the compressive strength, elastic modulus, etc. Results show that keep coal gangue, fly ash, cement accounted for 62.5 %, 29. 2% and 8.3% of the total quality of gangue paste as well as the grain size of 0 -5 mm accounted for 40% of the total quality of gangue. Meanwhile ,with the gradual increase of Talbol＇ s power index, slump and extension firstly increased and then decrease, and exudation rate increased gradually;the compressive strength and elastic modulus of the paste sample firstly increased and then decrease. When Talbol＇ s power index of 0.5 and combined the results of the paste pumpability and mechanical property, the gangue grain size of 0 - 5,5 - 10,10 - 15,15 - 20 and 20 - 25 mm accounted respectively for 37.9%, 8.5% ,7.2% and 6.4% of the total mass of the gangue is the suitable gradation of the gangue.