风积砂-煤矸石混凝土基本力学特性研究OA

The reserves of aeolian sand(AS)and bulk solid waste coal gangue(CG)in Northern Shaanxi are rich with lower comprehensive utilization rate.It is of great practical significance to realize the resource utilization of the two in the field of building materials.The AS-CG concrete was prepared with raw materials of CG in Northern Shaanxi mining area and AS in Mu Us Desert.The effects of coal gangue replacement rate(CGR)and aeolian sand replace-ment rate(A SR)on the workability(slump)and mechanical properties(compressive strength)of concrete were studied.The influence mechanism of CG and as on the compressive strength of concrete was revealed by scanning electron microscope(SEM)and X-ray diffraction(XRD).The results show that the slump of concrete increases with the increase of A SR and decreases with the increase of CGR.The compressive strength of concrete increases first and then decreases with the increase of ASR and CGR.When ASR=25％and CGR=25％,the compressive strength of concrete reaches the maximum.The reason of AS affecting the mechanical properties of concrete is that it can im-prove the aggregate particle gradation and ITZ structure;The reason of CG affecting the mechanical properties of concrete is its pore development,strong water absorption,low strength and certain chemical activity.Therefore,it is feasible to prepare concrete with AS and CG.