关键词: 细铁尾矿粉　高强混凝土　核磁共振　孔隙度　抗压强度　抗拉强度

Abstract: In order to study the effect of fine iron tailing powder content on pore structure and mechanical properties of high-strength concrete materials,the micro-pore structure,porosity and mechanical properties of samples with 0%,5%,10%, 15%,20%,25% and 30% fine iron tailing powder content were measured by nuclear magnetic resonance detection device and electro-hydraulic servo press. The effect of fine iron tailing on the porosity,tensile strength and compressive strength of the specimen was analyzed. The results show that:① The T2 spectrum curves of high-strength concrete specimens with fine iron tailing powder all show a three-peak shape. With the increase of fine iron tailing powder content,the porosity of specimens decreases from 2. 81% at 0% to 2. 10% at 30%. The porosity of specimens decreases continuously,and the decline of porosity in the early stage is more significant. ② The internal pore structure of the specimen is dominated by the proportion of micropores and medium pores. With the increase of fine iron tailing powder,the proportion of micropores increases,while the proportion of medium pores,large pores and cracks decreases. The addition of fine iron tailing powder can optimize the internal structure of the concrete. ③ When the iron tailing powder content is 20%,the compressive strength and tensile strength of the specimen are improved,but excessive incorporation will reduce the mechanical properties of the specimen.

Key words: fine iron tailing powder,high strength concrete,nuclear magnetic resonance,porosity,compressive strength, tensile strength