高级检索+

钢纤维类型对玄武岩纤维混凝土力学性能的影响

Influence of steel fiber type on mechanical properties of basalt fiber concrete

  • 摘要: 为探究钢纤维类型及掺量对玄武岩纤维混凝土(BFRC)力学性能产生的影响,在BFRC中加入3种类型的钢纤维(端钩型、波浪型、镀铜型),钢纤维体积掺量分别为0,0.8%,1.0%,1.2%.通过建立灰色理论GM(1,9)和BP神经网络2种模型预测混凝土抗压强度并对比其可靠性,结合核磁共振试验测试混凝土内孔隙变化规律.结果表明:随着钢纤维体积掺量的增加,BFRC抗压强度呈现先增大后减小趋势,其中抗压强度最优组为体积掺量1.0%的端钩型钢纤维组,14 d抗压强度为44.51 MPa.由于钢纤维表面锈蚀,28 d抗压强度减少至43.13 MPa;建立灰色理论GM(1,9)模型和BP神经网络模型,2种模型预测精度均可达到要求.但BP神经网络的预测精度更高、稳定性更好,平均相对误差为3.81%,灰色理论模型平均相对误差为7.55%;随着钢纤维体积掺量增加,混凝土中胶凝孔、毛细孔占比先增加后减小,因此合理加入钢纤维可使BFRC中孔隙结构得到优化,混凝土抗压强度得到提升.

     

    Abstract: In order to investigate the effects of steel fiber types and dosage on the mechanical properties of basalt fiber reinforced concrete(BFRC), three types of steel fibers(end-hook type, wave type, and copper-plated type) were added to BFRC at steel fiber volume dosage of 0, 0.8%, 1.0%, and 1.2%, respectively. Grey theory GM(1,9) and BP neural network models were established to predict the compressive strength of concrete and their reliabilities were compared, and nuclear magnetic resonance testing was combined to test the change patterns of pores in concrete. The results show that with the increase of steel fiber content, the compressive strength of BFRC first increases and then decreases. Among them, the group with the best mechanical properties is the end-hook type steel fiber group with a content of 1.0%. The compressive strength at 14 days is 44.51 MPa. Due to surface corrosion of the steel fiber, the compressive strength at 28 days decreases to 43.13 MPa. The grey theory GM(1,9) model and the BP neural network prediction model are established, for which the prediction accuracy of both models meets the requirements. However, the BP neural network has higher prediction accuracy and better stability, with an average relative error of 3.81%, and the average relative error of the grey theory model is 7.55%. As the volume of steel fiber increases, the proportion of cementitious pores and capillary pores in concrete first increases and then decreases. Therefore, reasonable addition of steel fibers can optimize the pore structure in BFRC and improve its concrete compressive strength.

     

/

返回文章
返回