纤维网格布表层强化混凝土力学性能研究

Mechanical properties of concrete strengthened with fiber meshes

机场水泥混凝土道面表面砂浆层易产生开裂、磨损和剥落等问题,严重影响道面正常使用和安全性能。通过在混凝土表层砂浆层中布设纤维网格布的方式强化机场道面的表面性能,首先,使用正交设计法,探究混凝土不同组分对其抗折强度的影响,得到了强度最优配合比;然后,基于此配合比,对碳纤维、芳纶纤维和玄武岩纤维网格布强化混凝土的抗折强度和耐磨耗性能开展试验研究;最后,试验结果表明:水灰比对混凝土抗折强度影响最大,且当水灰比为0.43、砂率为28%、细度模数为2.8时抗折强度最大;3种网格布中碳纤维对抗折强度增强效果最好,3,7,14 d龄期时,混凝土抗折强度分别提高了13.6%,14%,20.8%,达到4.5,5.54,6.67 MPa,其次是芳纶纤维;芳纶纤维网格布对耐磨耗性能增强效果最好,其次是玄武岩纤维。试验结果表明芳纶纤维更适于水泥混凝土道面表层强化。

The mortar layer of a cement concrete airport pavement surface is prone to cracking,abrasion and spalling,which seriously affects the normal use and safety performance of pavements.The surface performance of an airport pavement is strengthened by laying fiber meshes on the mortar layer of the concrete surface.Firstly,an orthogonal design method is used to explore the influence of different components of concrete on its flexural strength,and the optimal mix proportion is obtained.Based on the mix proportion,the flexural strength and wear resistance of carbon fiber,aramid fiber and basalt fiber meshes reinforced concrete are then tested.The results show that the water/cement ratio has a greatest influence on the flexural strength of concrete,and the flexural strength is the largest when the water/cement ratio is 0.43,the sand ratio is 28%and the fineness modulus is 2.8.Among the three kinds of fiber meshes,carbon fiber meshes have a best effect on the flexural strength.At an age of 3 d,7d and 14 d,the flexural strength of concrete increases by 13.6%,14%and 20.8%and reaches 4.5 MPa,5.54 MPa and 6.67 MPa.Aramid fiber meshes have a best effect in enhancing the wear resistance.Basalt fiber meshes are the least.According to the comprehensive test results,aramid fiber is more suitable for strengthening the surface of cement concrete pavements.