机场道面再生混凝土的性能与应用

Properties and applications of recycled concrete for airport pavement

采用掺加优质粉煤灰和高效外加剂的＂双掺＂技术,进行机场道面再生混凝土的强度、抗冻性、抗渗性和耐磨性等室内试验研究和现场应用。同时通过道面再生混凝土的微观结构分析,揭示其性能机理。研究结果表明：所配制的道面再生混凝土性能比普通道面混凝土的性能优,满足机场道面要求,抗折强度较普通道面混凝土提高4%~11%;抗冻等级高达F250,较普通道面混凝土提高200%以上,可以满足严寒地区道面混凝土抗冻要求;道面再生混凝土静水压力抗渗等级较普通道面混凝土提高300%以上;道面再生混凝土耐磨性较普通道面混凝土提高18%~36%。现场配制的再生混凝土和易性好,易于铺筑施工,28 d抗折强度达到5.5 MPa以上,质量检验项目全部符合规范及设计要求,应用效果较好。

The ＂double mixing＂ technique with high quality fly ash and high efficiency admixture was adopted. The strength, the frost resistances, impermeabilities and abrasion resistances of the recycled concrete for airport pavement were tested in laboratory, and then the recycled concrete was applied in field. The mechanism of the pavement recycled concrete＇s properties was studied through analyzing it＇s microstructure. The results show that the properties of the recycled concrete for airport pavement is superior to the normal pavement concrete, and can meet the requirements of airport pavement, the flexural strength is higher than the ordinary pavement by 4%-11%; the frost resistance grade, which is up to F250, increasing by more than 200 % compared with normal pavement concrete, can fulfill the requirement of pavement in the very chilly area; The impermeability grade by hydrostatic pressure method of the recycled concrete for pavement increases by more than 300 % compared with normal pavement concrete; The abrasion resistances of the recycled concrete for pavement increases by 18%-36% compared with normal pavement concrete. The workability of recycled concrete made in field is well, and can be constructed expediently, with the 28-day flexural strength higher than 5.5 MPa. All the quality items meet the requirements of standard and design, and the application effect is well.