高寒山区机制砂在高速公路C50预制T梁中的应用技术研究

Research on application technology of machine sand in alpine and cold mountain to C50 precast T beam of expressway

高寒山区机制砂在高速公路预制T梁中的应用关键技术研究,解决了目前高寒山区高速公路建设施工中河砂资源匮乏、运输成本高、机制砂使用过程中T梁存在易开裂、外观差、混凝土控制难、黏度大等技术难题。目前使用机制砂生产预制T梁的耐久性也受到很多质疑,机制砂制T梁在很多地区仍然被交通主管部门和建设单位禁止,系统研究了机制砂及其参数对预制T梁混凝土及其T梁外观、回弹的影响,同时全面研究了机制砂预制T梁混凝土配合比关键点、P·O 52.5及P·O 42.5级水泥和外加剂的性能调配、黏度、耐久性、微观分析等核心问题。最终掌握了机制砂在高速公路预制T梁中的运用关键技术,为C50预制T梁大规模使用机制砂打下良好的基础,积累施工经验,为机制砂全面替代河砂获得了可靠的理论依据,节约能源。

Research on the key technology of the application of machine-made sand in the prefabricated T-beam of expressway in the alpine mountain area,which solves the technical problems such as lack of river sand resources,high transportation costs,easy cracking,poor appearance,difficult concrete control and high viscosity of the T-beam during the use of machine-made sand in expressway construction in the alpine mountain area.At present,the durability of the prefabricated T-beam produced by machine-made sand is also questioned,Machine made sand T-beam is still prohibited by transportation authorities and construction units in many areas.It systematically studies the influence of machine made sand and its parameters on the appearance and resilience of precast T-beam concrete and its T-beam,and comprehensively studies the key points of mix proportion of machine made sand precast T-beam concrete,the performance mixing,viscosity,durability,micro analysis and other core issues of P·O 52.5 and P·O 42.5 cement and additives.Finally,I mastered the key technology of the application of machine-made sand in the prefabricated T-beam of expressway,laying a good foundation for the large-scale use of machine-made sand in C50 prefabricated T-beam,accumulating construction experience,obtaining a reliable theoretical basis for the comprehensive replacement of river sand by machine-made sand,and saving energy.