摘要
以再生粗集料完全替代天然碎石,再生细集料部分或完全取代机制砂,同时以碱性激发剂激发冶金工业副产物矿渣和燃煤电厂固体废弃物粉煤灰,制备出绿色度高、和易性好的再生集料碱-粉煤灰-矿渣混凝土。研究结果表明:(1)筛选优质的再生集料及调整其级配可以提高混凝土的整体性能;(2)不对再生集料做任何预处理时,可考虑选用20%～60%的再生细集料取代率以获得较高的强度;(3)全再生集料碱-粉煤灰-矿渣混凝土强度接近30MPa,可用于对早期强度要求不高的工程;(4)旧砂浆表面的裂缝虽然能使混凝土更致密,但若裂缝过多,也会延伸至新旧砂浆界面,成为混凝土结构的薄弱环节。
The study proposed the idea that using recycled coarse aggregate instead of crushed limestone completely and using recycled fine aggregate instead of manufactured sand partially or wholly, along with alkali activated slag and fly ash-based cementitious material completely to create alkali activated slag and fly ash-based recycled concrete with high green content and good workability since blast furnace slag is byproduct of metallurgical industry and fly ash is solid waste from coal-fired power plant. The research results show that:(1)Selecting high-quality recycled aggregate and adjusting its gradation can improve the overall performance of the concrete.(2)Alkali activated slag and fly ash-based recycled concrete with 20%-60% substitution can attain a relatively high strength even though there is no treatment to recycled aggregate.(3)The ultimate compressive strength of alkali activated slag and fly ash-based recycled concrete with 100% substitution can reach 30MPa, which can be used for engineering practice without high early strength requirement.(4)Cracks on the surface of old mortar can make the interface a little bit denser. However, if there are too many cracks, it will further extend to the interface between old and new mortar and become the weak link of concrete structure.
出处
《重庆建筑》
2019年第3期47-50,共4页
Chongqing Architecture
基金
重庆大学国家级大学生创新训练项目(2017-10611-044)
关键词
碱矿渣混凝土
配合比设计
再生集料
绿色建材
alkali activated slag concrete
mix design
recycled aggregate
green building materials
