地聚物胶结RAP混凝土微结构损伤机理研究
Failure mechanism of geopolymer cemented RAP concrete
刘富强 1郭伟东 2郭平 3曹天 2马庆伟 4白雪晴 5杨法勇 4刘冠宇 2陈华鑫6
作者信息
- 1. 河北大学 建筑工程学院,河北 保定 071002;西安公路研究院有限公司,西安 710065;长安大学 公路学院,西安 710064
- 2. 河北大学 建筑工程学院,河北 保定 071002
- 3. 西安公路研究院有限公司,西安 710065;陕西交控绿科环保有限公司,西安 710199
- 4. 西安公路研究院有限公司,西安 710065
- 5. 榆林学院 能源工程学院,陕西 榆林 719000
- 6. 长安大学 公路学院,西安 710064
- 折叠
摘要
为研究地聚物胶结 RAP混凝土的微观损伤及机理,选择矿渣、粉煤灰和助剂制备固废基胶凝材料(S-F Geopolymer),以废弃沥青混合料(reclaimed asphalt pavement,RAP)为骨料,用S-F Geopolymer胶结RAP制备出S-F Geopolymer胶结RAP混凝土.通过力学性能试验和SEM-EDS对S-F Geopolymer胶结RAP混凝土的力学性能和损伤微结构进行研究.研究结果表明:随着矿渣掺量的减小,S-F Geopolymer 的3、7、14、28 d抗压强度呈先增大后减小的变化趋势.粉煤灰和RAP掺量较大对S-F Geopolymer抗压强度不利.碱浓度对S-F Geopolymer后期抗压强度的影响比较显著,但前期对其影响不显著.模数改变对S-F Geopolymer的抗压强度影响显著.S-F Geopolymer在强度变化过程中存在C-S-H凝胶、N-A-S-H凝胶和C-A-S-H凝胶相,Na、Ca、Al、Si元素的分布较为均匀且有较多的重叠部分.新集料和S-F Geopolymer材料的粘结较好,掺有RAP的 S-F Geopolymer胶结 RAP混凝土破坏界面主要包括RAP集料内部、沥青-沥青粘结处和沥青-集料处破坏3 种形式.
Abstract
To study the microscopic damage and mechanism of geopolymer cement RAP concrete,S-F geopolymer is prepared by selecting slag,fly ash and auxiliars.Reclaimed asphalt pavement(RAP)is used as aggregate.S-F Geopolymer cemented RAP concrete is prepared from S-F Geopolymer cemented RAP.The mechanical properties and damaged microstructure of S-F Geopolymer cemented RAP concrete are studied by mechanical property test and SEM-EDS.Our results show the reduction of slag content leads to the change of compressive strength of S-F Geopolymer 3 d,7 d,14 d and 28 d,which increases first and then decreases.The high content of fly ash and RAP is unfavorable to S-F Geopolymer compressive strength.Alkali concentration exerts a marked influence on the increase of compressive strength of S-F Geopolymer in the later period,but has no significant effect in the earlier period.The modulus change greatly impacts the compressive strength of S-F Geopolymer.S-F Geopolymer contains C-S-H gels,N-A-S-H gels and C-A-S-H gels in the process of strength formation.The distribution of Na,Ca,Al and Si elements is relatively uniform and there are many overlapping parts.The new aggregate and S-F Geopolymer materials have a good bond.The damage interface of S-F Geopolymer cemented RAP concrete mixed with RAP mainly includes three forms of damage in RAP aggregate,asphalt-asphalt bond and asphalt-aggregate bond.
关键词
混凝土/废弃回收沥青混合料/地聚物/力学性能/损伤机理/微结构Key words
concrete/RAP/geopolymer/mechanical properties/failure mechanism/micro-structure引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据