摘要
围绕着含有两种矿物掺合料混凝土(粉煤灰和矿渣)在碳化和静力荷载耦合作用下的劣化过程和机理,揭示了掺合料对混凝土碳化深度、抗折强度的影响规律,同时分析了不同弯曲荷载应力对混凝土碳化深度的影响,并应用多物理场耦合有限元软件COMSOL Multiphysics进行求解。研究结果表明:对于单掺粉煤灰的试件,其抗碳化性能随着掺量的增加而降低;而对于单掺矿渣的试件,矿渣含量为10%时,其抗碳化性能最好,然而当矿渣含量达到40%时,其抗碳化能力大幅降低;对于双掺试件,在任一掺合料取代率达到40%时,抗碳化能力有着显著的降低;在一定应力范围内,弯曲拉应力能显著提高混凝土的碳化深度,而弯曲压应力改善了混凝土的抗碳化能力;COMSOL模拟显示碳化深度试验值和模拟值较为吻合。
It focuses on the mechanism of deterioration of concrete containing mineral admixtures （FA and BFS） under the coupling ac- tion of carbonation and static load.The effects of different types （contents） of admixtures on concrete carbonation depth, flexural strength are investigated respectively.Meanwhile,the effect of bending load with different levels and types on carbonation depth is investigated.The mod- el is solved by application of multi-physics sottware COMSOL Multiphysics.The results show that carbonation resistance of fly ash concrete is decreased with the increase of FA contents,while the carbonation resistance of BFS concrete is increased to the point where the value of BFS content is 0.1,then decreased with the increase of BFS content,when the value of BFS content is above 0.4,the carbonation resistance of BFS concrete decreased seriously.For the concrete with blended admixtures, carbonation resistance will be very low when the value of any single admixture content reaches to 0.4.Within a certain range,bending tensile stress can significantly increase the carbonation depth, while the carbonation resistance of concrete increase due to the bending compressive stress improves the pore structure ofconcrete.COMSOL sim- ulation shows that the experimental data of the carbonation depth and simulated values are in good agreement.
出处
《混凝土》
CAS
北大核心
2017年第10期15-19,共5页
Concrete
基金
国家自然科学基金(51308290)
教育部博士点基金(20133221120004)
江苏省高校自然科学研究重大项目(14KJA560001)
江苏省产学研联合创新资金-前瞻性联合研究项目(BY2014005-05)
