本工作以3%质量浓度的NaCl溶液为介质,进行混凝土抗冻性试验,通过超声波波速损失率(C_(n))、质量剥蚀量(M_(B))和溶液吸入率(W_(S))三种指标研究了CTF(Coal tar fuel)增效剂对混凝土抗冻性能的影响。同时,深入剖析了CTF增效剂对混凝土...本工作以3%质量浓度的NaCl溶液为介质,进行混凝土抗冻性试验,通过超声波波速损失率(C_(n))、质量剥蚀量(M_(B))和溶液吸入率(W_(S))三种指标研究了CTF(Coal tar fuel)增效剂对混凝土抗冻性能的影响。同时,深入剖析了CTF增效剂对混凝土内部气孔结构的影响,并基于气孔分形模型,建立了分形维数(D)与超声波波速损失率(C_(n))的关系。结果表明:CTF增效剂能有效提升混凝土的抗冻性能,且当掺量为0.7%时提升效果最为显著。与普通混凝土相比,降低10%的水泥用量并掺加0.7%的CTF增效剂时,冻融循环100次后,混凝土超声波波速损失率(C_(n))较小,且质量剥蚀量(M_(B))降低了12.51%。此外,NaCl溶液吸入率(W_(S))降低了0.83%,内部直径规格小于100μm的气孔个数增加了180%,大于100μm的气孔个数减少了18.18%。展开更多
Municipal solid waste incineration tailings were used as lightweight aggregate(MSWIT-LA)in the preparation of specified density concrete to study the effects on compressive strength,axial compressive strength,flexural...Municipal solid waste incineration tailings were used as lightweight aggregate(MSWIT-LA)in the preparation of specified density concrete to study the effects on compressive strength,axial compressive strength,flexural strength,microhardness,total number of pores,pore area,and pore spacing.The results showed that the internal curing and morphological effects induced by an appropriate quantity of MSWIT-LA improved the compressive response of specified density concrete specimens,whereas an excessive quantity of MSWIT-LA significantly reduced their mechanical properties.An analysis of pore structure indicated that the addition of MSWIT-LA increased the total quantity of pores and promoted cement hydration,resulting in a denser microstructure than that of ordinary concrete.The results of a principal component analysis showed that the mechanical response of specified density concrete prepared with 25%MSWIT-LA was superior to that of an equivalent ordinary concrete.It was therefore concluded that MSWIT-LA can be feasibly applied to achieve excellent specified density concrete properties while utilising municipal solid waste incineration tailings to protect the environment and alleviate shortages of sand and gravel resources.展开更多
文摘本工作以3%质量浓度的NaCl溶液为介质,进行混凝土抗冻性试验,通过超声波波速损失率(C_(n))、质量剥蚀量(M_(B))和溶液吸入率(W_(S))三种指标研究了CTF(Coal tar fuel)增效剂对混凝土抗冻性能的影响。同时,深入剖析了CTF增效剂对混凝土内部气孔结构的影响,并基于气孔分形模型,建立了分形维数(D)与超声波波速损失率(C_(n))的关系。结果表明:CTF增效剂能有效提升混凝土的抗冻性能,且当掺量为0.7%时提升效果最为显著。与普通混凝土相比,降低10%的水泥用量并掺加0.7%的CTF增效剂时,冻融循环100次后,混凝土超声波波速损失率(C_(n))较小,且质量剥蚀量(M_(B))降低了12.51%。此外,NaCl溶液吸入率(W_(S))降低了0.83%,内部直径规格小于100μm的气孔个数增加了180%,大于100μm的气孔个数减少了18.18%。
基金Funded by the National Natural Science Foundation of China(Nos.U21A20150,52208249,51878153,52108219,52008196,52178216)Research and Demonstration of Key Technologies of Green and Smart Highways in Gansu Province(No.21ZD3GA002)+1 种基金Gansu Provincial Natural Science Foundation(No.23JRRA799)Key Projects of Chongqing Science and Technology Bureau(No.2021jscx-jbgs0029)。
文摘Municipal solid waste incineration tailings were used as lightweight aggregate(MSWIT-LA)in the preparation of specified density concrete to study the effects on compressive strength,axial compressive strength,flexural strength,microhardness,total number of pores,pore area,and pore spacing.The results showed that the internal curing and morphological effects induced by an appropriate quantity of MSWIT-LA improved the compressive response of specified density concrete specimens,whereas an excessive quantity of MSWIT-LA significantly reduced their mechanical properties.An analysis of pore structure indicated that the addition of MSWIT-LA increased the total quantity of pores and promoted cement hydration,resulting in a denser microstructure than that of ordinary concrete.The results of a principal component analysis showed that the mechanical response of specified density concrete prepared with 25%MSWIT-LA was superior to that of an equivalent ordinary concrete.It was therefore concluded that MSWIT-LA can be feasibly applied to achieve excellent specified density concrete properties while utilising municipal solid waste incineration tailings to protect the environment and alleviate shortages of sand and gravel resources.
