Through the rapid chloride ion penetration test,the influence of fly ash and slag on chloride ion permeability and microstructure of concrete was studied.The results indicate that the addition of fly ash increases con...Through the rapid chloride ion penetration test,the influence of fly ash and slag on chloride ion permeability and microstructure of concrete was studied.The results indicate that the addition of fly ash increases concrete permeability at 28 days.With the slag content of 20% and 30%,the permeability of concrete at 28 days is reduced.The positive effect of slag is due to its relatively stronger pozzolanic reactive ability resulted in the most probable pore size and total porosity decreased.When the slag content reaches 40%,the concrete permeability showes the tendency ofincrease.展开更多
The effects of several mineral admixtures such as silica fume,granulated ground blast furnace slag and fly ash at different replacement ratio instead of Portland cement on the corrosion of steel reinforced concrete we...The effects of several mineral admixtures such as silica fume,granulated ground blast furnace slag and fly ash at different replacement ratio instead of Portland cement on the corrosion of steel reinforced concrete were investigated.By measuring the rebar anode polarization curve,permeability of concrete,mass loss of steel rebar and the amount of chloride ions and hydroxide in mortar,the corrosion resistance of steel embedded in fresh mortar incorporated of salt and different mineral admixtures were evaluated respectively.The results show that most mineral admixture can not improve corrosion resistance of concrete at early ages.However,in the long term the addition of mineral admixtures can decrease obviously the permeability of concrete and free chloride content in the pore solution of concrete as well as effectively improve the protection ability of passive film of steel rebar.展开更多
In this paper, we have studied the anti-rebar corrosion ability of high-strength concrete （HSC）, which were made by one or two mixed fly ash and slag. The different effects of fly ash and slag on concrete anti-rebar...In this paper, we have studied the anti-rebar corrosion ability of high-strength concrete （HSC）, which were made by one or two mixed fly ash and slag. The different effects of fly ash and slag on concrete anti-rebar corrosion ability were discussed in chloride ion-contaminated condition. The results indicate that the effects of slag on concrete anti-chloride ion penetration ability are more excellent than that of fly ash at the same content. When the content of fly ash is 10%, the corrosion-inhibition action is not obvious; when the content is higher than 25%, this effect is remarkable. Corrosion-inhibition action of slag is better than that of fly ash. Slag is not like fly ash that has obvious effect on anode curves Tafer slope, so its contribution to restraining rebar in concrete corrosion is the result of high concrete anti-chloride ion penetration ability and binding chloride ion. Their ＂superimposition effect＂ can be realized only at reasonable content and proportion condition.展开更多
基金Funded by the National Natural Science Foundation of China (No.50070819)
文摘Through the rapid chloride ion penetration test,the influence of fly ash and slag on chloride ion permeability and microstructure of concrete was studied.The results indicate that the addition of fly ash increases concrete permeability at 28 days.With the slag content of 20% and 30%,the permeability of concrete at 28 days is reduced.The positive effect of slag is due to its relatively stronger pozzolanic reactive ability resulted in the most probable pore size and total porosity decreased.When the slag content reaches 40%,the concrete permeability showes the tendency ofincrease.
基金Funded by the National Natural Science Foundation of China (No.50872127)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Heilongjiang
文摘The effects of several mineral admixtures such as silica fume,granulated ground blast furnace slag and fly ash at different replacement ratio instead of Portland cement on the corrosion of steel reinforced concrete were investigated.By measuring the rebar anode polarization curve,permeability of concrete,mass loss of steel rebar and the amount of chloride ions and hydroxide in mortar,the corrosion resistance of steel embedded in fresh mortar incorporated of salt and different mineral admixtures were evaluated respectively.The results show that most mineral admixture can not improve corrosion resistance of concrete at early ages.However,in the long term the addition of mineral admixtures can decrease obviously the permeability of concrete and free chloride content in the pore solution of concrete as well as effectively improve the protection ability of passive film of steel rebar.
基金Supported by the National Natural Science Foundation of China (50772084)
文摘In this paper, we have studied the anti-rebar corrosion ability of high-strength concrete （HSC）, which were made by one or two mixed fly ash and slag. The different effects of fly ash and slag on concrete anti-rebar corrosion ability were discussed in chloride ion-contaminated condition. The results indicate that the effects of slag on concrete anti-chloride ion penetration ability are more excellent than that of fly ash at the same content. When the content of fly ash is 10%, the corrosion-inhibition action is not obvious; when the content is higher than 25%, this effect is remarkable. Corrosion-inhibition action of slag is better than that of fly ash. Slag is not like fly ash that has obvious effect on anode curves Tafer slope, so its contribution to restraining rebar in concrete corrosion is the result of high concrete anti-chloride ion penetration ability and binding chloride ion. Their ＂superimposition effect＂ can be realized only at reasonable content and proportion condition.
