A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Leaching tests on different mortars using accelerated electrochemical method
In designing radioactive waste repositories, it is necessary to predetermine the degree of concrete performance change due to leaching degradation. Leaching tests were carried out on different mortars using an electrochemical method. With this method, a potential gradient is applied across the specimen, which accelerates the dissolution of cement hydrate from mortar in contact with water. Tests were carried out using various sand/cement ratios, water/cement ratios, and pozzolanic admixture (blast-furnace slag (BF) and silica fume (SF)) replacement for a part of the cement to determine differences in the quality and quantity of cement hydrate. The amount of Ca2+ ions entering the water varied depending on the mix proportions. It decreased with sand content, but increased with water/cement ratio, and it varied with the kind of pozzolanic admixture and the replacement ratio. The pore volume of the degraded specimens increased as a result of cement hydrate dissolution. The water permeability of the mortar specimens increased by about one to two orders of magnitude due to leaching degradation. The compressive strength of the degraded mortar specimens decreased by 20% to 60%. There was good correspondence between each performance change and pore volume change due to leaching degradation. Pozzolanic admixture replacement for a part of the cement was very useful in achieving a durable concrete that resists leaching and shows a small loss of performance after leaching.
Leaching tests on different mortars using accelerated electrochemical method
In designing radioactive waste repositories, it is necessary to predetermine the degree of concrete performance change due to leaching degradation. Leaching tests were carried out on different mortars using an electrochemical method. With this method, a potential gradient is applied across the specimen, which accelerates the dissolution of cement hydrate from mortar in contact with water. Tests were carried out using various sand/cement ratios, water/cement ratios, and pozzolanic admixture (blast-furnace slag (BF) and silica fume (SF)) replacement for a part of the cement to determine differences in the quality and quantity of cement hydrate. The amount of Ca2+ ions entering the water varied depending on the mix proportions. It decreased with sand content, but increased with water/cement ratio, and it varied with the kind of pozzolanic admixture and the replacement ratio. The pore volume of the degraded specimens increased as a result of cement hydrate dissolution. The water permeability of the mortar specimens increased by about one to two orders of magnitude due to leaching degradation. The compressive strength of the degraded mortar specimens decreased by 20% to 60%. There was good correspondence between each performance change and pore volume change due to leaching degradation. Pozzolanic admixture replacement for a part of the cement was very useful in achieving a durable concrete that resists leaching and shows a small loss of performance after leaching.
Leaching tests on different mortars using accelerated electrochemical method
Saito, H. (author) / Deguchi, A. (author)
Cement and Concrete Research ; 30 ; 1815-1825
2000
11 Seiten, 8 Quellen
Article (Journal)
English
Leaching tests on different mortars using accelerated electrochemical method
| Online Contents | 2000
Leaching tests on different mortars using accelerated electrochemical method
| British Library Online Contents | 2000
Deterioration of Different Mortars Using Accelerated Electrochemical Test
| British Library Online Contents | 1997