N-2000 is an admixture for concrete, with a low slump loss, high range water-reducing ratio and long-time retarding. The N-2000 is made up of naphthalene-sulfonic-maldehyde polycondensation (NSMP) and ATMP. Its charac...N-2000 is an admixture for concrete, with a low slump loss, high range water-reducing ratio and long-time retarding. The N-2000 is made up of naphthalene-sulfonic-maldehyde polycondensation (NSMP) and ATMP. Its characteristic results from the synergistic effects of NSMP and ATMP. The results show that when 0.7%-1.2% of N-2000 is added to concrete (by mass of cement), the water reducing ratio is up to 20%-30%, and the slump of fresh concrete can be retained for 2 hours without significant loss. N-2000 can not only improve the workability of fresh concrete but also increase the strength of the hardened concrete, especially early strength. It is also proved to have a good compatibility with various cements.展开更多
An ability of aluminum-bearing substances-amorphous aluminum hydroxide, aluminum sulphate and basic aluminum sulphate to mitigate alkali-silica reactions in Portland cement mortars has been studied. At equivalent dosa...An ability of aluminum-bearing substances-amorphous aluminum hydroxide, aluminum sulphate and basic aluminum sulphate to mitigate alkali-silica reactions in Portland cement mortars has been studied. At equivalent dosages in terms of Al2O3, these substances are ranged in the following order in respect of inhibiting effect: Al(OH)1.78(SO4)0.61 ≥ Al2(SO4)3 > Al(OH)3. It is found that the plasticizing agents of the main types used in cement compositions have no influence on the inhibiting effect of aluminum-bearing admixtures. To control the setting time of cement paste, iron(II) sulphate may be used for partial substitution of Al2SO4·18H2O, and this operation is not influence on the results of ASR expansion test.展开更多
基金Key Science and Technology Development Fund Project of Hubei Province.China(No.941PO106).
文摘N-2000 is an admixture for concrete, with a low slump loss, high range water-reducing ratio and long-time retarding. The N-2000 is made up of naphthalene-sulfonic-maldehyde polycondensation (NSMP) and ATMP. Its characteristic results from the synergistic effects of NSMP and ATMP. The results show that when 0.7%-1.2% of N-2000 is added to concrete (by mass of cement), the water reducing ratio is up to 20%-30%, and the slump of fresh concrete can be retained for 2 hours without significant loss. N-2000 can not only improve the workability of fresh concrete but also increase the strength of the hardened concrete, especially early strength. It is also proved to have a good compatibility with various cements.
文摘An ability of aluminum-bearing substances-amorphous aluminum hydroxide, aluminum sulphate and basic aluminum sulphate to mitigate alkali-silica reactions in Portland cement mortars has been studied. At equivalent dosages in terms of Al2O3, these substances are ranged in the following order in respect of inhibiting effect: Al(OH)1.78(SO4)0.61 ≥ Al2(SO4)3 > Al(OH)3. It is found that the plasticizing agents of the main types used in cement compositions have no influence on the inhibiting effect of aluminum-bearing admixtures. To control the setting time of cement paste, iron(II) sulphate may be used for partial substitution of Al2SO4·18H2O, and this operation is not influence on the results of ASR expansion test.
