The early stage hydration mechanism of cellulose ether modified thin layer cement pastes was studied, using brick as the matrix. Samples of 6 h, 24 h, and 3 d and 7 d hydration time were analyzed to study the hydratio...The early stage hydration mechanism of cellulose ether modified thin layer cement pastes was studied, using brick as the matrix. Samples of 6 h, 24 h, and 3 d and 7 d hydration time were analyzed to study the hydration law on the surface of high water-absorbing matrix. Hydration products were qualitatively and semi-quantitatively analyzed using XRD, TG-DSC-DTG, FTIR and SEM. The experimental results show that there is no enough water for 2 mm thick cement pastes to hydrate, because of rapid water absorption of matrix. Trace amounts of Ca （OH）2 was detected after three days hydration. With the prolongation of hydration time, the category and concentration of hydration products do not change. Compared with 2 mm thick cement pastes, 6 mm thick cement pastes and 10 mm thick cement pastes have lower dehydration rate and water loss. The humidity field of the cement paste show different changes within the same time. 6 mm thick cement paste and 10 mm thick cement pastes have longer time and more water to hydrate. Ca（OH）2 and ettringite were detected after 6 hours hydration and the concentrations of hydration products increased from 24 hours to 7 days.展开更多
主要研究了低品位二、三级硅藻土与纤维素醚协同作用对薄灰缝砌筑砂浆保水性能的影响。试验结果表明,经活化处理的硅藻土能显著提高砂浆的保水性以及力学性能,经10 min机械活化、2 h 600℃热活化处理的硅藻土薄灰缝砌筑砂浆保水率最高可...主要研究了低品位二、三级硅藻土与纤维素醚协同作用对薄灰缝砌筑砂浆保水性能的影响。试验结果表明,经活化处理的硅藻土能显著提高砂浆的保水性以及力学性能,经10 min机械活化、2 h 600℃热活化处理的硅藻土薄灰缝砌筑砂浆保水率最高可达95.7%,较空白组提高了22%;HPMC能提高砂浆的保水性,但明显降低砂浆的力学性能,掺量为0.27%时,砂浆的保水率达到最优99.4%;当硅藻土与纤维素醚混掺时,保水率≥99%,能显著降低纤维素醚用量,有较好的经济与环保价值。展开更多
基金Funded by the Youth Fund of National Natural Science Foundation of China (50902107)
文摘The early stage hydration mechanism of cellulose ether modified thin layer cement pastes was studied, using brick as the matrix. Samples of 6 h, 24 h, and 3 d and 7 d hydration time were analyzed to study the hydration law on the surface of high water-absorbing matrix. Hydration products were qualitatively and semi-quantitatively analyzed using XRD, TG-DSC-DTG, FTIR and SEM. The experimental results show that there is no enough water for 2 mm thick cement pastes to hydrate, because of rapid water absorption of matrix. Trace amounts of Ca （OH）2 was detected after three days hydration. With the prolongation of hydration time, the category and concentration of hydration products do not change. Compared with 2 mm thick cement pastes, 6 mm thick cement pastes and 10 mm thick cement pastes have lower dehydration rate and water loss. The humidity field of the cement paste show different changes within the same time. 6 mm thick cement paste and 10 mm thick cement pastes have longer time and more water to hydrate. Ca（OH）2 and ettringite were detected after 6 hours hydration and the concentrations of hydration products increased from 24 hours to 7 days.
文摘主要研究了低品位二、三级硅藻土与纤维素醚协同作用对薄灰缝砌筑砂浆保水性能的影响。试验结果表明,经活化处理的硅藻土能显著提高砂浆的保水性以及力学性能,经10 min机械活化、2 h 600℃热活化处理的硅藻土薄灰缝砌筑砂浆保水率最高可达95.7%,较空白组提高了22%;HPMC能提高砂浆的保水性,但明显降低砂浆的力学性能,掺量为0.27%时,砂浆的保水率达到最优99.4%;当硅藻土与纤维素醚混掺时,保水率≥99%,能显著降低纤维素醚用量,有较好的经济与环保价值。
