QXRD方法定量分析水泥浆体中MgO的水化程度

Application of QXRD to Determine the Hydration Degree of MgO Contained in Cement Paste

采用QXRD法(Quantitative X-ray diffraction)对掺两种MgO膨胀剂水泥浆体中主要水化产物进行定量分析,以ZnO为内标物计算水化产物中非晶相的含量,并计算养护不同龄期水泥浆体中MgO的水化程度。结果表明:40 ℃水养条件下,60 d时掺高活性MgO水泥浆体中MgO基本水化完全,而掺低活性MgO水泥浆体中MgO还有15%未水化;水泥浆体中MgO在早期具有较快的水化速率,后期水化速率变缓;相同龄期内,高活性MgO具有较快的水化速率,水化程度较高,但产生的膨胀量小于低活性MgO产生的膨胀量。

Quantitative X-ray diffraction (QXRD) was applied to quantify the mineral phases in hydrated cement pastes, ZnOwas used as an internal standard to determine the amorphous phase content, and the hydration degree of MgO contained in cement pastes was calculated in different ages. The results show that cured in 40 ℃ water for 60 d, MgO contained in cement pastes with M1 almost hydrated completely, while 15% of MgO contained in cement pastes with M2 has not hydrated. MgO contained in cement pastes has a faster hydration rate at the early age, with the increase of curing age, the hydration rate slows down. At the same age, MgO with higher activity has faster hydration rate and lager hydration degree, but smaller expansion than that of MgO with low activity.