低温环境对矿物掺合料水化活性的影响

Effect of low temperature environment on hydration activity of mineral admixtures

为了探究低温下矿物掺合料的水化活性,通过净浆抗压强度试验和XRD测试,对比研究了偏高岭土、粉煤灰和矿渣分别在常温[(20±2)℃]和低温(5℃)环境下的水化活性。结果表明:与常温情况相比,低温下,掺矿物掺合料试件中的Ca(OH)2衍射峰增强,Ca(OH)2主峰面积增大,说明低温在一定程度上抑制了胶凝体系的水化程度;低温对粉煤灰的早期水化活性降低最明显,其次是偏高岭土,对矿渣的早期水化活性影响相对较小;低温对偏高岭土的后期水化活性降低最明显,其次是粉煤灰,对矿渣的后期水化活性影响相对较小。

In order to investigate the hydration activity of mineral admixtures at low temperatures,the hydration activity of metakaolin,fly ash,and slag were compared and studied through compressive strength tests and XRD tests at room temperature[(20±2)℃]and low temperature(5℃)environments,respectively.The results show that compared with room temperature,the diffraction peak of Ca(OH)2 and the main peak area of Ca(OH)2 in the specimen with mineral admixtures are enhanced at low temperature,indicating that low temperature inhibits the hydration degree of the cementitious system to some extent.Low temperature has the most significant effect on the early hydration activity of fly ash,followed by metakaolin,which has a relatively small impact on the early hydration activity of slag.Low temperature has the most significant effect on the later hydration activity of metakaolin,followed by fly ash,which has a relatively small impact on the later hydration activity of slag.