硬化水泥石热膨胀性能的调节及其机理研究

研究了水灰比和矿物掺合料对硬化水泥石在20℃～85℃热膨胀性能的影响,并进行了机理分析。研究结果表明：水泥石的热膨胀率和热膨胀系数随着水灰比的增大而减小;粉煤灰和矿粉均可有效降低水泥石的热膨胀性能,其降低程度随掺量的增大而增大;当矿物掺合料掺量相同时,粉煤灰水泥石的热膨胀率及热膨胀系数略低于矿粉水泥石。通过观察水泥石微观形貌和测定水泥石孔隙率等方法,对硬化水泥石的热膨胀性能进行机理分析。

Adjustment of Thermal Expansion Behaviour of Hardened Cement Paste and Its Mechanisms

The effect and mechanism of water-cement ratio and mineral admixtures on thermal expansion of hardened cement pastes from 20 to 85 ℃ were investigated. The results show that thermal expansion rate and coefficient of thermal expansion of hardened cement pastes decreases when the water-cement ratio increases. Thermal expansion properties of hardened cement paste were reduced after fly ash and blast furnace slag was added. The thermal expansion rate and coefficient of thermal expansion of hardened cement pastes with fly ash was slightly lower than those of hardened cement pastes with slag with the same mixing amount of mineral admixtures. The mechanism of thermal expansion properties of hardened cement paste was also researched with observing the microstructure and testing the porosity of hardened cement pastes.