氧化镁活性、掺量以及温度对其砂浆限制膨胀率影响的研究

Effect of Activity, Mix Amount and Ambient Temperature of MgO on Limited Expansion Ratio

对不同温度20℃和60℃水养条件下,不同掺量4%和8%的两种不同活性的MgO样品MA(活性80s±20s)、MB(活性160s±20s)进行了胶砂限制膨胀率试验并分析,分别得出MgO活性、掺量和环境温度对其膨胀能的影响规律:MgO活性越高,前期反应越快,膨胀量越大,但后期反应速率越小,总膨胀量越小;MgO掺量越大,膨胀能越大;环境温度越高,MgO膨胀能越大,且MgO活性越低,对温度敏感性越高,温度变化时,其膨胀能变化越大。

Two kinds of active MgO samples,MA(active 80 s + 20s) and MB(active 160 S + 20s), are tested for mortar limited expansion ratio underdifferent temperature of 20℃ and 60 ℃ water curing and different mix amount of 4%and 8%. After analyzed, some conclusions that influence law of activity, mix amount and ambient temperature of MgO to its expansion energy were obtained. The higher the activity of MgO is, the faster the initial reaction is, the larger the expansion rate is, but the smaller the later reaction rate is, the smaller the total expansion is. The higher the mix amount of MgO is, the greater the expansion energy is. The higher the ambient temperature is, the greater the MgO expansion energy is, and the lower the MgO activity is, the higher the sensitivity to temperature is, and the greater the expansion energy is when the temperature changes.