Micro-mechanisms and compressive strength of Geopolymer-Portland cementitious system under various curing temperatures
Micro-mechanisms and compressive strength of Geopolymer-Portland cementitious system under various curing temperatures
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DOI：
10.1016/j.matchemphys.2016.05.069
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发表时间：
2016-09
影响因子：
4.6
通讯作者：
T. Suwan;M. Fan;N. Braimah
中科院分区：
文献类型：
--
作者：
T. Suwan;M. Fan;N. Braimah
低钙粉煤灰基地质聚合物膏体（GP）的优异强度只有在高温固化（60-90 °C）下才能实现。为了在环境固化温度（20 ± 2 °C）下实现合理的强度，已经研究了将OPC包含到GP（GeoPC系统）中以加速（C，N）-A-S-H形成以实现早期强度发展。本文介绍了GeoPC在不同固化温度（10-70 °C）下的微观机制和抗压强度的发展，以更好地理解和确定OPC和GP对GeoPC系统的综合影响。结果表明，随着固化温度的升高，GeoPC体系的强度趋于接近GP。但在中温（20-50 °C）固化条件下，由于固化过程中C-（A）-S-H和N-A-S-H凝胶的额外析出或OPC同时产生内热，以及其微观结构和机理，GeoPC体系的强度明显高于GP体系。可以得出结论，当施加相同水平的中等固化温度时，GeoPC可以实现比GP更大的强度，从而导致更少的热固化能量消耗。最佳固化温度范围为30-40 °C，这在整个夏季的炎热环境中都可以找到。因此，作为自固化地质聚合物的一部分，GeoPC的生产可以扩展到更方便的实际工作，并在建筑行业商业化。
The excellent strength of low calcium fly ash-based geopolymer paste (GP) can only be attained when high heat curing (60–90 °C) is applied. To achieve reasonable strength in ambient curing temperature (20 ± 2 °C), an inclusion of OPC to GP (GeoPC system), has been studied to accelerate (C,N)-A-S-H formation to achieve an early strength development. This paper presents the micro-mechanisms and hence development of compressive strength of GeoPC under various curing temperatures (10–70 °C) to develop a better understanding and to determine the combined effect of OPC and GP on the GeoPC systems. The results exhibited that the strength of GeoPC system tended to be similar to the GP as strength was increased when the curing temperature increased. However, with the same level of curing in a moderate temperature (20–50 °C), the strength of GeoPC system was evidently higher than that of GP due to an extra precipitation of both C-(A)-S-H and N-A-S-H gel or after internal heat from OPC simultaneously during curing process, as well as its microstructures and mechanisms. It may be concluded that the GeoPC could achieve greater strength than that of GP when the same level of moderate curing temperature was applied, leading to less heat-cured energy consumption. The optimum curing was in a mild temperature range of 30–40 °C, which could be found in hot environment area throughout summer time. The production of GeoPC, a part of self-cured geopolymer, could therefore be extended to be more convenient in practical work and be commercialised in construction industry.