ISISE, Department of Civil Engineering, University of Minho, 4800-058 Guimarães, Portugal.
Department of Civil Engineering, University of Minho, 4800-058 Guimarães, Portugal.
Molecules. 2020 May 29;25(11):2533. doi: 10.3390/molecules25112533.
The influence of suction on the mechanical behaviour of unsaturated chemically stabilised soils is still mostly unknown and unquantified. This is also motivated by the difficulties associated with the experimental procedure required to fully characterise the unsaturated response of the soil, including its direct influence on traditional strength tests. The present paper presents the soil water retention curves obtained for a Portuguese soil before and after being stabilised with Portland cement (OPC) and an alkali-activated cement (AAC). Saturated undrained triaxial tests were also performed for the same curing conditions (0, 28, and 90 days). Previous attempts to characterise the retention curve of soils stabilised with AAC are unknown, and the results showed that the pore volume structure is already formed after 28 days, prior to the full development of the gel matrix responsible for the strength increase between 28 and 90 days. The curve changed after stabilisation, and with each binder, as the OPC presented a higher air-entry value and a narrower suction range compared to the AAC solution. The significant differences between the curves obtained from each binder suggest the future development of a methodology to assess the quality of the AAC stabilisation.
吸力对非饱和化学稳定土力学行为的影响仍然知之甚少，也无法量化。这也是由于需要完全描述土壤的非饱和响应所涉及的实验程序的困难所致，包括其对传统强度测试的直接影响。本文介绍了一种葡萄牙土在使用波特兰水泥（OPC）和碱激活水泥（AAC）稳定前后获得的土壤水分保持曲线。对于相同的养护条件（0、28 和 90 天），还进行了饱和不排水三轴试验。以前尝试描述用 AAC 稳定的土壤的保持曲线是未知的，结果表明，在负责 28 至 90 天之间强度增加的凝胶基质完全发展之前，28 天后已经形成了孔隙体积结构。曲线在稳定后发生了变化，并且与每种粘结剂一样，与 AAC 溶液相比，OPC 具有更高的进气值和更窄的吸力范围。从每种粘结剂获得的曲线之间存在显著差异，这表明未来将开发一种方法来评估 AAC 稳定的质量。
