This paper studies the effectiveness of alkaline activation of low-calcium fly ash on the improvement of residual granitic soils to be used on rammed-earth construction. Different liquid:solid ratios, alkali concentrations and Na2O : ash ratios were tested. Effect of calcium hidroxide, sodium chloride and concrete superplasticiser is also reported. Compressive strength up to 7 days at 60ºC was determined. Results show that, in terms of mechanical strength, there is an optimum value for the activator:solids ratio and the alkali concentration, and that a decrease in the Na2O:ash ratio results in strength increase. No improvement was observed with the sodium chloride or the superplasticiser, while the calcium produced only a short term increase in strength. SEM/EDS analysis were used to analyse microstructural development, showing that strength is fairly related to the Si:Al and Na:Si ratios.
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机译:本文研究了低钙粉煤灰的碱活化作用对改良夯土施工中残留的花岗岩土壤的有效性。测试了不同的液体:固体比率,碱浓度和Na2O:灰分比率。还报道了氢氧化钙,氯化钠和混凝土高效减水剂的作用。确定了在60ºC下长达7天的抗压强度。结果表明,就机械强度而言,活化剂:固含量比和碱浓度存在一个最佳值,而Na2O:灰分比的降低导致强度增加。氯化钠或高效减水剂没有发现改善,而钙的强度只是短期增加。 SEM / EDS分析被用来分析微观结构的发展,表明强度与Si:Al和Na:Si的比例相当相关。
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