摘要
研究在饱和状态、反复干湿循环和自然蒸发3种情况下常用屋顶绿化基质材料陶粒、草炭和保水剂的保水性能。通过抽真空饱和试验得到基质材料的蓄水性能，试验发现基质材料混合后实测饱和含水量大于理论推算值，分析了导致材料混合使得蓄水性能大幅提高的原因。采用反复干燥吸水试验证明陶粒和草炭具有良好的热稳定性，而保水剂在较高温度烘干时主分子链易断裂，反复吸水和烘干后其保水性能大幅降低。常温常压蒸发试验表明在含水量较高时，三者蒸发速率与自由水面蒸发的相当，随着含水量降低，保水性能越差的基质材料蒸发速率降低越快，合理添加保水剂能有效改善基质材料保水性能。
Abstract
The water retention capacities of commonly used roof greening matrices ,concluding ceramsite ,peat and super absorbent polymer ,under fully saturated ,cyclic wetting‐drying and natural evaporation conditions were studied .The saturated water retention capacity of matrices were obtained by vacuum saturated test .It showed that the fully measured saturated degree of saturation of mixed matrix was greater than that calculated by the combination of all components .The reason which increases the water contents to porous skeleton was analysed .In cyclic wetting‐drying tests ,the water retention capacities of ceramsite and peat were almost unchanged .However , due to the main molecular chain broken under drying in relatively high temperature ,the water retention capacity decreased rapidly after several wetting‐drying cycles . In natural evaporation tests , the evaporation rates of ceramsite ,peat , super absorbent polymer and free water were almost identical in the condition of high water content .As the water content decreasing ,the evaporation rate of the matrix which had lower water retention capacities decreases faster .The matrix with a reasonable proportion of super absorbent polymer can remarkably improved its water retention capacity .
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维普
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