再生粗骨料取代率对植生型透水混凝土性能的影响

Influence of Recycled Coarse Aggregate Replacement on Properties of Vegetation Type Permeable Concrete

生态型透水混凝土是实现海绵城市构想的材料基础。再生混凝土粗骨料自身存在吸水率高、强度略低于同类型天然骨料的弱点,但将其应用于植生型透水混凝土则可以避免这些弱点的不利影响并有利于建筑垃圾的再生利用。本文研究了不同的再生粗骨料取代率对植生型透水混凝土抗压强度、孔隙率和植生适应性的影响。结果表明:再生粗骨料取代量为25%时,植生型透水混凝土28d抗压强度略有提高;100%取代时强度降低不明显;但中高取代量时,由于不同类型骨料形成的混凝土骨架及其节点界面削弱,导致强度有所降低。再生粗骨料取代率对混凝土的孔隙率没有明显影响,植物试种试验表明其植生适应性未受影响。与插捣成型工艺相比较,振动成型工艺容易出现沉浆现象,不利于植物生长。

Vegetation type permeable concrete is the material foundation to realize sponge city vision. Compared with natural aggregate,recycled concrete coarse aggregate has the weaknesses such as higher water absorption,and lower compressive strength. But if the recycled aggregate was applied to vegetation type permeable concrete, the adverse impact can be avoided and benefit the recycling of construction waste. In this paper, the effect on the different recycled coarse aggregate replacement ratio of vegetation type permeable concrete compressive strength, porosity and vegetative adaptability were experimental studied. The results showed that the amount of recycled coarse aggregate was 25%, the vegetation type permeable concrete 28d compressive strength increased slightly. The decrease of strength is not obvious while the replaced ratio is 100%. When the replace quantity is high , because of different types aggregate formation concrete skeleton and weak node interface, it lead to strength decrease. But the recycled coarse aggregate replacement ratio had no significant effect on the porosity and the vegetative flexibility unaffected of eco-porous concrete. Compared with inserted vibrating molding process, vibration molding process prone to cement paste settlement phenomenon, is not conducive to the growth of plants.