物理化学强化对再生混凝土抗碳化性能的影响

摘要

T he waste concrete is simply crushed to Ⅱ class recycled coarse aggregate,firstly reshaped to I class-to-be recycled coarse aggregate in physical strengthening and tw ice reshaped to I class recycled coarse aggregate in physical strengthening. T hree kinds of recycled coarse aggregate are soaked in organic silicon w aterproof agent of concentration 6% for 24 h chemical treatment,making three kinds of recycled coarse aggregate of physical and chemical enhancement. T he influence on carbonation was studied by the replacement of natural aggregated,and the substitution rate of recycled coarse aggregate of physical and chemical enhancement was 0,50% and 100%, respectively. T he results show that the chemical enhancement and twice reshaped recycled coarse aggregate concrete has the best carbonation of recycled coarse aggregate concrete,then the chemical enhancement and firstly reshaped recycled coarse aggregate concrete,and the worst is the chemical enhancement and simply crushed recycled coarse aggregate concrete. T he carbonation performance of the above three types of concrete is better than that of ordinary concrete. W ith the increase of the substitution rate,carbonation depth of three types of recycled coarse aggregate of physical and chemical enhancement reduces.%将废弃混凝土经简单破碎、一次颗粒整形和二次颗粒整形后分别制得Ⅱ类再生粗骨料、准Ⅰ类再生粗骨料和Ⅰ类再生粗骨料，并将三种再生粗骨料在浓度6%的有机硅烷防水剂中化学浸渍24 h，得到三种品质的物理化学强化再生粗骨料。研究三种品质的物理化学强化再生粗骨料分别以取代率0，50%，100%取代天然骨料后对再生混凝土抗碳化性能的影响。结果显示：化学强化二次颗粒整形再生粗骨料混凝土的抗碳化性能最好，化学强化一次颗粒整形再生粗骨料混凝土的抗碳化性能次之，化学强化简单破碎再生粗骨料混凝土的抗碳化性能最差，但三者均优于普通混凝土；三种再生混凝土的碳化深度均随着再生粗骨料取代率的增大而减小。