再生细骨料强化对混凝土性能的影响

Influence of recycled fine aggregate reinforced in properties of concrete

分别采用颗粒整形物理强化方法、有机硅防水剂化学强化方法和物理-化学复合强化方法对简单破碎再生细骨料进行强化处理后制备再生混凝土,重点研究强化处理前后再生细骨料对混凝土力学性能和耐久性能的影响。研究表明,经过强化处理的再生细骨料混凝土的抗压强度、抗渗透性能和抗碳化性能均有显著的提高,其中在二次物理强化处理后再生混凝土的抗压强度达到最高值,接近于天然河砂混凝土的抗压强度,在二次物理强化和化学浸渍复合强化处理后再生混凝土的氯离子扩散系数减小到3.98×10-12m2s,在二次物理强化处理后其3、7、14、28 d的碳化深度分别较天然河砂混凝土仅增加0.6、0.3、0.2、0.3 mm。

This thesis adopted the physical strengthening method of particle plastic and the chemical strengthening method of organosili-con water-repellent and physical-chemical compound strengthening method to strengthen the simple crushing recycled fine aggregate to prepare the recycled concrete,and it focused on the influence of the recycled fine aggregate before and after strengthening treatment on the mechanical properties and durability of concrete. The research shows that the compressive strength,penetration resistance and car-bonation resistance of recycled fine aggregate concrete through strengthening processing are improved significantly. And the compressive strength of recycled concrete after the secondary physical strengthen treatment reaches the highest value,close to the compressive strength of the concrete in natural river sand,and also,the chloride ion diffusion coefficient of recycled concrete after the secondary physical-chemical compound strengthening treatment decreases to 3.98 × 10 -12 m2 ？s,besides,compared with the concrete in natural river sand,the carbonation depth of recycled concrete after the secondary physical strengthen treatment of the 3,7,14,28 d were in-creased only in 0.6,0.3,0.2,0.3 mm.