Ann K Y, Moon H Y, Kim Y B, Ryou J
School of Civil and Environmental Engineering, Yonsei University, Seoul, Republic of Korea.
Waste Manag. 2008;28(6):993-9. doi: 10.1016/j.wasman.2007.03.003. Epub 2007 May 1.
In this study, pulverized fuel ash (PFA) and ground granulated blast furnace slag (GGBS) were used to compensate for the loss of strength and durability of concrete containing recycled aggregate. As a result, 30% PFA and 65% GGBS concretes increased the compressive strength to the level of control specimens cast with natural granite gravel, but the tensile strength was still lowered at 28 days. Replacement with PFA and GGBS was effective in raising the resistance to chloride ion penetrability into the concrete body, measured by a rapid chloride ion penetration test based on ASTM C 1202-91. It was found that the corrosion rate of 30% PFA and 65% GGBS concretes was kept at a lower level after corrosion initiation, compared to the control specimens, presumably due to the restriction of oxygen and water access. However, it was less effective in increasing the chloride threshold level for steel corrosion. Hence, it is expected that the corrosion time for 30% PFA and 65% GGBS concrete containing recycled aggregate mostly equates to the corrosion-free life of control specimens.
在本研究中，使用了粉煤灰（PFA）和磨细粒化高炉矿渣（GGBS）来弥补含再生骨料混凝土强度和耐久性的损失。结果表明，30%粉煤灰和65%矿渣混凝土的抗压强度提高到了用天然花岗岩碎石浇筑的对照试件的水平，但28天时的抗拉强度仍有所降低。用粉煤灰和矿渣替代有效地提高了混凝土对氯离子渗透的抵抗能力，这是通过基于ASTM C 1202 - 91的快速氯离子渗透试验来测量的。研究发现，与对照试件相比，30%粉煤灰和65%矿渣混凝土在腐蚀开始后的腐蚀速率保持在较低水平，这可能是由于氧气和水的进入受到了限制。然而，它在提高钢筋腐蚀的氯离子阈值水平方面效果较差。因此，预计含再生骨料的30%粉煤灰和65%矿渣混凝土的腐蚀时间大多与对照试件的无腐蚀寿命相当。
