Open graded asphalt friction courses (OGAFCs) are specialty asphalt mixtures used to improve skid resistance and surface drainage. OGAFCs have additional benefits of reduced splash and spray, and lower tire–pavement interaction noise. Prolonged exposure to rainwater and load transfer through stone-on-stone contact in OGAFCs demands aggregates that are strong and hydrophobic. Rainwater acidity is expected to affect the aggregate–asphalt bond and thus moisture damage performance of OGAFC. This paper investigates the effect of rainwater acidity on moisture sensitivity of OGAFC mixtures with different aggregate types (natural aggregate, basic oxygen furnace (BOF) steel slag, and combinations of both) and modified binder types. For the first time, the present research reports the moisture damage potential of BOF OGAFC mixtures under different moisture conditioning environments created by varying the pH of contact water. With different combinations of BOF slag and natural aggregates (100:0, 25:75, 50:50, 75:25, and 0:100), and binders (polymer and crumb rubber modified), OGAFC mixtures were characterized for moisture damage through tensile strength ratio, wet Cantabro abrasion loss, and modified boiling water tests. Functional aspects of OGAFC mixtures subjected to moisture conditioning under different pH environments were also evaluated through permeability testing. Results showed that an acidic environment exacerbated the moisture damage, however, OGAFC mixtures containing BOF slag showed better performance than the control mixture (with natural aggregates only). Inclusion of BOF slag in OGAFC mixtures enhanced resistance to moisture damage under both pH environments. OGAFC mixes with 100% BOF slag content performed the best considering all moisture damage tests under both conditioning environments.

开放级沥青摩擦课程（OGAFC）是用于改善防滑性和地面排水的特种沥青混合物。OGAFC具有减少飞溅和喷雾以及降低轮胎与路面相互作用的噪音的其他好处。OGAFC中长时间接触雨水和通过石头对石头的接触进行负荷转移需要聚集体结实且疏水。雨水的酸度预计会影响骨料-沥青键，从而影响OGAFC的水分破坏性能。本文研究了雨水酸度对不同骨料类型（天然骨料，碱性氧气炉（BOF）钢渣，以及两者的组合）和改性粘结剂类型的OGAFC混合物的水分敏感性的影响。首次，本研究报告了在通过改变接触水的pH值而产生的不同水分调节环境下，BOF OGAFC混合物的水分破坏潜能。通过使用BOF炉渣和天然骨料（100：0、25：75、50：50、75：25和0：100）的不同组合以及粘合剂（改性的聚合物和碎橡胶），OGAFC混合物可通过以下方式对水分造成破坏：抗张强度比，湿式Cantabro磨损损失和改进的沸水测试。还通过渗透性测试评估了在不同pH环境下进行湿度调节的OGAFC混合物的功能方面。结果表明，酸性环境加剧了湿气的破坏，但是，含BOF炉渣的OGAFC混合物表现出比对照混合物更好的性能（仅含天然骨料）。在两种pH环境下，在OGAFC混合物中包含BOF炉渣均增强了抗潮性的能力。考虑到在两种调节环境下进行的所有湿气损害测试，OGAFC与100％BOF炉渣含量的混合料表现最佳。