ABSTRACT

Oyster farming annually generates millions of empty hard seashells as by-product waste in municipal landfills worldwide. Using this waste as fine and coarse aggregates as construction materials offers a low energy consumption alternative to recycling and mining of virgin materials. This research explores the use of seashell as a cost-effective replacement of virgin fine aggregate in hot mix asphalt (HMA). The properties of HMA mixtures with seashells were investigated using indirect tensile strength, permanent deformation and moisture susceptibility tests; tests used in standard practice in Perú. The results indicate that seashells can be used as fine aggregate improving the indirect tensile strength and the permanent deformation of HMA. Seashells in the asphalt mixture reduced moisture susceptibility compared to conventional HMA, with an increase of tensile strength ratio (TSR) values of 22–262%, a very important finding since with areas of Perú recently experiencing severe flooding events where seashells have the potential to reduce stripping. The laboratory study also showed that seashell sizes of 300–2.36 mm yielded highest TSR values. Replacement of fine aggregate with seashells increases total HMA cost by about 2.9–4.6%.

摘要

牡蛎养殖每年在全球范围的市政垃圾填埋场中产生数百万个空的硬贝壳作为副产品废物。使用这些废料作为建筑材料的细骨料和粗骨料，可以替代原始材料的回收和开采，从而降低能耗。这项研究探索了使用贝壳作为热拌沥青（HMA）中原始细骨料的经济有效替代品。使用间接拉伸强度，永久变形和湿气敏感性试验研究了HMA混合贝壳的性能。秘鲁标准实践中使用的测试。结果表明，贝壳可用作细骨料，可改善HMA的间接拉伸强度和永久变形。与传统的HMA相比，沥青混合料中的贝壳降低了水分敏感性，拉伸强度比（TSR）值提高了22–262％，这是一个非常重要的发现，因为秘鲁最近遭受严重洪灾的地区，贝壳具有减少剥落的潜力。实验室研究还表明，贝壳尺寸为300–2.36 mm的TSR值最高。用贝壳代替细骨料会增加HMA总成本约2.9–4.6％。