ABSTRACT

High rate of construction and demolition waste materials results in a large amount of stockpiled waste materials. Pavement industry is now considering a sustainable approach for asphalt mixture design incorporating certain waste materials. This research investigates the feasibility of substitution of virgin aggregates in asphalt mixes with recycled construction aggregates (RCA) obtained from the construction and demolition sector. A preliminary experimental study including determination of flakiness index, particle shape, wet/dry strength variation, water absorption rate, particle density, crushing value, deleterious material and weak particles was conducted on blends of RCA and virgin aggregates to evaluate the engineering properties of aggregate blends. Different asphalt mixes incorporating RCA at different rates were prepared and evaluated using a gyratory compaction. The results of the regression analysis showed that the asphalt mixtures containing 20% to 22% RCA provide comparable volumetric properties as the control sample, while mixes with higher RCA substitutions achieved higher air voids, and lower voids in the mineral aggregate (VMA), voids filled with asphalt (VFA) and binder film index (BFI). The results of this study suggested a feasible use of RCA for partial aggregate replacement in hot mix asphalt (HMA).

摘要

高比例的建筑和拆除废料导致大量的废料堆积。路面行业现在正在考虑采用一种可持续的方法来设计包含某些废料的沥青混合料。本研究调查了用从建筑和拆除部门获得的再生建筑骨料 (RCA) 替代沥青混合料中的原始骨料的可行性。对RCA和原始骨料的混合物进行了初步实验研究，包括测定片状指数、颗粒形状、湿/干强度变化、吸水率、颗粒密度、破碎值、有害物质和弱颗粒，以评估骨料的工程性能混合。使用旋转压实法制备并评估了以不同速率掺入 RCA 的不同沥青混合料。回归分析的结果表明，含有 20% 到 22% RCA 的沥青混合料提供了与对照样品相当的体积特性，而具有更高 RCA 替代物的混合物实现了更高的空隙率，而矿物骨料 (VMA) 中的空隙率、空隙率更低填充沥青 (VFA) 和粘结剂薄膜指数 (BFI)。这项研究的结果表明，RCA 可用于热拌沥青 (HMA) 中的部分骨料置换。矿物骨料 (VMA)、填充沥青 (VFA) 和粘结剂薄膜指数 (BFI) 的空隙率较低。这项研究的结果表明，RCA 可用于热拌沥青 (HMA) 中的部分骨料置换。矿物骨料 (VMA)、填充沥青 (VFA) 和粘结剂薄膜指数 (BFI) 的空隙率较低。这项研究的结果表明，RCA 可用于热拌沥青 (HMA) 中的部分骨料置换。