Dynamic Properties of Reclaimed Asphalt Pavement–Green Cement Blends for Road Base Layer

• Published in: Geotechnical and geological engineering Vol. 41; no. 6; pp. 3495 - 3511
• Main Authors: Consoli, Nilo Cesar, Tebechrani Neto, Aziz, Khajeh, Aghileh, Salimi, Mahdi, Specht, Luciano Pivoto, Vestena, Pablo Menezes, da Rocha, Cecília Gravina
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.08.2023; Springer Nature B.V
• Subjects: Acetylene; Asphalt; Asphalt pavements; Bituminous cements; Byproducts; Calcium; Calcium ions; Civil Engineering; Earth and Environmental Science; Earth Sciences; Gas manufacture; Geotechnical Engineering & Applied Earth Sciences; Gravel; Highways; Hydrogeology; Industrial wastes; Mechanical properties; Mixtures; Original Paper; Porosity; Roads; Roads & highways; Shear modulus; Silica; Silicon dioxide; Stiffness; Tensile strength; Terrestrial Pollution; Waste Management/Waste Technology; Dynamic modulus; Porosity/binder index; Reclaimed asphalt pavement; Green cement; Ground glass; Road base layer
• ISSN: 0960-3182; 1573-1529
• DOI: 10.1007/s10706-023-02470-0

Replacing resource-intensive materials with less impactful alternatives, particularly industrial wastes, or by-products, has been a trend in several areas, including the design and construction of infrastructure projects such as roads and highways. This paper examines the use of Reclaimed Asphalt Pavement (RAP—aged pavement containing asphalt and aggregates removed from existing roads) combined with Carbide Lime (CL—a by-product of acetylene gas manufacture) and Ground Glass (GG—a waste containing amorphous silica) as a blend for the road base layer. The pozzolanic reactions between calcium ions in CL and the amorphous silica in GG create cementitious compounds that were found to enhance splitting tensile strength ( q t ), maximum shear modulus ( G max ), resilient modulus, and dynamic modulus ( E* ) of RAP–GG–CL blends. The porosity/binder index provided an appropriate parameter for modelling all these mechanical properties. A unique equation between the dynamic modulus and the porosity/binder index was obtained for the frequencies and temperatures studied. Generally, mixtures with lower porosity/binder index provided higher strength and stiffness due to their lower void volumes and higher solid particles in their micro-architectural structure. Finally, an environmental analysis was carried out, showing that the benefits of this fully recycled alternative to gravel (traditionally used for base layers) can be further enhanced by creating dosages best suited to different scenarios.