ORIGINAL PAPER Laboratory Characterization of Cemented Tailings Paste Containing Crushed Waste Rocks for Improved Compressive Strength Development Ibrahima Hane . Tikou Belem . Mostafa Benzaazoua . Abdelkabir Maqsoud Received: 24 June 2016 / Accepted: 21 November 2016 Ó Springer International Publishing Switzerland 2016 Abstract This paper aims at investigating some physical and mechanical characteristics of cemented tailings paste incorporating different amounts of crushed waste rocks (hereinafter called paste aggre- gate fill, PAF) for underground stope filling. Different mixture formulations were prepared with three classes of crushed waste rocks (or aggregate) grain size, namely 0/10, 0/15 and 0/20 mm. The amount of crushed waste rocks in the PAF mixtures ranges from 10 to 50% by volume (% v/v) (or 8–45% by mass, %m) of dry mill tailings and crushed waste rocks. The results show that the addition of crushed waste rocks in cemented tailings paste mixtures allows a significant unconfined compressive strength (UCS) development after 28 and 90 days of curing. The highest UCS was obtained from the mixtures containing 50% v/v of crushed waste rocks of class of size 0/15 mm. The PAF mixtures with the coarser crushed waste rocks (class of size of 0/20 mm) exhibit some particles segregation. Keywords Mine tailings Á Crushed development waste rock Á Aggregate Á Cemented tailings paste aggregate fill (PAF) Á Water drainage Á Compressive strength Á Particles segregation 1 Introduction Mining industry generates a significant amount of solid wastes such as development waste rocks and concentrator tailings (Amaratunga 1991; Aubertin et al. 2002). Storage of these wastes on mine site surface is often source of environmental impacts. These wastes often contain sulphides and more or less heavy metals such as copper (Cu) and zinc (Zn) or metalloids such as arsenic (As). When sulphide minerals are exposed to air and moisture they can oxidize and produce, if there is no neutralizing potential, acid mine drainage (AMD) which favor the leaching of heavy metals, metalloids and all other contaminants present (Aubertin et al. 2002). One way of preventing and/or reducing AMD is the use of a portion of sulfurous tailings and waste rocks for producing mine backfill intended for underground open stopes filling. Mine backfill is a mixture of tailings or waste rocks, mixing water and with or without binding agent. Each ingredient may play an important role during the backfill transport through pipeline, its underground pouring and long-term mechanical behavior (Benzaazoua et al. 1999, 2002, 2004). Underground mine backfilling con- tributes to ground control and stability of excavations (Mitchell et al. 1982; Lun 1986; Dorricott and Grice 2002; Belem et al. 2002; De Souza et al. 2003; Belem and Benzaazoua 2008; Belem 2009; Yilmaz et al. 2014). Mine backfill is also beneficial for reducing the I. Hane Á T. Belem (&) Á M. Benzaazoua Á A. Maqsoud Research Institute of Mining and Environment (RIME), Universite ´ du Que ´bec en Abitibi-Te ´miscamingue, Rouyn-Noranda, QC, Canada e-mail: Tikou.Belem@uqat.ca 123 Geotech Geol Eng DOI 10.1007/s10706-016-0131-6