Sustainable shotcrete production with waste glass aggregates

Abstract

This study employs statistical and experimental procedures to assess the applicability of crushed waste glass to replace natural sand in shotcrete production for use in tunneling, mining and excavation industries as a support system. Mechanical strength under different uniaxial and biaxial load combinations, fracture properties, and ultra-high-speed photography of the crack growth mode in the newly developed shotcrete mixes were studied and compared against the control mix at 0% waste glass inclusion. Results suggest that shotcrete mixes containing synthetic glass aggregates exhibit similar or higher strength properties (compared with conventional shotcrete with natural aggregates) at early and late ages in both fresh and hardened shotcrete samples. Under biaxial stress conditions, in particular, the new glass shotcrete designs demonstrate a higher load-bearing capacity of up to 35% increase. Compared to conventional shotcrete, replacing sand with recycled glass aggregates further exhibited the need for less water and binder consumption owing to the glass water-reducing effect. This in return could leave more water available for improved workability in the mixture hence producing a more cost-effective and eco-friendly shotcrete product. From the results, no impairment of performance was recorded by substituting sand with crushed waste glass even at a high substitution percentage of up to 100%; suggesting high improvement potential of crushed waste glass re-use in the shotcrete industry.

Utilizing Crushed Limestone as a Sustainable Alternative in Shotcrete Applications

“…Shotcrete has been employed in tunneling to prevent rock fallout caused by spalling failures since the 1960s in various global projects, such as the Lieraasen railway tunnel west of Oslo and the Jinping II hydropower station tunnels [41,42]. In Australia, where weak rock mass quality often poses challenges, shotcrete has gained significant attention in the tunnel and mining sectors, with substantial investments exceeding AUD 42 billion [43]. Despite the successful application of shotcrete in tunneling in areas where poor rock mass quality is encountered-specifically, in deep mines that are prone to violent rock failure in the form of rockburst and/or spalling-rock fragments breaking through the shotcrete layer were observed in some locations, such as the bending deformation and ejection of rock fragments and shotcrete in the Jinping II hydropower station and the distortion and spalling of shotcrete in the Liujiazhuang tunnel constructed in coal rich weak rock stratum during 2012 [35,42,44,45].…”

“…Despite the successful applications and simulations of shotcrete in supporting tunnels that are prone to spalling or bursting, limited research exists on shotcrete behavior at the crack initiation threshold-an essential predictive measure for in situ spalling failure. Shotcrete has been employed in tunneling to prevent rock f failures since the 1960s in various global projects, such as the L west of Oslo and the Jinping II hydropower station tunnels [41 weak rock mass quality often poses challenges, shotcrete has ga in the tunnel and mining sectors, with substantial investments e [43]. Despite the successful application of shotcrete in tunneling mass quality is encountered-specifically, in deep mines that a failure in the form of rockburst and/or spalling-rock fragmen shotcrete layer were observed in some locations, such as the b ejection of rock fragments and shotcrete in the Jinping II hyd distortion and spalling of shotcrete in the Liujiazhuang tunnel weak rock stratum during 2012 [35,42,44,45].…”

“…As the demand for tunneling operations continues to rise, shotcrete has become increasingly vital for ground support during tunneling and mining activities. For instance, over 800,000 m 3 of shotcrete were employed in Australia in 2018 alone, used in diverse civil projects, including basements, swimming pools, and embankments [43]. A key concern in the construction of sustainable infrastructure is the continuous diminution of readily available construction aggregates including sand [49].…”

An Experimental Evaluation of Hemp as an Internal Curing Agent in Concrete Materials

“…As such, the use of 'green' building materials can significantly reduce adverse impacts on our environment. Significant research has been reported highlighting numerous examples of using recycled products to replace typical materials in the construction industry [3]. The use of plant-based materials has also been reported to be an effective substitute for chemicals in concrete construction.…”