AS Australia’s mining industry continues to cope with the challenges of low commodity prices and the construction industry looks for greater efficiency, a number of familiar themes are arising. Aside from a central focus on lower operating costs, companies are looking for improved sustainability, technology and automation within their businesses to boost profitability and improve competitiveness.
|The TYTRO® Shotcrete System from GCP Applied Technologies offers benefits in terms of cost and efficiency.|
As such, there’s increased interest in the use of shotcrete for tunnelling or other permanent openings as well as for rock stabilisation. Shotcrete is not new but there have been significant advances in the admixtures in recent years, which have provided improvements in the speed, efficiency and cost of using shotcrete.
One new product is the TYTRO® Shotcrete System from GCP Applied Technologies, which is attracting attention in construction and mining. Since TYTRO was introduced to Australia and New Zealand in 2014 it has grown its user base and is now offered through over 40 premix plants across the region. It has featured in some large recent infrastructure projects and has been used by large mine operators.
There is increasing interest in the use of shotcrete for mining applications, which reflects a change in mindset as miners put greater focus on the cost-per-tonne or cost per hour of operations.
In hard rock mining there are several applications for shotcrete and most offer numerous advantages over alternatives such as mesh and rockbolts. Applications include drill and blast work, rehab to support mine repairs and damming the stope.
In soft rock mining there is still a preference for mesh and rock bolts but shotcrete offers a number of benefits. In particular, there’s increasing interest in using it around installed pillars to get extra strength into these structures which are typically exposed to very high forces.
In construction, and specifically tunnelling, shotcrete use is also increasing. Tunnelling applications include supporting the drilled substructure, or acting as lining reinforcement. Shotcrete is versatile and can play a varied role on site, while offering better efficiency.
Companies using shotcrete in mining and construction are increasingly choosing the TYTRO Shotcrete System, largely because of productivity and cost advantages. TYTRO is a complete state-of-the-art admixture solution that is faster to apply and less expensive than other systems while offering higher quality.
One of the most advanced products of its kind, the TYTRO system includes a number of industry-leading innovations including a nanotechnology-based rheology control and modifying agent, and patented macro synthetic fibres. In addition, the system has other new admixtures that enhance productivity during spraying and deliver stronger performance on application.
Typical project costs are around 10% lower than alternatives. Savings are delivered in several ways, all of which provide efficiency improvements.
A significant way is by optimising the shotcrete mix composition. Major contributors to this are the TYTRO RC 430 rheology control admixture and TYTRO RM 471 rheology modifying admixture, both unique to GCP Applied Technologies.
TYTRO RC 430 replaces silica fume which typically delivers the strength, durability and ease of pumping qualities that shotcrete needs. The big advantage of TYTRO RC 430 is that just 0.6-0.8% in the mix replicates the effectiveness of 5% of silica fume.
The use of silica fume in industrial applications continues to decline and TYTRO RC 430 offers an advanced way of substitution without performance loss. While other silica fume alternatives exist, TYTRO RC 430 is the only one that doesn’t add cost to the shotcrete mix.
There is particular enthusiasm for TYTRO RC 430 and TYTRO RM 471 in applications where workers are more closely involved in the shotcrete mix process, such as swimming pool construction. Here, silica fume will typically be added to the mix by workers on site. Aside from the heavy weight of the bags, typically 20kg to 30kg, there is always an element of risk with workers close by.
Longer term, using the TYTRO system means less wear and tear on spraying equipment largely thanks to the unique TYTRO RM 471 additive. Including this means shotcrete can be pumped at a lower pressure than alternatives, and lower pressure in any equipment inevitably puts less stress on components. Also, because it can be applied at higher levels of viscosity, it moves through the equipment’s pipes more easily. Despite being more viscous, the TYTRO system maintains its cohesion and will not lose shape.
Cost savings with the TYTRO Shotcrete System are also delivered through lower levels of rebound achieved when sprayed on surfaces. Rebound can be 5-8% lower, which means less material wastage and fewer passes with spray equipment to get the desired thickness.
More strength is assured because TYTRO offers a stronger ‘bond-to-rock’ quality, which also allows greater thickness to be achieved in one pass with spray equipment. Work can recommence faster thanks to the TYTRO SA 530 and TYTRO SA 535 accelerator admixtures, which provide more rapid early age strength.
In an age of business disruption, companies understand that it is no longer acceptable to continue with operations ‘because that’s the way we’ve always done it’. New and better ways of managing operations have to be found, and companies that fail to adapt to new technologies or ways of working will be left behind.
The practical advantages of the TYTRO system are clear, but GCP Applied Technologies recognises that having an industry-leading product is not enough - it must be supported. Accordingly, GCP has developed a team of product experts and support staff who work closely with users.