Today, the use of sprayed concrete in mines, tunnels and other civil engineering structures is an important and integral part of successful, highly productive, and safe rock support systems.
Normet’s Tamshot AF range of high performance alkali-free accelerators for sprayed concrete applications, have been formulated for improved fast-setting and safer performance over standard sulphate based accelerators. The new generation set accelerators, both stable suspensions and clear solutions, make site-handling logistics and longer term stability more favourable. They also bring the added benefit of better reactivity with the decreasing cement quality available to the markets these days.
Normet’s TamCem range of superplasticiser technologies have been formulated to give exceptionally high water reduction based on customised blends of specific polycarboxylate copolymer technologies. These superplasticisers will usually provide an open time of 3 to 6 hours. Added open time often requires the use of Tamcem HCA – a hydration control admixture. Without hydration control technology, the use of modern day sprayed concrete would be very challenging. Normet’s new Tamcem HCA is a very effective concrete hydration control admixture added at the batching plant. By adjusting the amount added, the “open-time” of fresh concrete can be extended dramatically anywhere from 4 hours to 2 days! This flexibility gives you complete control, and the sprayed concrete can be awakened immediately upon the spraying of our TamShot AF range of set accelerators.
Normet is at the core of modern technology with our comprehensive range of microfine and ultrafine cements, permitting contractors to undertake their works efficiently and effectively with products developed specifically for the chosen application. Our range of fast setting MFC grades for example used predominantly for pre-excavation grouting (PEG), offer time savings in the tunnel excavation cycle, ultimately contributing to lower overall project cost.
Normet’s ultrafine cements (UFC) have been designed for ground engineering applications where superior penetration into soils or greater reduction in rock hydraulic conductivity is required. TamCrete microfine cements are finely ground Ordinary Portland based products for pre and post excavation grouting. The superfine particle size, together with the addition of TamCem Superplasticiser provides superior penetration into tight joints and fissures providing a water-tight grouted rock mass. TamCrete ultrafine cements are typically used for stabilisation or consolidation of soils where standard ce¬ment types are not suitable due to their larger grain size. Normet Ultrafine cements have extended the range of soils that can be treated through permeation grouting with 80% of fine soils groutable with the UFC range of products.
Injection resins have been used extensively in mining, civil engineering and the general building industry for many years and continue to play an important role in controlling or preventing water ingress, binding and improving soils through to rock consolidation and rock strata grouting. Our resins have been designed specifically for these applications and comply with country and site standards and more importantly, environmentally safe and user friendly!
Normet’s water control resins are used throughout the full cycle of construction. From underground excavations such as shafts, tunnelling and basements through to above ground injection on bridges, roof structures to viaducts. In fact, our resins are used wherever water is a problem and needs to be controlled or permanently resolved.
Normet’s range of polyurethane silicate resins are new generation systems used predominantly in the mining and tunnelling sector. Our Tampur 116T is a two component 1:1 ratio resin that reacts to form a non-expansive, solid compound that gains considerable adhesive, compressive and tensile strength within minutes. Ideal for injection into high convergence zones in deep mining or tunnel excavations to improve rock strength capability and as a binder for loose rock formation. Tampur 116T is also used extensively to secure rock and cable bolts allowing for early tensioning.
RBG (Rock Bolting Grout) is ideally suited for securing all type of rock bolts where early tensioning/loading is required along with full rock bolt encapsulation.
Tampur RBG is available in varying grades to suit both an automated or manual injection process and to allow for local ambient and rock formation temperatures. Tampur RBG incorporates a gelling agent that produces a non-sag resin once the two components are mixed and injected.
Tampur 117 is designed for cavity filling in hard rock mining, goff filling in coal workings to general void filling for tunnelling and civil engineering projects. Tampur 117 reacts within seconds to form a high expansive, lightweight foam, which is economical, non-toxic, fire resistant and user friendly.
Rock bolts are an essential part of these systems and have to be efficient, reliable, easily installed with standard equipment and reduce the need for downstream rehabilitation. Our team at Normet’s Rock Reinforcement business line are continuously developing new innovative products that can help to solve some of the toughest challenges.
Our D-Bolt is widely used as part of the ground support system in some of the largest and deepest mines and tunnels around the World. Our recently developed and patented Locally Anchored Self Drilling Hollow Rock Bolts in combination with our construction and mining chemicals, offer innovative solutions to areas where conventional systems are not delivering results. In addition, we are devoting time and resources to further develop the next generation of rock reinforcement systems, creating even safer underground environments.
The D-Bolt represents the new generation of energy-absorbing rock bolting systems, specifically designed for efficient and reliable rock reinforcement, in both squeezing and burst-prone strata conditions. Normet’s patented D-Bolt technology is based on a smooth steel bar with a number of anchors along its length. The D-Bolt is constantly being use as a vital rock reinforcement safety device at leading mines throughout the global mining community.
The newest addition to the D-Bolt family is our Connectable D-Bolt, a system that is extendable through specially designed couplings. This bolt type is especially effective for smaller profile spaces where there is a need for longer bolt anchoring offering an alternative to cable bolts. Normet’s connectable D-Bolt® has the same features as our standard D-Bolt® model with the couplings offering both an operational and functioning role.
For areas where ground conditions are very difficult and demanding, Normet designed an innovative, patented bolt combining the features of the Self Drilling Anchor (SDA) and D-Bolt. Normet produces two types of anchor taking into consideration design and load bearing capacity. For the North American mining market, Normet designed the bolt to reflect Nevada mine conditions. We call this the SDDB – Nevada type. The anchor is a 2400mm long Self Drilling Hollow Bar made from a single piece seamless tube with a diameter of 32mm. The thread is ISO R32 rolled with uneven length from each side. The material for the SDDB Nevada type has been carefully selected to respond to our customer’s inquiry for yield load and elongation at break. The bolt is typically used for single length applications although it can be extended with couplings to reach the desired length where necessary. This anchor utilizes a drill bit and longer root threaded section for anchorage.
Source: Normet Group Oy
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