While much of Australia was forced into shutdown at the height of the coronavirus pandemic, the infrastructure construction industry carried on as the Government acknowledged the sector as an essential service.
Infrastructure projects are booming across Australia with progress continuing at levels unseen in decades, supported by a new $1.5 billion stimulus announced by the Federal Government. The works include major tunnelling, road and rail projects across the country, including civil infrastructure and asset rejuvenation work. However, as the economy dips into recession, keeping construction projects on track and within budget will be critically important.
Mainmark is helping engineers and contractors to maintain productivity by using site specific asset remediation and water stop solutions that are cost effective, fast acting and non-invasive. Its range of specialised resins, gels and coatings are designed to revitalise, seal, protect and structurally reinforce a wide range of assets, including many that have been impacted by water ingress. Water ingress can occur due to geotechnical conditions that are either encountered during construction or have appeared over time due to factors including corrosion and weakened ground.
This blog (the first of a three-part series) takes a closer look at common issues that can occur during the construction phase of large infrastructure projects, and how innovative solutions now available in Australia from Mainmark can help engineers and construction professionals approach complex geotechnical issues when excavating and tunnelling. These solutions ensure infrastructure is not only safer and more structurally sound, they are also delivered more efficiently and cost effectively due to their unique properties and application methods.
Using specialised resins, gels and coatings to restore structural integrity to underground assets
Underground road and tunnelling projects may unearth ground issues that contractors have historically addressed using concrete. Water control treatments may be needed in areas with a low lying watertable, as encountered in many inner suburbs of Sydney. Deep excavation in these areas is susceptible to groundwater inflow which can significantly impact the cost and duration of a construction project. Equally, weaker soil conditions can contribute to subsidence problems and considerable remediation costs in the future.
Hard wearing solutions including specialised resins, gels and coatings can help to stop water leaks, seal joints and cracks, solidify soil and protect against corrosion. Mainmark’s specialised water control, chemical injection and cementitious grouting products are suitable for application in both wet and dry conditions making them particularly beneficial for large infrastructure projects with complex ground issues. Our advanced range of engineered solutions are non-invasive technologies that have been used to rectify and preserve all types of structures, including commercial buildings, industrial sites, residential and heritage properties as well as major civil infrastructure and mining projects.
Tunnelling and drilling projects where deep excavation is required can present unique geological and environmental challenges due to differing soil structures that can range from large fissures, clay seams, soft shale and wet sandstone. These varying soil substrates can cause issues requiring innovative solutions to limit or eradicate water seepage, address ground stability and improve the structural integrity of the tunnel or cavity.
Existing geological conditions, either identified prior to commencement or discovered during the course of the project, can also impact the construction phase of infrastructure works. For instance paleochannels (deep soil sediments), which are prevalent in some parts of inner Sydney, are ancient rivers filled with alluvium, a soft sediment which water easily passes through, located up to 50 metres below the ground; these can be a catalyst for water ingress into a tunnel cavity or ventilation shaft.
Addressing these types of complex environments requires specialised expertise in tailoring solutions for specific ground conditions in and around tunnels such as the major transport and urban renewal infrastructure that is currently under construction in Sydney and Melbourne. Mainmark can apply innovative water stop solutions, including rock and substrate injection treatments, using a range of specially formulated products such as cementitious grout, structural resin, silica, or acrylic polymers.
Each solution has high compressive strength properties for underground use, and some feature fast setting times to control water flows that can be as fast as 250 litres per minute. These proven high-performance water control treatments can be critical in emergency situations where fast flowing water needs to be addressed quickly, delivering both safety and longer-term asset preservation. For example, a specially formulated acrylic based hydro-structural resin with a fast and adjustable setting time was recently applied to a large tunnel to arrest water flow.
The right help at the right time
Major infrastructure projects, including tunnelling, commonly face obstacles throughout their long project timeframe. However, while there are always solutions to aid projects as unforeseen problems arise, most ground issues can be prepared for in advance using geotechnical data acquired during the planning phase. Having ground engineering experts on board before projects commence can help to design a better, site-specific approach to benefit the speed and overall budget of the project, and the structural integrity of the completed works.
Our next blog takes a closer look at broader waterproofing issues and how they can be invaluable for projects, such as basements and water tanks, that require structural linings and membrane coatings.
For more information and advice about our range of specialised resin coatings and asset remediation solutions, contact Mainmark on 1800 623 312 in Australia or visit our website.
By Matt McLean
Matt McLean is the operations manager for specialised resins and coatings at Mainmark. He is a concrete remediation, coatings, resins and waterstop injection specialist with long history of working with ground stabilisation and grouting technologies.