Until recently, terminating cross-passage membranes to TBM segments had been one of the unsolved mysteries of tunnelling. Thanks to recent innovations in gaskets and pressure terminations, all hydrostatic forces can be resisted to ensure they meet the ‘no damp patches’ specification. The most challenging part of any cross-passage termination is ensuring the membrane connects and […]
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Developing Membrane Termination Solutions to Deal with 3 Way Curvature in Cross Passages
Over the past 20 years, Bluey has completed waterproofing on hundreds of cross-passages, all of which have met the ‘no damp patches’ specification for rail infrastructure. All cross-passage entrances have curvature in three planes, making membrane installation, steel fixing and concreting far more complex than other tunnelling applications. The geometry adds particular challenges for the […]
How to Apply a Structural Shotcrete Liner and A Protective Coating in A Single Step
In the past, relining a highly acid environment has required two essential steps: 1) A layer of structural shotcrete is applied to improve the asset’s overall strength. 2) A sacrificial CAC protective coating is applied to ensure the structure’s durability by resisting sulphuric acid and other highly corrosive chemicals. The interchanging of teams, machinery and […]
Shrinkage Part 3: How to Achieve Shrinkage Compensation
Successful shrinkage compensation coincides with each phase of shrinkage. In other words, the magnitude of expansion and the timing of occurrence should be equivalent to the predicted shrinkage for each stage of the grout or concrete’s life. To achieve shrinkage compensation, we use a variety of techniques and products. 1. Reducing […]
Shrinkage: Part 2 – Selecting the Right Test Method to Measure Shrinkage
We are sure that you have heard the term ‘non-shrink grout’ and it is often backed up by the term Class C or a reference to ASTM C621. What Do These Terms Mean? Well for a start, there is no such thing as ‘non-shrink grout’ and further to that, ASTM C621 doesn’t even exist! It […]
Shrinkage: Part 1 – The Causes of Concrete Shrinkage
Failure to account for the causes of concrete shrinkage can lead to tension, cracks or even result in failure of the whole structure. In the next three-part blog series, we’ll take a detailed look at shrinkage and how we compensate against it to deliver consistent, controlled products in all temperatures and conditions. What is […]