Generally we don’t model other end-of-life reuse of materials other than what is available according to industry data (what’s listed under ‘Disposal & Recovery’ options). Depending on the material’s service life, usually this is because it is very difficult to guarantee what will happen to that material at the end-of-life. Take for example your hollow concrete blocks. They should be able to last for 100 years – is there a way the developer/designer is able to guarantee the end-of-life disposal/reuse method for that concrete block in 100 years? Most product warranties don’t even last for more than 10 years. Even for life-time warranties, it is not a guarantee that they won’t get disposed of pre-maturely due other external factors (change in tastes, functionality, unexpected damage etc). Therefore we tend to go with industry avarage data of typical rates of reuse/recycling for the materials because they are based on actual facts not predictions.
In saying that, if we want to inspire change, we need to be able to give people an idea of whether a venture is worth pursuing. So, yes it is possible to model scenarios where a material is repurposed at the end-of-life. You can choose ‘No disposal method’ under ‘Disposal & Recovery Method’ however this should only be modeled in the ‘Scenario’ design, not as the ‘Proposed’, ‘Final’ or ‘BAU’ designs.
Naturally, there is very little industry information on the impacts for those options (how will the concrete blocks be reused?) therefore your assumptions must be declared transparently and in detail in your LCA scenario and you should try to account for all possible impacts related to that process (transporting concrete blocks to processing plant, perhaps processing equipment impacts of blocks if any etc?). You should also have a read of how EN15978 allocates the benefits of recycling for LCA purposes here: https://support.etoollcd.com/index.php/faq/etoollcd-questions/closed-loop-recycling-en15978-work/
Therefore, until that data becomes industry ‘typical’ (the LCI is constantly getting updated so it may well happen for concrete building products), we generally go with what is currently available in the latest dataset. Scenarios may be modelled however it mostly speculation rather than a solid recommendation/strategy.
This topic is also related if you are considering timber products: https://support.etoollcd.com/index.php/forums/topic/timber-end-of-life-impacts/
Hope that answers your question.