But the cement used by most contractors and available at building merchants is the general use cement with a lower compressive strength. If the concrete design strength is so required, one would have to use the structural grade and I am sure any ready mix concrete plant would do so as would contractors on large projects. But for the typical home dwellings the general use cement will be used for the concrete work and mindful of the concrete forming and placing techniques common in DR that works.
https://www.cemexdominicana.com/product … ntos/titanDR cement is good and the Caribbean region is home to some good and fine blend cements.
But the techniques used in concrete construction can be very iffy to add to low skills levels on places.
Most concrete construction is a world away from what you would have seen in the USA and Europe. Outside of the main cities, there are few concrete batch plants and most domestic concrete placement is by manual labour mixing in 1/4 or 1/3 cyd cement mixers and cement mixers with hoisting devices. A pump would be a luxury for much of the country and the concrete batching would need to be as good to avoid plugging and for sure concrete truck drivers will add water to their units if there are delays or long hauls. The manual work is honed by the domestic dwelling construction gangs with so many shovels of aggregate and 2 or 3 bags per batch with water added as required - and because it is manual work they tend to add far too much water. The aggregate will come from graded river gravels in most but not all instances and will be variable. Also, few maestros outside major companies and cities have concrete compaction pokers and if they do it will be a 1 or 1 1/2 inch electric poker. The preferred option is to over cement the concrete mix and add water and use hammers and prodding sticks to compact. Yes very poor practice but it is so common and you will see many instances of honeycoming on many doestic dwellings if you are here to check the work. If not it will be plastered over. So back to design and make sure you have a seismic design over reinforced based upon low concrete strengths which is what will result with imperfect compaction and high water cement ratios. The steel reinforcing bar strength is another area to consider. Most reinforcing bar is manually bent here and can be over bent. If the rebar is produced here the strength may not be up to the standards one has been used to. Most steelfixers don't understand seismic detailing especially in relation to link spacings at key junctions and reinforcement of hollow blockwork.
As for formwork and scaffold, if any, well that is another world. It is rare to see metal props to support slabs even on multi storey apartment blocks in the Santo Domingo. Some of the bigger contractors have invested in proprietry formwork support systems and scaffold but most use wood poles. So you will need to adapt formwork support calculations and adapt how you check the formwork. And the ply deck, column and edge formwork could have had a hundred uses in many instances and never seen a form release agent and have damaged edges and holes. Concrete curing is something most maestros don't understand and with both wet concrete and no curing under a hot sun shrinkage cracking is a common sight. some flood the concrete slabs after placement but often they are too tired and leave it until the following day. So don't strike soffit formwork too early and give it as long as possible to gain strength even up to 28 days! But many don't and strike after a week! They tend to add a screed over flat roof construction normally to seal those shrinkage cracks and create falls. The roof drainage philosiphy preferred here is to drain the roof from within a blockwork parapet so ponding is possible if the drains get blocked.
Water for concrete - if you understand DR you will understand there are shortages of good quality water throughout the land so the source of your water for concrete is worth investigating especially if in coastal regions in case there are salinity issues.
It is a learning curve here from working in oher Caribbean islands and a huge learning curve form Europe and USA.
One real positive is that there are very good young Dominican engineers and architects coming through the system and gaining excellent experience on the big development projects that have taken place over recent years and so standards should be on the up going forward. Equally construction skills are being developed as a result but often it is Haitians that are benefitting.
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