Here in Jakarta, 30-40 000 tonnes of sand and aggregate are trucked into the city every day. Good quality sand with sufficient angularity is becoming more scarce, and has to be hauled longer distances. The price of good sand has tripled in the last 5 years.
I do not know the consumption figures for Singapore, but they are now transporting some of their sand all the way from Thailand!
I found that on Wikipedia. It refers only to the production of Portland cement. Regionally, there are river dredges that bring up aggregate materials, and they are replenished by river flow. Transporting all of that is a fairly monumental task, that goes largely unnoticed. Local consumption of concrete is not huge, but there are nearby facilities for mixing aggregate and cement, and trucking it to sites, as there necessarily must be.
I recall a big to-do about some of the rebuilding in Afghanistan, when the requirement for America-sourced materials ran into the realities of shipping cement and aggregate half way around the planet.
Interesting info about the sand! The same problem applies to fracking sand used for oil and gas extraction. There are few sites in the United States that can produce the sand with the required properties and it has to be hauled long distances as well.