I'd like to see some data on the sand's properties. Not any type of sand can be used to mix concrete. The properties you want the concrete to have and the type of cement that is available are also vital factors. (Fun fact: Saudi Arabia has to import sand to make some types of concrete.)
Being able to build concrete structures on Mars would help longtime Mars missions, from landing pads to crew shelters etc.
Ideally Mars could have types of sand that cas cement-like properties, like puzzolani. The Romans used that for structures like the foundations of the Coliseum or the cupola of the Pantheon - 2,000 years ago.