A concrete slab is poured over a base (of polystyrene blocks), and at set spaces, flows down between them onto the ground, to form deeper 'ribs'. Steel reo is supported by small plastic fittings or 'bar chairs'and form work sits around the whole outside. A peristaltic pump (aping human physiology) is probably used to pump the cement.
Local men with an Italian background often had a concreting business, afterall, concrete was an important innovative building material used in ancient Rome. Examples are found among its famous buildings and believe these were decorated with paintwork.
Gradually the old built environment gives way to the McMansion, the duplex and the town house which does help prevent suburban sprawl from getting totally out of hand.