Short answers, pulled from the story.
Concrete floors appeared in the royal palace of Tiryns Greece dating to 1400 BC. This early use predates other known applications such as lime mortars used in Crete and Cyprus by 800 BC.
Joseph Aspdin patented Portland cement in England in 1824. He chose the name for its similarity to stone quarried on the Isle of Portland and William Aspdin continued developments into the 1840s earning recognition for modern Portland cement.
Eugène Freyssinet patented prestressed concrete techniques on the 2nd of October 1928. These methods compressed structures by tendon cables to strengthen them against tension and remain a key innovation in construction history.
Every tonne of cement releases one tonne of CO2 into the atmosphere. Cement production accounts for approximately eight percent of worldwide annual emissions with combustion processes accounting for forty percent of greenhouse gases while calcination contributes sixty percent.
OSHA placed stricter regulations on companies contacting silica dust regularly with an updated rule effective the 23rd of September 2017 restricted breathable crystalline silica to 50 micrograms per cubic meter. That deadline extended to the 23rd of June 2021 for engineering controls in hydraulic fracturing industries.