Did You Know?...... Interesting Cement FactJoseph Aspdin (d. 20 March 1855) was an English mason, bricklayer and inventor who patented Portland cement on 21 October 1824. The eldest son of a Leeds bricklayer, he began using artificial cements made by burning ground limestone and clay together. He named it 'Portland' as he thought its colour resembled Portland Stone. This first true artificial cement was the first real improvement on cement since John Smeaton had made the first modern concrete by mixing powdered brick and adding pebbles as aggregate back in 1756.