The composition of OPC has remained largely the same since last century, and the mechanisms of OPC hydration and structure of C-S-H remain difficult to interpret. However, major advances in the use and performance of cement have come from three fundamental areas: (1) construction technology; (2) the science and engineering of composite materials; and (3) admixture chemistry, both organic and inorganic.
Sea route trade started with early expedition in Europe, moved to medieval Asia before taking huge leap in 14 th century AD. When Portuguese arrived in India in 1457 and found that they could buy pepper for a little money in Calicut and sell them at 25 times price in Europe they were seeing a new dawn – using sea transport to exploit an interregional arbitrage. It was not just a commercial success. By bringing spices to the European population in far greater volumes than could be transported overland by camel, live became better and, in modern economic jargon, ‘added value’. Over the succeeding six centuries, as shipping became more efficient, the opportunities to add value by moving goods around the world increased and sea trade grows giving shipping a central role in the globalization of the world economy. Today 11-billion-ton cargoes move between more than 3,000 +major commercial ports.
Unarguably no form of industry had played such a central part in economic voyages and globalisation over thousands of years. Railways and airlines, shipping’s closest counterpart, had history of barely 150 years.