Cement and Concrete

cement-and-concrete

Cement and concrete are not the same thing although they are commonly incorrectly used interchangeably. Cement is an ingredient of concrete which is a very fine powder made from limestone, sand, clay, iron ore, water, and stone. Proportions of these ingredients are crushed and heated in a kiln to form what is referred to as “clinker”. The clinker is crushed again with gypsum and a number of other ingredients, and the result is a fine powder which is then referred to as “cement”. Aggregates in concrete such as sand and stone, coarse and fine, are for volume only and are not active ingredients in the hydration process

Chartres Cathedral

chartres-cathedral

Chartres, France (pronounced “shar-trey”) is a village which built the worlds tallest cathedral of its period. Standing a staggering 180′ tall, and taking 66 years to build, the Chartres cathedral was the first cathedral to use flying buttresses and be constructed in a cross shape as opposed to the classical rectangular shape the cathedrals of this period typically exemplified. Chartres cathedral is so grand in stature that Napoléon Bonaparte once said “atheists would feel uneasy inside these walls”