I've been hearing so much about concrete crumbling and that concrete structures have a life of 40 odd years before extensive work is required. Also concrete basements that leak and flood. The first thing that has sprung to mind is that many Roman constructions are also made using concrete. The Pantheon is the oldest domed building in the world. Built in Rome and extensively renovated around 145 AD, the dome is both 43.3 metres (142 ft) high and 43.3 metres across. This building is big and almost 2,000 years old and it's built of concrete! We even know the formula for Roman concrete. It is known their concrete was made from a pasty hydrate of lime, with pozzolanic ash and lightweight pumice from a nearby volcano, and fist-sized pieces of rock. Also the Romans developed waterproof concrete which can be poured under water and will actually set. So what is our problem?
For most of the time I have been able to read I have had an interest in archaeology. I recently came across an interesting theory taken from the observation that at least parts of the Khufu Pyramid (Great Pyramid) were "microstructurally" different from other limestone blocks. This is suggested that some of the immense blocks of the Great Pyramids of Egypt might have been cast from synthetic material - the world's first concrete - made 2,000 years before the Romans invented concrete! (see the article here) Linn Hobbs, professor of materials science at the Massachusetts Institute of Technology asked: -
Maybe the ancient Egyptians didn't just leave us mysterious monuments and mummies. Maybe they invented concrete 2,000 years before the Romans started using it in their structures.OK so why are 2,000 year old and even 4,000 year old huge concrete structures still standing requiring limited maintenance and here in my city all sorts of concrete structures (including my church and city bridges etc) need major reconstruction and repair work?
Learning lessons from the past is the historian's self justification for their discipline. We sometimes read the history of Israel with interest but don't realize that we are to learn the lessons of the past and that it has personal implications. We can be just as self-focused, rebellious and stiff-necked as the Israelites. We can be just as forgetful and ungrateful. If we are to build solid great structures then perhaps we need to learn from the past both the good and bad points.
