The current accepted timeline is that Khufu’s pyramid (the largest of the Giza Pyramids) was constructed in 23 years (2589 – 2566 BC). There is endless debate on the work force and construction methods used to create these majestic wonders. Each debate involves a series of assumptions. What we have learned (recently) is that the pyramids were not built with slave labor. The effort was a massive public works project. Egyptian citizens worked on temple structures during of ‘off-season’ of an agricultural society. During planting and harvesting, the populace worked the fields and farms. The remainder of the year, the masses worked (for pay and subsistence) on these structures. The debates surrounding the workforce look at maximum numbers working maximum hours. Again, countless assumptions.
The field of archeology knows that the ancient Egyptians had forms of concrete and mortar from wall paintings dating well before the construction of Khufu’s pyramid (from wall art and plaster in Djoser’s burial chamber).
An alternative proposal has surfaced over the years and has merit (with a lower number of assumptions). By using a formed rock substitute (a concrete like material), the construction of these large pyramids fits the documented timeline and workforce. This method would still require some blocks to be quarried and placed, but most of the structure would be made from the materials locally available (water, sand, and a reactive material such as lime and natron). The resulting compound would resemble a sandstone or limestone substitute with the properties of being formable and easy to transport in smaller quantities. Such a compound would allow a number of workers to carry baskets of ‘wet concrete’ like materials and deposit them in-place. This would allow that number of workers to cast a block of many tons, one basket load at a time.
Again, using Ockham’s Razor as a test, this now starts to put clarity into the questions of how the pyramids were constructed. It also answers the dilemma concerning the quality of stonework with copper tools and the fineness of fitted joints between the massive stone blocks.