There is evidence that the Maya developed prefabricated structures for construction efforts and transported them some distance to selected construction sites. This was a part of the commercial matrix of Maya culture. Buildings have been excavated that were abandoned in an unfinished condition. The various stone element of the facade had been laid out on the ground at the front of the building ready to be installed, when the construction was abandoned.
It is known that Maya possessed a lucrative market in the construction industry. It is logical that smaller urban centers, without specialized building trades, would rely on a larger construction center with specialized trades to produce the building components for a widespread market. Shipping would be carried out by manpower with components sized for tumpline use. Again, the Maya were ahead of their time: the first references in Europe for the case for prefabrication came from Leonardo da Vinci. Many facades of elegant Maya buildings were constructed of mosaics of carved stone that were prefabricated off-site and transported to the site to complete the facade.
High-Rise Buildings in the Rainforest
“Build it and they will come” may be an older catchphrase than we know. The attractions and comfort of the city life increased migration away from the hinterlands and into urban centers. As cities grew, there was a constant demand for new workers and expansion of the urban core. Maya engineers developed structural engineering mechanisms, which they combined with innovative, high-strength building materials, to meet the demand for monumental buildings that engendered the magnificent Maya cities.
The Maya structures were constructed of high-strength materials using a hybrid of linear and circular structural mechanisms that generated graceful buildings towering above the sprawling cityscape. These unique structures, unlike any other style in world architecture, represented a diverse variety of monumental buildings including pyramids, palaces, temples, observatories, administrative buildings, and ball courts. The buildings featured creature comforts and amenities including plumbing, potable water, ventilation systems, and sewerage disposal systems.
The sophistication of Maya structural engineering was a synergistic product of high-strength building materials and engineering mechanisms that resisted seismic events, hurricanes, and the harsh environment, while solving the complex geometries required by the function of the building and by the exotic style of monumental buildings.
Maya High-Tech Building Materials
Maya engineering technology exploited native resources to create high-strength, technologically advanced construction materials. These materials are quite similar to products used in modern construction technology. The range of high-strength materials of construction applied by Maya engineers greatly exceeded the capabilities of European materials of construction until the 19th century. The shopping list of materials developed by Maya engineers is extensive. The following materials of construction are native and were developed as high-strength materials used by Maya engineers:
Native Limestone
The Yucatán is an extensive limestone shelf extending deep below the surface. The native limestone is a multi-use building product and is the basis for cement, aggregate for cast-in-place concrete, and raw material for cut stone masonry and the material for carving Maya sculptures. The compressive strength of limestone exceeds 5000 psi (34.5 MPa), which is more than acceptable for structural purposes.
Hydraulic Cement
Maya technicians invented the process for fabricating hydraulic cement and applied this multi-purpose building material to construction projects before the year 300 BC. They used hydraulic cement as the principal binding substance for the majority of building materials in Maya construction, including cast-in-place concrete, mortar, stucco, and composite structures. The demand for the fabrication of hydraulic cement was continuous, and the production of cement material required a high demand for timber to be used as the fuel for the process. The collection of the timber fuel at times resulted in the clear cutting of forests and greatly impacted the environment of the hinterlands of the city-states.
Cast-in-Place Concrete
Today, the most popular building material is cast-in-place concrete. The same was true during the Maya Classic Period. This durable construction material is formed by a paste of hydraulic cement and water, which coats the surface of the stone aggregates added to the mix. The cement and water paste reacts through a chemical process called hydration. The paste hardens and bonds with the aggregate, gaining strength to form the rock-like mass known as concrete. One great advantage to constructing with concrete is that the process starts as a pliable, flowable material when newly mixed; when placed within the structural forms, it assumes the shape of the formwork. When the chemical hydration process is complete, the paste hardens and forms the hard, high-strength material known as concrete. Cast-in-place concrete was used by the Maya to construct structural members for buildings, paving, walls, and reservoirs.
Composite Limestone and Cast-in-Place Concrete
The invention of cement was a great step forward for Maya technology. However, the real breakthrough in increasing the strength of structural building materials was combining the beneficial capabilities and strength of cut limestone with cast-in-place concrete to create a high-strength composite material. This combination not only produced a strong, durable material, but also eliminated the prerequisite formwork required of Roman or modern concrete structures.
This composite system of materials used the cut limestone facing walls to develop the exterior and interior surface of the wall structure in lieu of wooden forms. When the fluid concrete is placed between the walls, the interior face of the limestone wall elements becomes coated with the concrete paste and creates a strong surface bond with the interior concrete. When the concrete has hardened, it technically becomes a part of the limestone walls and develops a composite structural system that has an exceptionally strong weight-bearing resistance and enhanced lateral resistance. The composite structure is stronger than its parts. This type of composite structure was used for arches vaults, walls, and roof structures in Maya buildings.
Limestone, Masonry, and Mortar
The application of cut limestone blocks bonded together with cement mortar was used to build load-bearing and non-load-bearing walls. Structural mortar is a homogeneous mix composed of cement, fine aggregate, and water. When water is added to the cement and aggregate and mixed, the hydration process is activated, and this malleable paste is applied to the surface of the limestone blocks. The mortar bonds the adjacent masonry blocks together to form a strong structural wall system. These walls were used as partitions in buildings to develop interior room-demising walls and exterior walls.
Stucco
Stucco is an applied plaster consisting of cement, aggregate, and water. Maya engineers and architects used the material in multiple ways for interior and exterior applications. It is generally considered that stucco was applied over the rough stone surface as a smooth aesthetic finish that could then receive paint or other finish materials. However, the waterproofing qualities of stucco are one of the major reasons that the Maya structures were able to resist the attack of their harsh environment. The application of several coats of stucco not only resisted water intrusion into the matrix of the structure, but deterred the growth of fungus, mold, and jungle vegetation that could penetrate the surface of exposed stone and pry apart the interior structure. Stucco also served as the base material for three-dimensional sculptures of Maya art and as artistic decoration on the facade of Maya structures.
Bright colors of paint were applied to the walls and facade sculptures. This presented a dramatic effect, but the impact of the painted building was accelerated by the addition of mica into the mix of the paint for the surface coating. The lustrous pigments were made with mica to give the building a dazzling effect in the bright tropical sun and generate a lustrous effect in moonlight. Studies have indicated that major buildings received numerous coats of stucco and luminous paint over the years. Each
new coating of mica paint gave the sacred buildings a dazzling appearance. Again the Maya were ahead of their time: mica is used in modern paints, for the similar purpose of creating a shimmering appearance on a painted surface.
The interior and exterior coatings of stucco, and the brightly colored paints that covered the major structures, were constantly repaired and replaced during the Classic Period. After abandonment, this moisture-resistant material reinforced the battle against the onslaught of the environment, until centuries had passed and the ceaseless attack of the jungle growth finally broke through the outer barrier of stucco. The composite stone and concrete structures resisted the external environment for additional centuries after the stucco had been breached and enabled the monumental structures to survive the jungle attack.
Multiple examples of extant interior and exterior stucco are located in Maya cities. Figure C-5 indicates the stucco remaining on the interior of vaulted ceilings.
High-Strength Structural Timber
The Maya world was fortunate to be the homeland of several varieties of dense, high-strength tropical hardwoods, which were also resistant to insects and decay. Several of these timber products possessed the tensile strength exceeding that of cast iron. The wood was used for lintels and beams due to its high strength, durability, and resistance to termites and decay. Some of the timber beams survive today, 1,300 years after being installed in Maya structures (Figure C-5). High-strength, durable structural timber includes sapodilla or chico zapote (manilkara zapota), cedar (cedrela odorata), and mahogany (swietenia macrophylla). The tensile strength of chico zapote is more than 20,000 psi.
High Tensile-Strength Rope
Hemp rope or henequen is indigenous to the Maya world. The strong fibers of this plant were collected from the sword-shaped leaves of the agave fourcroydes plant. Its strong fibers were woven into high-strength rope and used in multiple applications by the Maya. This rope had a tensile strength of 18,000 psi. In construction, rope was used as a suspension cable in bridges, a hoisting cable in construction, as a trussing connection device to secure joints of timber structures, and for other construction uses, including fabrication of containers for transporting building materials. In addition to construction applications, this strong and pliable material was used for baskets, clothing, and hammocks.
This very same rope became indispensable throughout the world during the 18th and 19th centuries, when it was needed for ships, thus becoming was an extremely lucrative export from the Yucatán. It was used by the construction, marine, and other industries that required rope cable before steel or nylon cable was available. This one export made the Yucatán and its capital city, Mérida, extremely wealthy.
Latex
The milky latex of the sapodilla tree produced a natural rubber and gummy substance, which was used for several products, including chicle, the basis of modern chewing gum, and the coating for waterproof fabrics. In construction, latex was used as an additive for concrete, as an adhesive to secure jade tools to wooden handles, for the waterproofing of structures, and for gluing structural members together. Latex is a natural polymer that, when used as an admixture for concrete, enhances the bonding, durability, and workability of the concrete.
Concrete Admixtures
The use of admixtures to improve the durability of cast-in-place concrete has been identified from various sources. The addition of volcanic ashes, powder of burned clay, and a by-product of the process of making tortillas has positive effects on concrete workability, durability, and strength.
The flowers from the morning glory vine last for a single morning and die in the afternoon. However, the discovery of the merits of the chemical agents collected from the juice of the morning glory vine has been known for thousands of years. Maya engineers added the juice of the morning glory vine to the concrete mix to induce waterproofing in the concrete. Maya used the juice from the species ipomoea alba to convert latex gum from the castilla elastica into bouncing rubber balls used in the Maya ball games. The sulfides in the juice of the morning glory vine served to vulcanize the rubber when the two substances were heated together. The Maya learned this process from the Olmec, who predated the process of vulcanization by Charles Goodyear by 3,000 years.
Realization of a Maya Structure
The conception and construction of a Maya structure initiated with the patronage or sponsor of the structure. Whether the goal was to construct the tallest pyramid to enhance the glory of the city, to construct of a luxurious palace for the comfort of an elite family, or to erect a structure for commercial purposes that kept the big wheel turning, someone had to fund the project. When the purpose, size, and level of luxury had been established, the planning for the project would begin.
Remnants of fragile documents, including the plans and designs of engineers and architects, did not survive the collapse of the Maya and the ravages of time. However, it is known that the Maya were expert at paper production. They were also skilled in mathematics, written communication, and astronomy, all of which are part of the process of converting conceptual ideas into hard line drawings on paper for visualization before physically transferring the drawings of a structure into the “bricks and mortar”—or stone and concrete—of a building. To develop their drawing or plan for a project design, architects and engineers used straight-edge tools similar to those used by modern designers prior to the advent of the computer.
The layout of the building on the site would follow the guidelines established by the design drawings. The outer perimeter of the structure would be demarcated with wooden posts and “string lines” made of hemp cords or rope, and 90-degree corners were accurately defined with a string line using a set of lines and a circle. It is known that the Maya possessed a defined measurement system with units of approximately 0.96 meter. Using this system, the outer perimeter of the building would be laid out. The verticality of walls and their angular intersections would be defined using “plumb bobs.” Water levels and building squares were used in “truing” the construction of the building.
Mobilization of the construction process would follow conventional standard methods used throughout the world. Because beasts of burden were not native to the Americas, Maya technology solved the issues of transportation of construction materials by using the efficiency of readily available manpower. Construction materials were transported in quantities and weight that could be transported and handled by one man. Stones cut for construction were sized to be transported by one man. The device now known as the tumpline was used for overland transport and construction lifting. This load-carrying device, which carried the Maya civilization during its glory days, is still used today for transporting loads. A look at Maya constructions makes it clear that the vast majority of the cut stones could be transported by one man and a tumpline. Loose or fluid construction materials, such as sand, cement, small stones, and wet concrete, could easily be transported using the manpowered tumpline and a container woven of sisal. This method of construction was used in Mexican construction until well into the 20th century.
As the construction of a structure grew taller, access to the upper construction levels was carried out by work scaffolds made from trussed timber poles. These cross-braced towers were stable, conformed to the geometry of the building facade, and were accessed by ladders. Maya artists did not normally depict common scenes such as construction sites. However, a mural on the wall in the temple of the warriors at Chichen Itza indicates the use of trussed timber towers, similar to scaffolding used in construction today. The mural shows the scaffolds used as a “war machine.” The mural indicates a warrior using an atlatl standing on top of what appears to be a 6-meter trussed tower. The tower is being steadied by warriors at the base as the elevated hurler launches his dart into the besieged city. The height of the tower would increase the range of the atlatl by 18–27 meters; the tower had a great advantage over the capabilities of the defenders at lower levels. A similar type of scaffolding would have been used by laborers build
ing Maya structures.
As the construction progressed upward, the ubiquitous hemp rope was used to hoist construction materials to the appropriate level for installation. The application of stucco on the facade was carried out using tools that are similar to today’s stucco application. The first coat could be applied by hand and flat boards, and then finished with trowels. Murals were sketched out using graphite crayons, the colors were mixed with mortars and pestles, and the murals were applied with brushes.
The Lost Secrets of Maya Technology Page 15
