Historically, "cyclopean" referred to a building technique that superimposed large stone blocks together without any mortar. This allowed for a diverse array of structures across various civilizations, including defensive walls, talayots, navetas, nuraghes, temples, tombs, and forts. Nowadays, the term applies to any ancient structure consisting of large stones superimposed to form a polygonal shape.
Nowadays, cyclopean concrete, also known as cyclopean cement, is the hybridization of these ancient techniques with modern building resources. The key difference between cyclopean concrete and simple concrete is the size of the rocks added to the mixture. Simple concrete uses smaller rocks in the mixture while cyclopean includes larger rocks like boulders. In simple concrete, coarser additives have size limits based on the space in the framework or the necessary durability and can typically measure no more than an inch.
The economic properties of cyclopean concrete, due to the fact that the size of the stones decreases the amount of cement needed, made it a popular material for constructing foundations (it was gradually replaced with other materials due to its technical and weight-bearing limitations) underwater projects, retaining walls, and floors.
In contemporary architecture, cyclopean concrete is still used where and when permitted by structural requirements, for example, projects with low required resistance or structures with lighter load-bearing capabilities. For the Venecia Park in Zaragoza, Spain, for example, Héctor Fernández Elorza and Manuel Fernández Ramírez constructed a 100 meter long and 10 meter high cyclopean wall. The design was centered on a linear urban structure that wouldn't hold more than its own weigh. Rather, it would serve as an acoustic barrier to mitigate the noise pollution from the surrounding traffic and protect the surrounding residences. As previously mentioned, the size of the stones allowed the project to use less concrete, thereby cutting its overall costs. In fact, the rocks are usually the most expensive part of the mixture.
In Jesus Aparicio's Skyline House, the outer walls are made with cyclopean concrete with stones sourced from a nearby quarry. This design decision, one of many made to reduce the structure's environmental impact, also emphasizes the desire to connect architecture with the surrounding environment. In the words of the architect, "the rugged texture of the walls blends the house into the surrounding nature, inviting the lichens, mosses, and plants to make a place for themselves in its crevices."
Other examples like the HARQUITECTES firm's House 1413 or la messina | rivas firm's Angatuba House use scrap materials and stone from demolitions as the coarse aggregate for their concrete. This not only reduces construction costs but reduces waste from the demolition of old structures. In the case of House 1413, stones from a pre-existing wall were added to a cement and lime mixture to form load-bearing walls. For the Angatuba House, the cyclopean mixture was made from bricks sourced from a demolition project and then formed into the outer walls of the property.