Chinese architecture is considered an important constituent of world architecture. During its development, it formed, bit by bit, into a style which featured timberwork combining stone carving, rammed earth construction, bucket arch buildings and many other techniques. Builders in ancient China were considered as craftsmen with a special professional status. The scale of a set of buildings became extensible because of the characteristics of Chinese ancient buildings. Many ancient Chinese houses were built of wood and so were pagodas. Wood was used to construct primary structures of the building such as columns, beams and roofs. The wooden structures possessed great physical strength that they could withstand earthquakes and other vagaries of nature. The Great Wall of China is one of the celebrated structures and it was generally made of wood, stones and rammed earth many decades before the emergence of bricks.
Tireless Chinese laborers created many architectural and engineering marvels such as the Great Wall of China, Forbidden City and the Mausoleum of the First Qin Emperor. The concept of open building in China has been in development since about 7,000 years ago. In this ancient building, walls are not part of the supports; they are very thin or even replaced by doors, windows, or other furniture. They established relationships with the owners and users of the buildings they constructed directly and sometimes took responsibility for certain constructions all their lives (Du, 1993).
Characteristics of Ancient Chinese Buildings
The traditional Chinese building structure can be divided into two parts: Large Wood Work for the main building structure and Small Wood Work including an all fit-out construction (Jia, B 2001). Large Wood Work is the primary structure composed by beams, columns, bracket sets, and roofs, which are connected together without any nails. The weight of the upper floors and roof is concentrated and transferred down to the beams and columns using bracket sets. All the parts belonging to the Large Wood Work can be changed independently.
A family of five members can be accommodated in the primary courtyard of one "jin" which is the collection of homes erected in the area around one courtyard. With the development of the family, several units can be added along the north-south axis or west-east axis. If the land is enough, this expansion can be endless while always maintaining a temporarily completed form. Such kind of phenomenon can also be found in some other types of residential buildings.
The best manifestation of the flexibility of ancient buildings is their functional adaptability, the number of which is much more than the above two in the historical records. It is another character of Chinese traditional buildings: neutrality of space, which means a room or a set of rooms, can be multi-functional (Jia, 1998). There are two kinds of neutrality: several functions overlaying in one space and one function replacing another completely.
Materials used in ancient Chinese construction
Rammed earth, also known as taipa is a technique used in the building of walls using the raw materials of earth, chalk, lime and gravel. It is an ancient Chinese building method that has seen a revival in recent years as people seek more sustainable building materials and natural building methods. Rammed earth walls were simple to construct, incombustible, thermally massive, very strong and hardwearing. Conversely they can be labor-intensive to construct without machinery (powered rammers), and if improperly protected or maintained they are susceptible to water damage. The availability of useful soil and building design for the local climatic conditions are the factors which favor its use (Kendall, 2000).
Building a rammed earth wall, involves a process of compressing a damp mixture of earth that has suitable proportions of sand, gravel and clay sometimes adding a stabilizer, into an externally supported frame, creating a solid wall of earth. Historically, animal blood and lime were used to stabilize the material. However, today rammed earth construction uses lime, asphalt emulsions or cement.
Ancient Chinese used a super-strong mortar made from sticky rice, the delicious "sweet rice" that is a modern mainstay in Asian dishes to fill gaps between bricks, stone blocks and other construction materials Pan (2005), and colleagues note that construction workers in ancient China developed sticky rice mortar about 1,500 years ago by mixing sticky rice soup with the standard mortar ingredient.
The earliest extant bricks were used to build a pagoda 40 meters tall. It was called the Songyue Pagoda in Dengfeng Country; this curved, circle-based pagoda was built in 523 during the Northern Wei Dynasty, and has survived for 15 centuries. Brick was mainly used in the construction of external walls in houses and much more used in the construction of the Great Wall of China. Stone is naturally occurring and can be shaped by use of various tools into desired shapes and sizes. It was dug from miniature quarries, shaped into desired sizes then transported to site of construction. The earliest large-scale stone pagoda is a Four Gates Pagoda at Licheng, Shandong, built in 611 during the Sui Dynasty. Like the Songyue Pagoda, the Four Gates pagoda features a spire at its steeple, and the pavilion style was used in its building.
For any building to be billed to its expectation, certain laid out processes had to be followed before during and after its construction depending on the major material being used, In a situation where rammed earth was used, a temporary frame was first built, usually out of wood or plywood, to act as a mold for the desired shape and dimensions of each wall section. Historically, compression was done by hand using a long ramming pole though it was manually involving. Modern construction is more efficient since it employs the use of pneumatically powered equipment.
Once the wall was complete, it was strong enough that the frames could be immediately removed. Afterwards, the Small Wood Work or infill parts was produced and affixed to the main structure to complete the building. As all the size of parts is confirmed by a certain modulus unit, except for some special requirements, all the parts could be made offsite. The building was then erected by stages with separate sets of columns, beams and purlins in between every two storey's. Joining these together were dougong brackets of 50-60 kinds, which would hold the huge wooden structure together in an integral piece, strong and magnificent, without the help of a single piece of metal (Li, 1999).
Real Life Examples of Ancient Chinese Constructions
The Chinese were already familiar with the techniques of wall-building by around the 8th century B.C.E. During the militaristic States era from the 5th century B.C.E to 221 B.C.E, the states of Qi, Yan and Zhao built far reaching walls to defend their borders. Qin Shi Huang occupied all rival states and united China in 221 B.C.E, founding the Qin Dynasty. Seeking to enforce centralized rule and to prevent the renaissance of feudal lords, he ordered the destruction of parts of the wall that alienated his empire along the previous state borders and ordered the construction of a new wall to join the remaining walls along the empire's northern borders in order to protect the empire against attacks by the Xiongnu people. Thus was born The Great wall of china (Xu, 2009).
The Great Wall of China was mainly built from stones, wood and rammed earth, before the use of bricks was invented. Later on during the Ming Dynasty, bricks were profoundly used in many parts of the wall, materials such as tiles, lime, and stone were also used. Accordingly, rectangular cut stones were mainly used to build the foundation, brims, and gateways of the wall. Battlements lined the uppermost portion of the vast majority of the wall, with defensive gaps a little over 30 cm tall and about 23 cm wide (Pan, 2005).
The base was either on top of an underground room or on the ground and supported the whole structure. Brick and stone were used to construct them and most of them were between ten and twenty centimeters high and due to the vagaries of the environment soon they became indistinct and unrecognizable from the ground such that it looked like the pagoda was built on the ground without a base (Li, 1999). The main part of the pagoda, the body, varied depending on the architectural style applied in its construction. They could be solid or hollow. Solid pagodas were filled with bricks, stones or rammed earth. Occasionally, a wooden framework was installed inside a solid pagoda to strengthen the bearing capacity of outreaching parts of the pagoda. On the whole, however, the inner structure of a solid pagoda was relatively simple.
Where the Pagoda was built with brick exteriors and wooden interiors, the brick walls formed the body of the pagoda like a hollow tube. Openings were created when building the brick walls for laying the floor slabs and positioning up door and window frames. Some of the time, pillars were put up at the corners so as to prop up the flooring above. In most instances twisting set of steps were built beside the walls. The number of storeys in a pagoda of this type usually corresponded to the positions of doors and windows and levels of eaves on the outside (Yu, 2005). The steeple is very significant in the structure of a pagoda, it is the tip of the building and whether the pagoda's roof is hexagonal, square, round, or octagonal, the sheathing, rafters and tile ridges all come to one point, the steeple. All these parts are fixed to the steeple in order to stabilize the roof structure and prevent rain from leaking into the building (Li, 1999).
In today's engineering design and construction, all the buildings and the dimensions of the rooms are designed based on their functions. The location of every function is clearly separated, and sometimes even the position of every piece of furniture is already fixed at the design stage. Almost all the parts are immobile to the structure so that they cannot be renewed. The information makes the current buildings and constructions very suitable for a single function with only one dimension but without any adaptability to future development. Furthermore, the service life of a building is calculated through the earliest aging parts rather than the main structure, which may be used much longer. Additionally, the distant relationship between the engineering designers and users leads to a trend wherein designers and developers are more likely to pursue superficial beauty than practicability, or to attend to the current issue rather than future development. Thus, today's architectural designers should, at least, partly take responsibility for the construction waste.
For nearly 5,000 years, Chinese traditional buildings and constructions have been distinct from other kinds of constructions all over the world. On the aspect of structure and construction, its three-level structure makes it flexible and extensible. This structural character provides functional adaptability or multifunctional adaptability. The particular regulations on scales and sizes of constructions in the Qing Dynasty further led the construction production to the direction of standardization.