by As a structural material, stone can form different structural systems, such as slab column system, beam column system, wall bearing structural system, arch structure and so on.
Stone has the advantages of high compressive strength and good durability, which determines that stone is mainly used in pressure parts and parts resistant to natural environment erosion, such as walls, columns and foundations.
Sometimes it is also used as building structural components such as roof panels and beams.
Stone has been used as a structural material for a long time, and the method of connecting stone components has been developing and changing in the long application history.
Structural system and component form of stone 1: stacking refers to the connection of stone without any bonding materials, which makes the overall stability between stones only through the self weight of stone or the bite and stacking of materials.
At first, the stacking method was mainly used in stone wall masonry.
It can be roughly divided into three types: (1) it is built by polygonal stones (Fig.
1), and some stones are also roughly processed to make them bite each other (but the walls built with boulders, although carefully assembled, are generally rarely carved and do not use mortar); (2) Adopt neat staggered masonry method (Fig.
1); (3) A more regular rectangular stone wall, that is, a wall made of chiseled stones in layers (the joints between stones in the same layer are not necessarily vertical), as shown in Figure 1.
Figure 1: masonry methods of early stone walls there are many kinds of pebble wall masonry methods in Nanxi River in Jiangsu and Zhejiang regions of China: rubble masonry, herringbone wall, free herringbone wall, etc.
Generally, the foundation is laid with large rubble, and then built with two layers of internal and external skin, and the score is gradually collected upward.
There is no mortar, plaster or other filling materials between the stones.
It is made by natural mutual extrusion with superb technology and the size and shape of the stones (as shown in Figure 2).
The walls of stone houses in Guizhou, China are made of random stone slabs, like bricks, into a wall about 40 cm thick (as shown in Figure 2).
In the early days, when the stone was used as the roof, the whole stone was mostly used as the roof slab, and then the roof formed by overlapping stone slabs appeared (as shown in Figure 2).
Figure 2: the form of stone wall and stone roof in China.
The stone dome can be built by stacking and picking out stones.
The size of the stone slab used to build the dome is relatively large, and each stone is arranged at a certain angle with the stones in the lower layer, and gradually shrinks inward.
In this way, each layer forms a polygon, and the central opening is reduced to close layer by layer to form a stacked dome.
The internal shape of the dome formed by this method is like a rose (Fig.
3).
Although it is incomplete, it is unique.
Figure 3: the tomb ceiling built by stacking and picking out.
In the 1st century BC, 2: connecting stone with bonding material – mortar.
In ancient China, lime slurry, lime mortar plus glutinous rice juice and lime clay mortar were used to bond stone.
The bonding materials of modern stone masonry also include stone mortar, lime cement mixed mortar and cement mortar.
Mortar masonry wall includes random stone wall and whole stone wall.
The random stone wall is made of stones of different sizes, shapes and uncut.
The wall surface is uneven.
According to the shape of stones, there are stone walls (as shown in Figure 4), tiger skin walls (as shown in Figure 4) and stone walls (as shown in Figure 4).
During the masonry of random stone wall, the corner or wall head shall be built first, and then the stones shall be built from both ends to the middle.
The size of the stones shall be matched, the large surface (seat surface) shall be downward, the facing surface (relatively neat surface) shall be outward, the inclined mouth shall be inward, and the upper and lower joints shall be staggered.
Stone joints must be filled with cement mortar or mixed mortar.
The whole stone wall is made of processed stones with regular shape.
The whole stone size is 600-1200mm long, 200-600mm wide and 150-400mm high.
The wall is 250-400mm thick and the mortar joint is 3-6mm thick.
During masonry, stones shall be overlapped with staggered joints.
Figure 43: stone components pinned by connectors have been widely used everywhere.
The ancient Egyptians used wooden dovetail pins to connect the layers of stones; In the Mycenaean period, people used copper pieces to fix the decorative surface; The Greeks used pin connectors in structural components, changed copper parts into iron products (Fig.
5), and assisted with the method of pouring lead from the east to fix the iron pins in stone components.
Of course, expensive metal pins can only be used in the most important buildings.
Figure 5: the stone pin connects the huge column of Parthenon temple in ancient Greece.
The bottom diameter is 2M and the height is 10m.
The tall stone columns are composed of stone drums 0.9 meters high.
The top layer and the bottom layer of the stone column are deformed.
The columns and drums are only chiseled and matched around, with small holes in the center and connected with wooden pins in the middle (as shown in Figure 6).
Figure 6: the construction method of the inclined corner column of the Parthenon temple column.
The stone work in China’s architectural construction.
The iron work connection in the process includes “pulling” (as shown in Figure 7), using “silver ingot”, also known as “head hook” (as shown in Figure 7), and using “picking curium” (as shown in Figure 7).
Usually, the surface of the stone work is chiseled into a nest according to the shape of the iron work, and the iron work is placed well.
The spare part is filled with mortar or alum water.
The particular method is to fill with brine slurry or molten iron.
Figure 7: Iron connection in stone work in China 4: Post Tensioning Technology stone is very strong under pressure and can withstand great pressure.
Therefore, engineer Peter wise combined stone masonry with tensile steel cable and invented the post tensioning load-bearing technology of stone.
Later, wise improved the post tensioning method by inserting steel bars into the stone and tightening the steel bars to press the stones tightly together.
Renzo Piano used this technique in the later designed Padre piopilgrimage Church (see Figure 8).
Pre pressing stones with post tensioning method can reduce the risk of cracking of stones under tension, and the stone arch connected by post tensioning method can also meet the seismic fortification requirements of the area where the church is located.
Figure 8: Padre piopilgrimage church 5: metal frames connect stones.
Cages made of metal wires are used as containers, which are filled with stones to form a stone basket..
