Research Report assignment – Ancient Engineering achievements
Module:Civil Engineering 224
Name:Christiaan De Winnaar
Lecturer:Prof M Sinclair
Due date:26 April 2018
115189040957500By submitting this assignment, I Christiaan De Winnaar (17622573) declares that the entirety of the work contained therein is my own work, that I am the sole author thereof. And that authors, from which information is obtained, is given the necessary recognition.
Section A of this research report, regarding ancient engineering achievements, consists of the ancient Roman materials. The Romans are well known for their outstanding engineering feats, such as roads that were built across Western Europe, bridges spanning across wide open spaces, tunnels and aqueduct systems. Many of these marvellous engineering feats still stand today, hundreds of years later, clearly a testament of their engineering skill and ingenuity. The Roman engineers used old ideas and inventions from other ancient civilizations and improved and adapted it to their needs. Their skill inventions are still being used today.
Section B of this research report, the author investigated the construction methods and materials used by the ancient Chinese. Ancient China is a civilization that is not famous for engineering feats. Most people believe this statement and yet they are one of the most influential ancient civilizations regarding inventions and construction methods.
Table of Contents
Table of Figuresiii.
Section A: Ancient Rome1.
Construction Materials 1.
Development of construction material1.
Circumstances of discovery or refinement2.
Advantages and disadvantages4.
Relevance to today’s engineering world4.
Section B: Ancient China5.
4. Background 5.
Development of construction method6.
Circumstances of discovery or refinement7.
Advantages and disadvantages8.
Relevance to today’s engineering world8.
Section C: Discussion of the two ancient empires9.
Table of Figures TOC c “Figure” Figure 1 : Hydrated lime – volcanic ash mortar of the concrete drill core (Jackson, 213) 2.
Figure 2: Testing soil properties CITATION Inf18 l 7177 (Infonet Biovision) 2.
Figure 3: Opus caementicium used as foundations. CITATION Uni18 l 7177 (University of Southampton) 3.
Figure 4: Opus incertum (left) next to opus testaceum CITATION Uni18 l 7177 (University of Southampton) 3.
Figure 5: Opus testaceum facing above brick arch resting on travertine corbels with infill of basalt opus reticulatum. CITATION Uni18 l 7177 (University of Southampton) 3.
Figure 6: Opus mixtum: opus reticulatum in tufa above and below a band of opus testaceum. CITATION Uni18 l 7177 (University of Southampton) 3.
Figure 7: Opus vittatum mixtum CITATION Uni18 l 7177 (University of Southampton) 3.
Figure 8: The Great Wall of China CITATION Nag05 l 7177 (Nagy, 2005). 6.
Figure 9: Chinese rammed earth watchtower in Dunhuang, Gansu province CITATION Yan12 l 7177 (Yang, 2012). 7.
Figure 10: Timber Formwork and compaction of rammed earth material (Anon, n.d). 7.
Figure SEQ Figure * ARABIC 11: Holland Park Rammed Earth Eco Centre situated in Il Chester Place, London CITATION Mor18 l 7177 (Anon, ebuki). 9.
Section A: Ancient Rome
Ancient Rome was believed to be founded by two demi-gods, Romulus and Remus on 21 April 753 BCE. Due to arguments between them Romulus killed his brother in order to rule the city and he named the city after himself (J.J Mark, 2009). Other stories regarding the origin of Rome varies from person to person. The Romans put a great deal of effort into engineering. Engineering was used as a way of improving the lifestyle of the Romans even on day-to-day issues such as frequent water supply. They used the ideas of the ancient Greeks to implement their own engineering plans (historylearningsite.co.uk, 2015). They developed materials and techniques that revolutionised bridge and aqueducts’ construction, perfected ancient weapons and developed new ones, while inventing machines that harnessed the power of water. Roman engineering accomplishments generated much wealth and prosperity, improving the daily lives of Romans and helping Rome maintain its dominance in Europe and the Mediterranean for centuries (ancient.eu/Roman Engineering, 2016).
2.1 Construction Materials
Ancient Rome at its time was one of the busiest cities and in order to keep up with the high demand of busy markets, government activities, transportation and other aspects of commerce they had to construct facilities to accommodate these demands. To construct facilities they had to use materials. These materials they used were mainly stone, timber and marble. They also manufactured materials that included brick, glass and concrete. They had easy access to these materials where it was within close proximity to the city (M. Strickland, 2010). The material that will be discussed further is concrete.
2.1.1 Development of construction material
Concrete gave the Romans the ability and means to produce different types of structures. They employed skilled workers and could repeatedly formulate the mixture of concrete, providing them with a versatile and practical material which they used to expand their empire. One of Rome’s most famous figures was, Marcus Vitruvius Pollio. He was a Roman author, architect and military engineer. His concern regarding the mixture of concrete was based on the different types of sand used, which was a key component of its production. They used various types of sand: black, white, light red and dark red sands, but had to be free of any earth material. His solution in determining the best suitable sand was to rub the sand between one’s hands. The criteria were based on the fact that the sand may not leave a residue after testing. The Romans first made use of open beds which they excavated in order to obtain the sand deposits (M. Strickland, 2010). Opus caementicium or commonly known as Roman concrete was first invented in the third century BCE. They mixed volcanic dust /ash which they referred to as pozzolana with lime or gypsum, rocks and water. These materials contained elements of silica and alumina, which reacted when in contact with water which increased the strength and cohesiveness of the concrete (ancient.eu/Roman Engineering, 2016). Both these materials were collected and transported form the effluent form nearby volcano’s to the city. Due to the close proximity of these materials, transportation was fast and fairly cheap, thus increasing the production (M. Strickland, 2010). According to Sear to produce Lime mortar: quicklime (CaO) is obtained by burning limestone (CaCO3). The lime is then slaked (crumbled into water) to produce calcium hydroxide, Ca(OH)2 and is mixed with sand. On evaporation it forms crystals of CaCO3 or calcium carbonate, and so the cycle is complete. The crystals have a tendency to adhere to something rough and hard, so the addition of sand to a certain ratio actually increases the strength of the mortar. Vitruvius recommended a mixing ratio of three parts sand to two parts volcanic dust to one part of lime, which is then mixed with rocks. When adding the lime and volcanic dust / ash according to Vitruvius’ mixing ratio, the mixture reacts and forms a substance known as hydraulic cement (M. Strickland, 2010). The mixture were placed in small wooden cases and hydrated with seawater which triggered heat-releasing and chemical hardening reactions. The Romans discovered that this hydraulic cement is not only strong, but also waterproof. This gave the Romans the ability to construct structures underwater (ancient.eu/Roman Engineering, 2016).
29813252477770Figure 2: Testing soil properties CITATION Inf18 l 7177 (Infonet Biovision)Figure 2: Testing soil properties CITATION Inf18 l 7177 (Infonet Biovision)2981325191770006667519177000
Figure 1 : Hydrated lime – volcanic ash mortar of the concrete drill core CITATION Jac13 l 7177 (Jackson, 2013)
2.1.2 Circumstances of discovery or refinement
According to history from the second century BC through the second century AD the ancient world experienced the Concrete Revolution. Rome’s expansion required larger more stable structures. Before the use of concrete the Romans made use of timber and rocks to construct their structures. With the discovery of concrete and the aid of Vitruvius’s mix design Rome expanded to unthinkable heights CITATION Arm18 l 7177 (Armstrong). The concrete they used consisted of a mixture of lime, sand, volcanic ash and rocks. This mixture had the ability to be used for larger structures such as temples and basilicas and the ability to set underwater, resulting in the construction of piers, artificial harbours and aqueducts. The use of this concrete the Romans could build any type of building with no longer restrictions on the sharp angularities of cut stone and pillars. This era resulted in the construction of the most iconic structure, the Colosseum CITATION Arm18 l 7177 (Armstrong). In the beginning they only used the concrete to construct foundations, walls and vaults, but later the Romans refined their construction method and started facing the surface of the concrete. The walls were faced with stones or bricks. These brick faced concrete walls is referred to as opus testaceum. Whereas concrete faced walls faced with irregular shaped stones is referred to as opus incertum. During the time of emperor Augustus reticulate facing was used for concrete walls. Reticulate facing is a diagonal grid made up of stone pieces with a worked square face. Opus mixtum was the use of both reticulate and brick facing. During the later era of Rome the builders made use of a technique called opus vittatum, the wall facing with alternating row of bricks with small rectangular stones CITATION Uni18 l 7177 (University of Southampton).
28575001931670Figure 4: Opus incertum (left) next to opus testaceum CITATION Uni18 l 7177 (University of Southampton)Figure 4: Opus incertum (left) next to opus testaceum CITATION Uni18 l 7177 (University of Southampton)2857500-1143000-3333751936115Figure 3: Opus caementicium used as foundations. CITATION Uni18 l 7177 (University of Southampton)
Figure 3: Opus caementicium used as foundations. CITATION Uni18 l 7177 (University of Southampton)
28575001965325Figure 6: Opus mixtum: opus reticulatum in tufa above and below a band of opus testaceum. CITATION Uni18 l 7177 (University of Southampton)Figure 6: Opus mixtum: opus reticulatum in tufa above and below a band of opus testaceum. CITATION Uni18 l 7177 (University of Southampton)28575002222500-3333751965325Figure 5: Opus testaceum facing above brick arch resting on travertine corbels with infill of basalt opus reticulatum. CITATION Uni18 l 7177 (University of Southampton)Figure 5: Opus testaceum facing above brick arch resting on travertine corbels with infill of basalt opus reticulatum. CITATION Uni18 l 7177 (University of Southampton)-3333752222500
14287501893570Figure 7: Opus vittatum mixtum CITATION Uni18 l 7177 (University of Southampton)Figure 7: Opus vittatum mixtum CITATION Uni18 l 7177 (University of Southampton)142875021018500
2.1.3 Advantages and disadvantages
Roman concrete when compared to modern concrete is similar, but is made up of lime, volcanic ash, sand and rocks. The combination of the lime and volcanic ash increased the strength of the concrete with lower carbon dioxide emission than modern concrete. Roman concrete is considered stronger than modern unreinforced concrete. All of their concrete structures did not make use of metal reinforcing CITATION Pru13 l 7177 (Pruitt, 2013) . To construct the arches, vaults and domes concrete was their first choice due to the advantages it consisted. Roman concrete was exceptionally strong and were used to construct structures spanning great distances. The casting of the structures was fairly easy due to concrete could be poured into the formwork and where regarded as a plastic type material. Roman concrete did not for see any special or skilled labour to construct where as constructing timber structures they used skilled labourers. The manufacturing of the concrete was cheap, because the materials were in a close proximity to the city, reducing the transportation costs. Compared to the timber structures the Romans constructed, concrete was fireproof, safer and use less time to construct. Roman concrete consist numerous advantages, but for the Romans, the concrete was unsightly. Aesthetics for the Romans where very important and once the formwork where removed it revealed an ugly surface. This problem they overcame by covering the surface of the concrete with material with more aesthetic appealing qualities CITATION Yeg18 l 7177 (Yegul, Fikret – University of California, Santa Barbara). Despite the concrete’s advantages there were several disadvantages. The concrete had a lack of tensile strength and under severe tensile stresses the structure would collapse. The constructing of the formwork required skilled labourers and new formwork had to be constructed for each project due to the fact that on removal the formwork would be destroyed CITATION sgi18 l 7177 (Anon, sgira.org, 2018).
2.1.4 Relevance to today’s engineering world
Research teams from the laboratory of U.C. Berkeley, Saudi Arabia and Germany conducted various tests on Roman concrete and discovered the reason why Roman concrete lasted more than 2000 years. The discovery led to the conclusion that by mixing the lime and volcanic ash, to form the mortar, increased the durability and strength of the concrete. By mixing this mortar with seawater a chemical reaction took place between the lime and volcanic ash were the water molecules hydrated the lime and volcanic ash. This formed a strong bond between the materials known as a calcium-aluminium-silicate-hydrate (C-A-S-H) bond CITATION Pru13 l 7177 (Pruitt, 2013). When Roman concrete is compared to Portland cement, Portland cement does not bond as well as Roman Concrete due to the lack of the lime volcanic ash mixture in the cement. For this reason Roman concrete stayed intact for more than 2000 years and Portland cement starts to corrode after 50 years of exposure to damp air CITATION Vic16 l 7177 (Labate, 2016). One of the conclusions the research team concluded was the fact that Portland cement is one of the major contributors to the Greenhouse effect. It is estimated that each year 19 billion tons of Portland cement are manufactured. This industry produces 7% of all the carbon dioxide during one year CITATION Pru13 l 7177 (Pruitt, 2013). To produce Portland cement the mixture of limestone and clays are heated to a temperature of 1450 o C with the aid of burning fossil fuels. The Romans used a different mixture compared to our modern mixtures. They used less lime and more volcanic ash in their mixture. This resulted in a lower temperature (900 o C) required to bake the lime, using less fossil fuels and reducing the carbon footprint. According to one of the lead researchers on the team, Monteiro, Roman concrete compared to Portland cement is much environmentally friendly. The research team suggest that modern cement plants and companies should adopt and incorporate the Romans methods of producing concrete. This will result in longer lasting and more durable concrete with a “greener” effect on the environment. Monteiro propose to replace 40% of the world’s demand of Portland cement with Pozzolan (mixture of lime and volcanic ash) CITATION Pru13 l 7177 (Pruitt, 2013). This is a true testament that despite their lack of technology compared to the modern world, we can still learn from the ancient Romans.
According to Strickland concrete and bricks shared equal importance for the Roman empire. It gave the Romans flexibility, variation and durability in constructing vaults, arches and walls. Concrete made with the pozzolana cement gave it the ability to cure underwater. This allowed for the construction of artificial harbours, bridge foundations and other structures with foundations under water. The construction of these structures led to the expansion of Rome.
Section B: Ancient China
China is considered one of the oldest civilisations of the world. Ancient China dates back to the Shang Dynasty (c. 1600 – 1046 BC) more than 3000 years ago CITATION The18 l 7177 (The history of China – over 3000 years of civilisation). “In 5000 BC Chinese lived in the fertile Huang He river valley. During the 1700s BC the Shang Dynasty invaded and took over their valley. These invaders built the first permanent, organised civilisation. Since the Shang takeover, China has mostly been ruled by dynasties. The founder of the Ming dynasty brought China under one rule. Later his grandson rebuilt the capital and renamed it Beijing. He also built a palace complex called the Forbidden City. The city got his name, because only the rulers and a few officials could enter it. In 1664, the Manchus invaded China, creating the Qing dynasty. This lasted until 1911” CITATION Sum18 l 7177 (Summary: Ancient China).
5.1 Construction Methods
The Great Wall of China is a massive wall constructed in the Northern parts of China. The construction of the wall took place over several years under different dynasties. The construction of the wall began in the 11th Century BC and continued for 2000 years CITATION Kel17 l 7177 (Kelly, 2017). Unfortunately due to erosion and vandalism large pieces of the Great Wall of China was destroyed. At the time of construction the project was an idea of the leaders and is not regarded as a designed engineering project. Later on, due to the sheer size, strength, man power used and amount of materials used to construct this wall, it is regarded as one of the most extreme engineering projects ever constructed. China’s leaders decided to construct the wall to protect themselves from invaders from the north.
190501829435Figure 8: The Great Wall of China CITATION Nag05 l 7177 (Nagy, 2005).
Figure 8: The Great Wall of China CITATION Nag05 l 7177 (Nagy, 2005).
5.1.1 Development of construction method
The Great Wall of China is not a straight wall, if all the walls are considered together the total length of the wall is 21 000 km. The length is 6695 km when only considering the length from the beginning to end. The height of the wall ranges between 7 to 8 m, whereas the width of the base is 5m and the top is 4m wide CITATION Kel17 l 7177 (Kelly, 2017). Scientists estimate the total weight of the wall at 52,702,897,470 kg CITATION Ncc17 l 7177 (Nccoffice, 2017). The construction of the wall was built by three main groups of people: frontier guards, peasants and convicts CITATION Yan12 l 7177 (Yang, 2012). It is estimated that 1, 5 million men were used to construct the Great Wall CITATION Kel17 l 7177 (Kelly, 2017). Due to the size of this project the construction methods used varied from location. Each area used different methods to erect the wall. Emperor Wu Di that ruled during the Han Dynasty instructed the governors of four regions: Wuwei, Zhangye, Jiuquan and Dunhuang to be responsible for the construction of the wall sections in their areas. The Great Wall looked different from one area to another, because different materials where used for each area. The main materials that were used were earth, stone, timber and tiles. In the mountain regions large rocks were excavated to build the wall whereas rammed earth were used for the flat sections. Predominantly three types of rock were used during the construction of the Great Wall: granite (igneous rock), white marble (metamorphic rock) and white stones (sedimentary rock) CITATION Yan12 l 7177 (Yang, 2012). During this period the main construction method used was rammed earth. This method was used to construct walls; earth, lime, chalk and gravel were used as materials. Some believe, because lime did not exist at that time that the Ancient Chinese used animal or human blood as replacement for lime. They also used rice flour as mixing material. The blood and rice flour were mixed to form mortar. Temporary timber frames were erected (formwork) in a trapezium shape to increase the walls stability (Anon, n.d). At either side of the wall the formwork was erected, braced and clamped together. This method acted as a mould and could easily adopt the contours of the surrounding area. After the formwork was completed, labourers would pour moist earth material mixed with gravel in to the formwork. This process would consist of the labourers pouring the material and tamp it down with a tamping rod, layer for layer. Each layer was poured to 178mm and tamped to 127mm. This would continue until the required height was achieved CITATION Yan12 l 7177 (Yang, 2012). Near Dunhuang the labourers used different methods and materials to construct the section of wall. They used sand, rocks, tamarisk twigs and reeds. Tamarisk twigs and reeds are durable and could easily be used as a construction material. The labourers laid the Tamarisk twigs and reeds on the ground, placing the sand and rocks on top. Another layer of Tamarisk twigs and reeds were placed on top, this continued until a wall of 254 mm was achieved CITATION Kel17 l 7177 (Kelly, 2017) CITATION Yan12 l 7177 (Yang, 2012).
30861001703705Figure 10: Timber Formwork and compaction of rammed earth material (Anon, n.d).
Figure 10: Timber Formwork and compaction of rammed earth material (Anon, n.d).
37465102235Figure 9: Chinese rammed earth watchtower in Dunhuang, Gansu province CITATION Yan12 l 7177 (Yang, 2012).
Figure 9: Chinese rammed earth watchtower in Dunhuang, Gansu province CITATION Yan12 l 7177 (Yang, 2012).
5.1.2 Circumstances of discovery or refinement
During the Ming Dynasty the Emperor similar to Emperor Wu Di that ruled during the Han Dynasty divided the construction of the Great Wall between the governors of the regions. The materials they used for the construction of the wall were earth, stone, timber, tiles, bricks and lime. Bricks, tiles and lime were more regularly used compared to the Han Dynasty. The bricks and tiles were manufactured on site with the aid of kilns and the size of these bricks was 4 times larger than modern bricks today. A total of 3,873,000,000 bricks were used for the construction of the Great Wall of China CITATION Ncc17 l 7177 (Nccoffice, 2017). Due to the fact that bricks and lime were ready available the labourers could refine their technique of erecting the walls. They constructed the walls by adding two layers of wall together thus increasing the strength and stability of the wall. The wall is known as a cavity wall. The two outer walls were constructed of bricks stacked on top of stone slabs and the cavity section was filled with rocks, lime and earth. They adopted two methods of laying brick work: for a gradient of less than 45o the bricks were placed diagonally, a gradient more than 45o the bricks was constructed in a stairway pattern CITATION Yan12 l 7177 (Yang, 2012). The Han Dynasty compared to the Ming Dynasty, both used similar construction methods, the use of rammed earth to construct the walls. The difference was that the layer of the rammed earth was 76mm – 102mm thick during the Han Dynasty. The Ming Dynasty constructed a thicker layer of rammed earth 203mm thick. To save time and money the Emperor instructed the labourers to build the wall along the mountain ridges. This allowed the walls to be build lower than normal and with the aid of the steep sides of the mountain they could prevent the enemy from infiltrating their region CITATION Kel17 l 7177 (Kelly, 2017) CITATION Yan12 l 7177 (Yang, 2012).
5.1.3 Advantages and disadvantages
Advantages regarding the use of bricks and rammed earth were, it increased the strength and stability of the wall. The method of using the rammed earth and bricks was faster comparing to other methods that were used during that era. Due to the fact that they constructed the Great Wall of China according to the contours of the area gave them the ability to reduce the construction time and money. By building the wall along the ridges of the mountain resulted in the construction of lower walls. The walls integrated with the steep sides of the mountain gave the Chinese the military advantage over their enemies. With every construction project there were disadvantages: labourers worked in tremendous working conditions, this resulted in a high fatality among the labourers. The transportation of materials to the construction sites was also an obstacle the Chinese had to overcome. They used manpower, tools and animals to transport the material to the top of the mountain. The men and animals would carry the material on their backs. Later on they made use of advanced tools were they used rods, ropes and pulleys to lift the material up the mountain CITATION Yan12 l 7177 (Yang, 2012).
5.1.4 Relevance to today’s engineering world
Scientists discovered that the strength of rammed earth that consists of sand, gravel and clay depends on the water content. Due to the type of materials used for this mixture, it is regarded as a “green construction material” CITATION Ano09 l 7177 (Anon, The Telegraph, 2009). Rammed earth is the method were a mixture of sand, gravel and clay which is poured in layers in formwork moistened and tamped with a tamping rod or tamping device CITATION Yan12 l 7177 (Yang, 2012). This method was discovered by the Ancient Chinese were they constructed sections of the Great Wall of China. Due to its “green” characteristics it’s been widely used in projects today making it environmentally friendly and reducing the demand of Portland cement, which contributes to 7% of the world’s annually carbon dioxide emissions. These projects include the Alhambra palace in Granada in Spain, the Eden Project, a visitor attraction situated in Cornwall and the Holland Park Rammed Earth Eco Centre situated in IL Chester Place, London. Scientists conducted various experiments on rammed earth applying external pressures to the material modelling the pressures in a wall. Their tests concluded that the strength of the material was due to the moisture inside the material. The material has a sandcastle effect- after construction the material is left to dry, but retains small amounts of moisture which increases the material’s strength over time CITATION Ano09 l 7177 (Anon, The Telegraph, 2009). According to Tom Morton, project officer at Earth Building UK ; Ireland, “By understanding more about this we can begin to look at the implications for using rammed earth as a green material in the design of new buildings and in the conservation of ancient buildings that were constructed using the technique” CITATION Ano09 l 7177 (Anon, The Telegraph, 2009).
Figure SEQ Figure * ARABIC 11: Holland Park Rammed Earth Eco Centre situated
in Il Chester Place, London CITATION Mor18 l 7177 (Anon, ebuki).
The construction of the Great Wall of China could well be the most significant engineering project ever constructed in the history of mankind. This project is the biggest Civil Engineering project, but also the project that took the longest to complete. Constructing a project of this magnitude today would cost billions of rand, making it the most expensive project, but with modern technology the construction time would be shorter.
Section C: Discussion of the two ancient empires
When comparing the two ancient civilisations, ancient Rome and ancient China, it is possible to say that construction materials and construction methods used improved over the past centuries. Construction projects that took place centuries ago have similarities to toady’s construction projects. Materials and methods used during the ancient era are still being used, only improved and modernised. One challenge associated with these construction projects during the ancient era and during today’s modern era is the management of these projects. The following aspects regarding civil engineering: construction methods, materials, time management, budget, labourers and environmental issues are still applicable during the ancient era as well as today. The aspects need to be addressed in order to ensure a successful and profitable outcome.
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