CHAPTER 1 INTRODUCTION
1.1 General
Nowadays, the basic construction material is concrete which is used more than any other man-made material in the world to make pavements, architectural structures, foundations, roads, bridges, etc. Concrete is a construction material composed of cement (commonly Portland cement) as well as other cementitious materials such as fly ash and slag cement, aggregate (generally a coarse aggregate such as gravel, limestone, or granite, plus a fine aggregate such as sand), water, and chemical admixtures (such as accelerating admixtures, air-entraining admixtures, water-reducing and set-controlling admixtures, finely divided admixtures, polymers for polymer-modified concrete, superplasticizers, silica-fume admixture for high-strength concrete, corrosion inhibitors, etc). Concrete solidifies and hardens after mixing with water and placement due to a chemical process known as hydration. The water reacts with the cementitious material, which bonds the other components together, eventually creating a stone-like material.
The science of mixing the ingredients to make concrete is called mix design. The selection of mix proportions is thus, simply, the process of choosing suitable ingredients of concrete and determining their relative quantities with the object of producing as economically as possible concrete of certain minimum properties, notably strength, durability, and a required consistency. It can be seen then that mix selection requires both knowledge of the properties of concrete and experimental data or experience.
Because the current system uses a trial-and-error type of concrete mix proportion design, systemizing the design process is difficult. The different local materials and mixing cond...
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...ity results obtained using the one-parameter and two-parameter Bayesian methods as well as ACI’s normal distribution probability method performed for verification are presented.
Chapter 4 contains the methodology performed by the author. In contrast to much previous design work in the area, the design approach is deliberately incremental to facilitate user familiarity and systematic evaluation.
Chapter 5 reports the applications of the proposed PBMD procedure in the previous chapter to concrete mix proportion for normal performance requirements.
Chapter 6 reports the applications of the proposed PBMD procedure in the previous chapter to concrete mix proportion for high performance requirements.
Chapter 7 concludes the thesis by summarizing the main findings and contributions from the thesis. Limitations of the research and routes for further work are presented.
The reader will find this paper has two main sections and a closing. The first will provide the previous discussed critical analysis and then a brief summary of the overall value of the systematic research. The second provides the current author’s reflection on his approach to his dissertation.
The author uses notable authors such as John Demos, Mary Beth Norton, Carol Karlsen, Paul Boyer and Stephan Nissenbaum to evaluate the current literature on the topic. Furthermore, the author writes for the contemporary somewhat educated reader. His work references and relies on the work done by writers that are known within this topic.
This paper will illustrate a brief summary of two chapters and give a critical analysis of the readings. In addition I would conclude the paper by briefly discussing my opinion on the readings.
I have come up with this thesis by gathering information from online and what I have seen and read about over the years. Below are the areas used and addressed from the Thesis Checklist:
In the following synthesis essay the author found various sources on the same topic and used certain parts of those sources to support the thesis statement.
The above is provided so the student has a better idea of the focus of the paper. The complete paper begins below.
ement occupies approximately 50% of the mixed concrete volume and is responsible for physiomechanical properties of concrete. Cement production is essential to infrastructure and building construction, creating demands in very large quantities. Energy resources invested in the production process and resulting greenhouse gas emissions have become problematic. The cement production process has become among the world’s largest anthropogenic sources of carbon dioxide emissions, contributing to approximately 5% of global anthropogenic CO2 emissions, (WBCSD, 2009). Increased pressure is being placed on the industry to reduce CO2 emissions, owning to awareness regarding sustainability....
Concrete is one of the world’s most popular construction materials. Some six billion tonnes of concrete is produced each year in the world, making it approximately one ton of concrete for every human being per year (Fardis, 2012, p.116). However, the lifecycle of concrete does not make it the most sustainable building material at the moment. Because of limited natural resources, concerns over green house gases, and landfill problems, concrete production is being cut-back, or at least cannot be increased to keep up with population increase. In this essay, I will look at what makes concrete an unsustainable material and possible solutions to make concrete a more sustainable material.
Concrete can be an excellent choice for paving driveways, parking lots, walkways and other areas. When many customers begin considering having concrete installed, they often ask about the best thickness for the slab. Although many municipalities have established codes that require a specific minimum thickness, in some cases, the actual number may be higher than the one required by the code. Therefore, a concrete contractor must consider a variety of factors before deciding on how thick to make the slab.
Now a days HPC is expensive than conventional concrete. It require additional materials in some quantities as to meet specified performance.These additional materials are cement,silica fume,...
In this report, we will introduce and illustrate on precast concrete, pre-stressed concrete, ready-mix concrete, reinforced concrete, terrazzo and Urbanite in details.
Most people may not realise but concrete plays a vital part in our lives daily. It shapes and creates the built environment in which we are surrounded by, such as schools, bridges, roads, housing, hospitals, dams and so much mores. Concrete is the most used man made material in the world, averaging around 3 tonnes annually for each person. In comparison with other building materials such as wood, steel, plastic and aluminium, over twice as much concrete is used globally than any of these materials. It is the material choice of most purposes due to its strength, durability, thermal mass and its cost.
The slides for the presentation that accompany this paper can be found in the appendices.
Opus caementicium or Roman concrete is a synthetic construction substance that’s composed of an aggregate, a binding agent, and water. In Rome’s case, as discovered by UC Berkley with the extensive analysis of a sample of Roman concrete taken from a breakwater in Italy’s Pozzuoli Bay it was developed by using lime and volcanic rock which formed a mortar, the mortar and volcanic rock were then packed into wooden forms and when seawater was added a chemical reaction occurred, bonding everything together to create concrete (History, 2013). It is uncertain when Roman concrete was developed, but it was clearly in widespread and customary use from about 150 BC; some scholars believe it was developed a century before that.