Principles of Cement and Concrete Composites

More advanced techniques have been proposed for construction purposes and improvement cement because of the global sustainability demand. Alongside the integrations of positive policies, emission reductions for all infrastructural projects can be achieved when there shall be swift scale-up in the novel cement use. The book explores techniques such as self-consolidating and advanced nano cements, green cement, and steel fiber reinforcements and how they contribute to construction cost reductions and environmental sustainability. In comparison with the traditional cement, improved multifunctional nano-engineered concretes exhibit advanced functionalities. They for example have up to 146% and 76.5% respective compressive and flexural strengths. They also have improved electrical and thermos-mechanical performances with considerable declines in absorption of waters of about 400%. Technologies of modern engineering aim at generating multifunctional and ultra-high performance concrete substances because of the increased demands for cost-effectiveness, sustainability, and durability. Such building materials are marked by long-term performances and advanced mechanical characteristics. Also, they incorporate characteristics that promote different uses making them sustainable for future applications. Advanced concrete composites are important in multifunctional uses such as in chemical and marine exposed environments because of their high corrosion resistance, affordability, high durability, and lightweight nature. Composite materials (combinations of aggregates) offer an in-built mixture of toughness and stiffness with corrosion resistance and lightweight properties. Such materials are obtained from various compositions with different physical and chemical characteristics. Combinations of such concretes give special capability that gives composite materials an advantage over other improvement methods. Major classifications are explained below:

To begin with, the current study reviews the cement hydration state in the nanomaterial modeling presence. It is important to comprehend that nanotechnology is an active research part across the globe. In particular, the idea began after the carbon nanotube inventions, which is used in some areas that include machine components, electronic, and bio-mechanic. With that said, the advent of nanotechnology contributes to the development of materials which may be used to designs of high-performance concrete mixes. It is important to comprehend that nanosilicas react with calcium hydroxides to establish more of the strengths carrying the cement structures, calcium silicate hydrates. The paper in question indicates the development of correlations to differentiate the advantages when utilizing various sizes of nanosilica in cement paste. In fact, the mechanical characters of concrete substances count to a significant level on structural components as well as concepts that are adequate on micro-and nanoscales. The sizes of phases of the calcium silicate hydrates are the fundamental elements responsible for strengths and other features of cementitious substances, which depend on the ranges of few nanometers. Specifically, the C-S-H structures are like clays with thin solid layers separated gel pore with adsorbed and interlayer water.

The cement industry constitutes a severe threat to ecology, including through its negative impact on the climate, due to the high level of carbon dioxide (CO₂) emissions associated with it. Given that this is the case, the modern world is looking for alternatives in order to preserve the environment for future generations. The eventual goal, therefore, is for industry to stop emitting carbon into the air. Many effective steps can be taken by industry leaders to achieve lower carbon emission targets to improve local ecological systems. This paper discusses the ways in which CO₂ is measured and alternatives to the standard methods through which hydraulic cement is produced in order to reduce CO₂ emissions. The benefits of using alternative methods, specifically relying on kilns and/or synthetic fuels, are identified and discussed. An assessment of the conditions needed for the industrial production of new cementitious systems in which clinker-calcined limestone and low-carbon clay are used is also presented. Additionally, an account of the clinkerization process of low-carbon cement (LCC) is provided. The new materials are shown to meet global standards in applications such as the production of hollow concrete blocks and precast concrete. In a comparison between Portland cement and the new materials, no major differences were found in either the mechanical or rheological features. An environmental ternary cement assessment is also reported that includes comparisons with other industrially blended cements. LCCs are shown as having the ability to reduce carbon emissions from cement production by more than 30%.

It is possible to enhance the ability of crack control and inherent brittleness of ordinary concretes by integrating discrete fibers into concretes. Fiber-reinforced concretes are acknowledged as high-performance building materials due to their high levels of toughness under tensile and compressive loads. It is therefore broadly applied in precast structures, bridges, tunnels, and high-rise buildings. Societal demand has raised the requirements for advanced fiber-reinforced concrete composites with multifunctionality and ultra-high performance such as self-regulating, self-clearing, self-sensing, and self-healing. These special issues focus on the emerging ideas that permit the development of improved or new fiber-reinforced concrete composites and characterizations of the features of advanced fiber-reinforced concretes. Original research papers and authoritative review journals explain the present findings in the advanced fiber-reinforced concrete composite field are anticipated to cover a variety of topic. The potential topics include, but are not restricted to structural applications of advanced fiber-reinforced concrete composites, fiber-bridging behaviors, multiple micro-cracks, strain-hardening behaviors, property characterization, nanofiber reinforced concrete composites, advanced fiber-reinforced cement-free composites, ultra-high performance fiber-reinforced concretes, multifunctional fiber-reinforced concrete composites, and advanced fiber-reinforced concrete composites.

There have been multiple developments and improvements in concrete technologies that had impacts on structural system in recent years. The cement mixtures are used with silica fumes in place of steel fibers and silica fumes (pozzolanic materials) in the form of superplasticizers and are classified as ultra-high-strength concretes to enhance the slab structural behaviors. This chapter explains current study literature associating with reactive powder concrete (RPC). So far, there are no available official design codes on RPC. Current information associated with the present topic can be classified according to the historical background and development of RPC and its mechanical properties and durability.

Recycled concrete aggregates (RCAs) are utilized as recycled concrete wastes in the present structures of green concretes. The RCAs are sustainable concrete wastes that in the long run can substitute the demands for natural aggregates, processes that would in turn result to their preservations. The RCA use in concretes as full or partial substitutions of natural coarse aggregates (NCAs) is increasing interests in the building and construction sector because it minimizes the demands for natural aggregates. Besides, RCA utilization minimizes the adverse environmental impacts of virgin aggregate extractions from the natural resources and results in potential solutions to the ecological problems caused by concrete wastes. The aim of this paper is to critically review recycled concrete aggregates to produce ultra-performance concrete structures. This chapter provides a detailed review on RCAs application in concretes on the basis of the experimental information available in the published studies. In this chapter, the most significant chemical, physical, and mechanical features of recycled concrete aggregate are explained. Nevertheless, more focus has been given to explain the RCA effects on the concrete durability and fresh and hardened characteristics of the concrete. Also, this research identified the disparities existing in the current knowledge state on recycled concrete aggregates and natural concrete aggregates and offers some suggestions for future studies.