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Etymology[ edit ] The word concrete comes from the Latin word "concretus" meaning compact or condensed the perfect passive participle of "concrescere", from "con-" together and "crescere" to grow. Prehistory[ edit ] Small-scale production of concrete-like materials dates to BC, pioneered by the Nabataea traders or Bedouinswho occupied and controlled a series of oases and developed a small empire in the regions of southern Syria and northern Jordan.
They discovered the advantages of hydraulic lime, with some self-cementing properties, by BC.
They built kilns to supply mortar for the construction of rubble-wall houses, concrete floors, and underground waterproof cisterns.
They kept the cisterns secret as these enabled the Nabataea to thrive in the desert. German archaeologist Heinrich Schliemann found concrete floors, which were made of lime and pebbles, in the royal palace of TirynsGreece, which dates roughly to — BC.
Its widespread use in many Roman structuresa key event in the history of architecture termed the Roman Architectural Revolutionfreed Roman construction from the restrictions of stone and brick materials.
It enabled revolutionary new designs in terms of both structural complexity and dimension. Laid in the shape of archesvaults and domesit quickly hardened into a rigid mass, free from many High performance concrete the internal thrusts and strains that troubled the builders High performance concrete similar structures in stone or brick.
First, its mix consistency is fluid and homogeneous, allowing it to be poured into forms rather than requiring hand-layering together with the placement of aggregate, which, in Roman practice, often consisted of rubble.
Second, integral reinforcing steel gives modern concrete assemblies great strength in tension, whereas Roman concrete could depend only upon the strength of the concrete bonding to resist tension. The Baths of Caracalla in Rome are just one example. Many Roman aqueducts and bridges, such as the magnificent Pont du Gard in southern France, have masonry cladding on a concrete core, as does the dome of the Pantheon.
Middle Ages[ edit ] After the Roman Empire, the use of burned lime and pozzolana was greatly reduced until the technique was all but forgotten between and the 14th century. From the 14th century to the midth century, the use of cement gradually returned. The Canal du Midi was built using concrete in This third Eddystone Lighthouse pioneered the use of hydraulic lime in concrete, using pebbles and powdered brick as aggregate.
His son William continued developments into the s, earning him recognition for the development of "modern" Portland cement. The first concrete reinforced bridge was designed and built by Joseph Monier in .
Composition[ edit ] Many types of concrete are available, distinguished by the proportions of the main ingredients below. In this way or by substitution for the cementitious and aggregate phases, the finished product can be tailored to its application.
Strength, density, as well as chemical and thermal resistance are variables. Aggregate consists of large chunks of material in a concrete mix, generally a coarse gravel or crushed rocks such as limestoneor granitealong with finer materials such as sand.
Cementmost commonly Portland cementis associated with the general term "concrete. One of the most familiar of these alternative cements is asphalt concrete. Other cementitious materials, such as fly ash and slag cementare sometimes added as mineral admixtures see below — either pre-blended with the cement or directly as a concrete component — and become a part of the binder for the aggregate.
To produce concrete from most cements excluding asphaltwater is mixed with the dry powder and aggregate, which produces a semi-liquid slurry that can be shaped, typically by pouring it into a form.
The concrete solidifies and hardens through a chemical process called hydration. The water reacts with the cement, which bonds the other components together, creating a robust stone-like material.
Chemical admixtures are added to achieve varied properties. These ingredients may accelerate or slow down the rate at which the concrete hardens, and impart many other useful properties including increased tensile strength, entrainment of air and water resistance.
Reinforcement is often included in concrete. Concrete can be formulated with high compressive strengthbut always has lower tensile strength. For this reason it is usually reinforced with materials that are strong in tension, typically steel rebar.
Mineral admixtures have become more popular over recent decades. The use of recycled materials as concrete ingredients has been gaining popularity because of increasingly stringent environmental legislation, and the discovery that such materials often have complementary and valuable properties.The global ultra-high performance concrete market is majorly driven by the increasing demand for high strength, and durable concrete in applications such as .
Ultra High Performance Concrete, or UHPC, is a new material offering new application possibilities. This material has exceptional features: high strength, high .
Ultra high performance concrete (UHPC) is a milestone in concrete technology and application. It permits the construction of both more slender and more durable concrete structures with a prolonged service life and thus improved sustainability.
This book is a comprehensive overview of UHPC - from the principles behind its production and its. These low-shrinkage, high-fiber mixes are the proper diet for high-performance concrete floors, slabs, and toppings. A high-paste, high-shrinkage mix will not result in minimal cracking and curling.
An athletic concrete mix allows us to place contraction joints at about 25 feet for 6-inch-thick slabs. High Performance Concrete Plant Portable – regardbouddhiste.com China Good Performance Mdhb Good Performance Mdhb Series Portable Asphalt Mixing Plant 20tph Picture From A Unique Industrial Equipment Co., Mobile Concrete.
High Performance Mobile Concrete . Ultra-High Performance Concrete (UHPC), also known as reactive powder concrete (RPC), is a high-strength, ductile material formulated by combining portland cement, silica fume, quartz flour, fine silica sand, high-range water reducer, water, and steel or organic fibers.
The material provides.