Construction Materials: Concrete PDF

CONSTRUCTION MATERIALS: CONCRETE Prepared by : Engr. Kent Dominic Armateo CONCRETE Concrete is a composite material composed of aggregate bonded together with a fluid cement that cures to a solid over time...

CONSTRUCTION MATERIALS: CONCRETE Prepared by : Engr. Kent Dominic Armateo CONCRETE Concrete is a composite material composed of aggregate bonded together with a fluid cement that cures to a solid over time. Concrete is the second-most- used substance in the world after water and is the most widely used building material. When aggregate is combined with cement and water, it forms a fluid slurry that can be poured and moulded into shape. The cement interacts with the water in a process known as hydration, which hardens it over several hours to form a strong matrix that binds the ingredients together creating a long-lasting stone-like substance with several applications. CLASSIFICATION OF CONCRETE Concrete can be classified into the following : 1. According to Binding Material used in Concrete 2. According to Design of Concrete 3. According to Purpose of Concrete CLASSIFICATION OF CONCRETE ACCORDING TO BINDING MATERIAL Cement Concrete – a type of concrete in which cement is used as a binding material to bind sand as fine aggregate and gravel as coarse aggregate. Cement concrete is commonly used in Buildings and other important engineering works where strength and durability is of prime importance. CLASSIFICATION OF CONCRETE ACCORDING TO BINDING MATERIAL Lime Concrete – this type of concrete consists of fine aggregates, coarse aggregates and Hydraulic Lime as the binding agent. Generally used in restoration and conservation work, as well as in some construction applications, such as soil stabilization and plastering. CLASSIFICATION OF CONCRETE ACCORDING TO DESIGN OF CONCRETE Plain Cement Concrete – this type of concrete has no reinforcing bars and commonly used in foundation works as well as flooring of building. It is strong in compression but weak in taking tensile stresses. CLASSIFICATION OF CONCRETE ACCORDING TO DESIGN OF CONCRETE Reinforced Cement Concrete – this type of concrete is actually very similar to PCC in terms of materials used. The one big difference in its composition is the addition of steel rebar. By casting the wet cement around reinforcing steel bars, the resultant composite material has much more strength under tension while keeping the properties that make PCC so effective. CLASSIFICATION OF CONCRETE ACCORDING TO DESIGN OF CONCRETE Prestressed Concrete – this is a form of concrete where initial compression is given in the concrete before applying the external load so that stress from external loads is counteracted in the desired way during the service period. CLASSIFICATION OF CONCRETE ACCORDING TO PURPOSE Fast-Setting Concrete - is a pre-mixed variety and hardens in only 20 to 40 minutes It bonds well with wood, brick, metal, and plastic. Out of the many different types of concrete on the market, exterior contractors often use this for fence and pergola post settings. Best For : Post setting for fences, landscaping, and mailboxes CLASSIFICATION OF CONCRETE ACCORDING TO PURPOSE Crack – Resistant Concrete – generally use for sidewalks, patios, floors, steps, or anywhere else where a long-term, crack- free finish is crucial. As the name implies, using crack-resistant concrete reduces the chances of cracking due to ground movement or inadequate reinforcement. Best For : Steps, walkways, driveways, patios, sidewalks CLASSIFICATION OF CONCRETE ACCORDING TO PURPOSE Lightweight Concrete - is made from lightweight coarse aggregates, such as shale, clay, or slate, and it has a particularly low density—thus the name. Lightweight concrete uses more water and more porous aggregates than regular concrete. Best For : Partition and panel walls in frame structures and wall insulation CLASSIFICATION OF CONCRETE ACCORDING TO PURPOSE Stamped Concrete - is concrete that has been imprinted, or that is patterned, textured, or embossed to resemble brick, slate, flagstone, stone, tile, wood, or various other patterns and textures. Best For : Patios, driveways, pathways, outdoor shopping malls, and pool decks CLASSIFICATION OF CONCRETE ACCORDING TO PURPOSE Pervious Concrete - is comprised of Portland or blended cement, water, and uniformly sized aggregate, and open spaces. Noticeably absent is sand. Pervious concrete allows water to pass through it to the sublease drainage area beneath, which is why it’s used in stormwater management systems. Best For : Stormwater management in pavements, driveways, parking lots, greenhouses, and low-traffic roads CLASSIFICATION OF CONCRETE ACCORDING TO PURPOSE Air Entrained Concrete - contains billions of microscopic air cells per cubic foot. These air pockets relieve internal pressure on the concrete by providing tiny chambers for water to expand into when it freezes. Air is incorporated into concrete by the use of an air-entraining admixture (also called an air- entraining agent) that is added to the fresh concrete Best For : Buildings, bridges, and highways CLASSIFICATION OF CONCRETE ACCORDING TO PURPOSE Asphalt Concrete - one of the most common types of pavement surface materials used in the world. It is a porous material made at a very high temperature of about 180°C that consists of mixture of asphalt binder (bitumen), aggregate particles, and air voids. Best For : Roads, parking lots, driveways, airports CLASSIFICATION OF CONCRETE ACCORDING TO PURPOSE Glass Concrete - Glass concrete uses waste glass, ground down to a powder as aggregate (in combination with or in place of sand and gravel) to create colorful terrazzo or granite and marble-like finishes. This process gives the concrete a sparkling iridescence. It is often used as a decorative finish. Best For : Interior flooring, counter-tops, fireplace surrounds, furniture  CONSTITUENTS OF CONCRETE 75% 15% 10% AGGREGATES CEMENT WATER Fine and Coarse Aggregates Finely milled mineral The component that initiates such as sand and Gravel powder, usually grey in the Hydration of Cement and colour that serves as an Aggregates. adhesive to bind sand, gravel, and hard rock in concrete. CONSTITUENTS OF CONCRETE AGGREGATES In concrete the major constituent in terms of volume is Aggregate. In essence concrete is like an artificial rock, consisting of aggregate materials bound together by hydrated cement. Aggregate is very important for many concrete properties, including; workability; shrinkage; thermal expansion; compressive and tensile strength. Aggregate is conventionally subdivided into two sizes, coarse and fine. CONSTITUENTS OF CONCRETE CEMENT Cement when mixed with water will form a paste that hardens into a strong rigid material. It is this paste that fills the voids between aggregate particles and binds them all together to form concrete. This hardening process (which occurs by a chemical reaction with water) is known as hydration. CONSTITUENTS OF CONCRETE WATER Water is needed in concrete for two reasons, firstly to hydrate the cement and secondly to provide mobility when the concrete is in its fluid state (workability). Generally, the amount of water needed for mobility purposes is greater than that required for hydration only. The water used should be clean, i.e. of drinking water quality. CONSTITUENTS OF CONCRETE CONSTITUENTS OF CONCRETE OTHER CONSTITUENTS OF CONCRETE ADMIXTURES Admixtures are materials, mainly liquids, that are added, to the concrete at the batching stage to modify the properties of the plastic or hardened concrete. There are a number of different types of admixtures, i.e., water reducing, plasticising, air entrainment, retarders, accelerators, shrinkage compensation, gas generation, water-proofing. TYPES OF ADMIXTURES ACCELERATING ADMIXTURES This type of admixture expedites the setting time of concrete for faster strength development. They increase the hydration rate of hydraulic cement when added to mortar or grout. They are utilised in situations where faster setting times are required, such as in cold weather conditions or for rapid construction schedules. TYPES OF ADMIXTURES RETARDING ADMIXTURES Retarders work oppositely to accelerators. They slow down the setting time of concrete. By slowing the initial setting time, the concrete mixture can stay in its fresh mix state longer before it gets to its hardened form. These are helpful when the concrete needs to travel long distances in special mixers or when it is hot outside. TYPES OF ADMIXTURES WATER-REDUCING ADMIXTURES These are the types of admixtures that enable the reduction of water content in the concrete mix without compromising its workability. They enhance the flowability of concrete, allowing for easier placement and better compaction. TYPES OF ADMIXTURES AIR-ENTRAINING ADMIXTURES These admixtures introduce microscopic air bubbles into the concrete mixture during mixing.These bubbles enhance the concrete’s durability by improving its resistance to freeze-thaw cycles, reducing bleeding, and improving workability. TYPES OF ADMIXTURES SUPER PLASTICIZING ADMIXTURES Superplasticisers are advanced water- reducing agents that greatly enhance the workability of concrete without increasing water content. They significantly improve the flow characteristics of concrete, allowing for easier placement in congested reinforcement areas.  BENEFITS OF ADMIXTURES 01 02 03 ENHANCED INCREASED OPTIMISED WORKABILITY STRENGTH AND SETTING TIME DURABILITY 04 05 IMPROVED REDUCTION IN PERFORMANCE IN WATER CONTENT CHALLENGING ENVIRONMENTS  CEMENT A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel (aggregate) together. CEMENT Mortar Cement when mixed only with fine aggregates and water produces mortar commonly used for Layering, Filler and for Plastering of Concrete Hollow Blocks. CEMENT Concrete Concrete on the other hand is produced when cement is mixed with fine aggregates, and coarse aggregates. CEMENT The selection of a particular type of cement to be used for manufacturing of concrete, depends upon the following factors : The required strength of the concrete structure. The type of structure. The conditions under which the construction of structure is to take place. HISTORY OF CEMENT ANCIENT HISTORY The first fired clay bricks were developed in the so- called Fertile Crescent, where it was discovered that lime could be produced from burnt limestone to prepare mortar. Around 800BC, the Phoenicians used the knowledge that a mixture of burnt lime and volcanic ash, today called 'pozzolana', could be used to produce hydraulic lime, that was not only stronger than anything previously used, but also hardened under water. HISTORY OF CEMENT Famous Historical Buildings: The Colosseum The Colosseum is an elliptical amphitheatre in the centre of the city of Rome, Italy, just east of the Roman Forum. It is the largest ancient amphitheatre ever built, and is still the largest standing amphitheatre in the world, despite its age. HISTORY OF CEMENT Famous Historical Buildings: The Pantheon, in Rome The Pantheon is one of the best-preserved monuments of ancient Rome. The structure, completed around 126-128 A.D. The Pantheon is situated on the site of an earlier structure of the same name, built around 25 B.C. by statesman Marcus Agrippa, and is thought to have been designed as a temple for Roman gods. HISTORY OF CEMENT Famous Historical Buildings: The Hagia Sophia in Istanbul Hagia Sophia, officially the Hagia Sophia Grand Mosque, is a mosque and former church serving as a major cultural and historical site in Constantinople, Turkey. The last of three church buildings to be successively erected on the site by the Eastern Roman Empire, it was completed in AD 537 HISTORY OF CEMENT The Birth of Portland Cement: The precursor to modern-day cement was created in 1824 by Joseph Aspdin, a British bricklayer and builder, who experimented with heating limestone and clay until the mixture calcined, grinding it and then mixing it with water. Aspdin named this Portland Cement, after the famously strong building stone from the Isle of Portland in Dorset, UK MANUFACTURING OF PORTLAND CEMENT The following raw materials are basically required for manufacturing of cement: Calcareous Materials – The materials which contain calcium or lime as their major constituent are known as calcareous materials. The various calcareous materials used in the manufacture of cement are lime stone, marl, chalk, shells, etc. These materials provide the required proportion of lime to the cement. Argillaceous Materials - The argillaceous materials contain alumina as their major constituent. The various argillaceous materials used in the manufacture of cement are shale, clay, laterite, etc. These materials provide the required proportion of silica, alumina, oxide of iron, etc. to the cement. MANUFACTURING OF PORTLAND CEMENT MANUFACTURING OF PORTLAND CEMENT PROCESS : 1. The process begins with the acquisition of raw materials such as limestone, clay, and sand. MANUFACTURING OF PORTLAND CEMENT PROCESS : 2. Limestones are then reduced by grinders to an approximately 5-in. size in the primary crusher and further reduced to 3⁄ 4 in. the secondary crusher MANUFACTURING OF PORTLAND CEMENT PROCESS : 3. All of the raw materials are then stored in the bins and proportioned prior to delivery to the grinding mill. MANUFACTURING OF PORTLAND CEMENT PROCESS : 4. They are then fed in rotating kilns, burning them at a temperature of about 1500C at which the material sinters and fuses to form nodular shaped clinker. MANUFACTURING OF PORTLAND CEMENT MANUFACTURING OF PORTLAND CEMENT There are two types of Processes in Portlant Cement Manufacturing : Wet Process Dry Process MANUFACTURING OF PORTLAND CEMENT WET PROCESS In this process, the limestone is crushed to smaller fragments and then it is taken to a ball or tube mill where clay or shale is mixed with it and ground to a fine consistency of slurry with the addition of water. The wet process results in a slurry which is mixed and pumped to storage basins. MANUFACTURING OF PORTLAND CEMENT MANUFACTURING OF PORTLAND CEMENT DRY PROCESS The raw materials are dried and crushed into a very fine powder. The dry powder is called raw meal. The dry powder is further blended and corrected for its right composition and mixed by using compressed air. The dry process produces a fine ground powder which is stored in bins. MANUFACTURING OF PORTLAND CEMENT CHEMICAL INGREDIENT OF CEMENT CHEMICAL INGREDIENTS OF CEMENT FUNCTIONS OF EACH CHEMICAL INGREDIENT Lime ○ Lime is the major ingredient of cement. It makes the cement sound and also provides strength to the cement. CHEMICAL INGREDIENTS OF CEMENT FUNCTIONS OF EACH CHEMICAL INGREDIENT Silica ○ Silica provides strength to the cement. Silica in excess causes the cement to set slowly. CHEMICAL INGREDIENTS OF CEMENT FUNCTIONS OF EACH CHEMICAL INGREDIENT Alumina ○ Alumina lowers the clinkering temperature and It provides quick setting property to the cement. CHEMICAL INGREDIENTS OF CEMENT FUNCTIONS OF EACH CHEMICAL INGREDIENT Iron Oxide ○ Iron oxide provides colour, hardness and strength to the cement. It helps the fusion of material at lower temperature during the manufacturing of cement. PROPERTIES OF CEMENT CHEMICAL PROPERTIES OF CEMENT CHEMICAL PROPERTIES OF CEMENT PROPERTIES OF EACH CHEMICAL COMPOUND CHEMICAL PROPERTIES OF CEMENT PROPERTIES OF EACH CHEMICAL COMPOUND CHEMICAL PROPERTIES OF CEMENT PROPERTIES OF EACH CHEMICAL COMPOUND CHEMICAL PROPERITES OF CEMENT PROPERTIES OF EACH CHEMICAL COMPOUND PHYSICAL PROPERTIES OF CEMENT 01 02 03 FINENESS SOUNDNESS CONSISTENCY 04 05 INITIAL AND FINAL SPECIFIC GRAVITY SETTING TIME PHYSICAL PROPERTIES OF CEMENT PHYSICAL PROPERTIES OF CEMENT PHYSICAL PROPERTIES OF CEMENT PHYSICAL PROPERTIES OF CEMENT PHYSICAL PROPERTIES OF CEMENT