Ordinary Portland cement (C 53 grade) conforming to the requirements of IS 12269 (ASTM C 150-85A) was used in the study. Natural river sand was used as fine aggregate and crushed angular granite stone was used as coarse aggregate. Coarse aggregate with combined grading of 50% passing through 20mm sieve and retained on 12.5mm and 50% passing through 12.5mm and retained on 4.75mm sieve conforming to IRC 44 was adopted.
The bulk specific gravities of the coarse aggregate and fine aggregate were 2.67 and 2.65 respectively and their absorption values were 0.3%and 1.5% respectively. Commercially available poly-carboxylic ether based super plasticizer (Glenium B233) was used as chemical admixture. The product has specific gravity of 1.09 and solid
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The resulting hard substance, called ‗clinker‘, is the ground with a small amount of gypsum into a powder to make ‗Ordinary Portland Cement‘, the most commonly used type of cement (often referred to as OPC).Portland cement is a basic ingredient of concrete, mortar and most non-specialty grout. The most common use for Portland cement is in the production of concrete. Concrete is a composite material consisting of aggregate (gravel and sand), cement, and water. As a construction material, concrete can be cast in almost any shape desired, and once hardened, can become structural (load bearing) cement. Portland cement may be grey or …show more content…
Gravels constitute the majority of coarse aggregate used in concrete with crushed stone making up most of the remainder. Angular aggregate increase the void content. Larger sizes of well-graded aggregate and improved grading decrease the void content. Absorption and surface moisture of aggregate are measured when selecting aggregate because the internal structure of aggregate is made up of solid material and voids that may r not contain water. The amount of water in the concrete mixture must be adjusted to include the moisture conditions of the
There are several types of porous pavements, namely porous asphalt, porous concrete, and numerous modular paver systems. Both a construction material and a design technique, systems may be used individually or enhanced through a combination of types. Porous asphalt consists of an open-graded coarse aggregate bonded together by asphalt cement. The mixture contains fewer fines than traditional asphalt and sufficient void space between aggregate particles allows water to drain through quickly. Porous concrete also consists of an open-graded coarse aggregate, formulated with Portland cement and water. Modular porous pavers are structural units, such as concrete blocks or reinforced plastic mats, with void areas that are filled with pervious materials, to achieve a load-bearing permeable surface. The pervious fill materials include sand, grass turf, and gravel.
they're not. Concrete is to cement as a cake is to flour. Concrete is a mixture
Besides the known inventions and renovations of the Roman Empire, one of the building materials that the Roman Empire produced was concrete. With its strength, inexpensiveness and its easiness to work, the Roman Empire left an everlasting impact. Concrete that is a mixture of aggregate, which is usually gravel, sand or small stones, binding agents, and water is used to construct buildings and infrastructure. The first one, aggregate, gives the product its mass while the second one, binding agents, is used to harden the product. In the early times of the history, limestone powder was usually used as a binding agent in the mixture. The Romans later used “pulvis puteolanus” (pozzolanic ash), which was a fine volcanic ash as a binding agent and it allowed Romans to have strong concrete that is also durable (Yegeul, n.d.). It was easy to use
Strength In terms of strength the effect the plasticizers have on the polymers is that the additive makes the polymer have a weak intermolecular force. As a result of this the polymers will be unstable an easier to handle. Due to this the polymer then can be remoulded and tougher and this will increase the polymers
Gypsum, an evaporite that accumulated when shallow inland seas got cut off from the oceans and evaporated out, is found in large quantities in Central and North Central parts of the state. Calcined gypsum, which has been heated in a kiln, is made into sheetrock and pllaster. Regular gypsum is used in Portland cement and as a fuel additive, amoung other things.
Cement hardens when it comes in contact with water. Hardening is not a drying process and can very well take place in water. Heat speeds up the setting and hardening of cement and cold slows it down and can even completely stop the processes. In order to crystallize or hydrate, cement requires a quantity of water equal to 25% of its weight. But in order for it to be laid and remain sufficiently workable, twice this amount is usually required. However, too much water can reduce the strength and durability of the concrete. The paste (i.e. the mixture of cement and water) acts both as a lubricant and an adhesive. Hardening does not start as soon as cement and water are mixed, but after a certain length of time known as the “initial set time” during which the concrete can be mixed, transported, laid and vibrated. (All Public Works,
3) Super workable concretes have the ability to fill the heavily reinforced sections without internal or external vibration, without segregation and without developing large sized voids
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.
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,...
Concrete is a composite material used widely in the construction industry. Concrete is basically a mixture of cement, water, aggregates and admixture (sometimes). Cement is a fine gray powder that consists of oxidizes calcium, silicon and aluminum. The aggregate used is normally gravel, crushed stone or sand. Admixture is a solid or liquid substance that gives a certain characteristics of the concrete. The cement reacts with water chemically and binds the aggregates together through a process called hydration during hardening or curing of concrete. It means that water helps in the hardening of the concrete while the cement bind the aggregate and also react with water to form a solid mass.
For the case undertaken in this thesis work, the result we got according to the given options by the management of Lafarge Surma Cement Ltd. Indicates that, distributor storage with last mile delivery is the best choice of the distribution network. It is followed by retail storage with customer pick up and Manufacturer/Distributor storage with customer pickup. The selected network is tailored to match the characteristics of the product and the performance along with the needs of the customer. From the analysis, it is a suitable option for fast moving items for which some level of aggregation is beneficial. In this network, warehouse is much closer to the end customer and there is a requirement of high number of warehouses than other options.
Concrete "Pozzolana was used to make mortar and also, when mixed with lime and strengthening materials such as chips of rock and broken brick, concrete" (Kamm, n.d,). Concrete, of course, is a material that most people are familiar with. Today, concrete can
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.
Polymers popularly coined as “plastics” have proved their importance in different areas like FMCG, pharma, automobiles, etc. Plastics are versatile materials with unique properties like high strength to weight ratio, good aesthetics; good Processability, balanced engineering properties and optimum cost led its entry into medical
The substantial improvement of mechanical properties of polymer nanocomposites can be attributed to high rigidity and aspect ratio of nanoclay combined with good affinity through interfacial interaction between polymer matrix and dispersed nanoclay. It is well reported that polymer nanocomposites have excellent barrier properties against O2, CO2 and water vapor. This depends on the type of clay, i.e., compatibility between clay and polymer matrix, structure of nanocomposites and aspect ratio of clay platelets. Generally good gas barrier properties of polymer nanocomposite are archived by exfoliated clay minerals with large aspect ratio [91]. Also Rhim with his co-worker reported that water vapor transmission rate of agar/unmodified montmorillonite (Cloisite Na+) nanocomposite films is significantly lower than agar/organically modified montmorillonite (Cloisite 30B, 20A) nanocomposite [88, 89].