Rice Husk Ash ( Rha ) Essay

Step 1. The first thing you must do is gather corn husk, but not just any corn husk. You must gather the best and biggest husk out there. You must also gather a couple of sticks. You also need some string. It would be nice to have a scissors and a pocket knife as well.

Concrete floor is one of the most durable materials in the world. It can be made with waste products which help to reduce the consumption of valuable materials. It also can be made from fly ash, slag cement, and silica fume, all waste byproducts from steel mills, power plants and other manufacturing facilities.

To provide the client with the needed information regarding the material used on site, several tests were ran to determine if the roadbed material meets all of the requirements as stated in the Wisconsin Department of Transportation (WisDOT) 2016 Standard Specifications, Part 3, Section 301 and 305. The material has been identified as a ¾” dense graded crushed stone base aggregate. The sampling, aggregate properties, specific gravity, and sieve analysis were completed according to American Society for Testing and Materials (ASTM) and American Association of State Highway and Transportation Officials (AASHTO) standards.

When reading of the concrete that the ancient Romans used, and learning of their unique mixture of volcanic ash and slaked lime (“pozzolana”) I find it most interesting that this concrete still proves to be standing in some places today! It is said to be less sturdy than what we use here in America (Andrews, 2012) but no doubt it gave modern civilization the ingenuity to create what we use today.

The visit influences our practical as we gain an understanding of how in the engineering industry selection of materials is determined using indicators such as Young’s Modulus. Young’s Modulus is a measure of stiffness that is independent of the particular sample of a substance. This indicator is very vital as it determines the material’s strength, toughness

Introduction : To determine the strength, maximum load can be applied and workability of concrete mixture.

Not using the Mersey grit and using other aggregates with less potential for chloride would have been a better option. Also protection to the column facing the road should have been put in place, a physical barrier which could be replaced easily if it became damaged (a cheap barrier which would be cheaper than repair/maintenance of the column). The cement content when building structures exposed to harsh conditions form freeze-thaw, and de-icing salts should be “335 kg/m3”, also the water-cement ratio should be between “0.25 to 0.40 to maximize chemical resistance” (Beatrix Kerkhoff). The correct concrete in accordance with the EN 206-1 should have been chosen for the columns, the class which should have been chosen is XD3 which is for “Cyclic wet and dry” and recommended for “parts of bridges” and also for structures exposed to chlorides. Choosing the correct concrete cover is also important, the thicker the cover the more time it will take for contaminates to reach the steel.

Concrete has been used to build roads in America; although this is an expensive alternative to asphalt, it holds more advantages than normal asphalt. Concrete is more durable than normal asphalt and is capable of giving drivers better gas mileage. Concrete roads have also been proven to be more skid-resistant with the addition to grooves to the concrete. It can also help drivers save more gas money since it’s been proven to be fuel efficient. With the advances of modern science, scientists and concrete manufacturers have created some ways of creating concrete in a cheaper way so it can be used more often in creating

The Romans subsequently use finely ground volcanic lava in place of clay, deriving it mainly from the region of Pozzuoli. Their cement, known for this reason as pozzolanic, is the strongest mortar in history until the development of Portland cement. When small fragments of volcanic rubble are included, the result is concrete - making possible the great arches and aqueducts of Roman architecture, and playing its part in Roman roads.

Only 10% to 30% of the particles by mass are larger than 45 μm. The surface area is typically 300 to 500 m2/kg, although some fly ashes can have surface areas as low as 200 m2/kg and as high as 700 m2/kg. Fly ash is primarily silicate glass containing silica, alumina, iron, and calcium. Minor constituents are magnesium, sulfur, sodium, potassium, and carbon. Crystalline compounds are present in small amounts. The relative density (specific gravity) of fly ash generally ranges between 1.9 and 2.8 and the color is generally gray or tan. ASTM C 618 (AASHTO M 295) Class F and Class C fly ashes are commonly used as pozzolanic admixtures for general purpose concrete (Fig. 3-4). Class F materials are generally low-calcium (less than 10% CaO) fly ashes with carbon contents usually less

In the following decades lime and cement injections were the most widely used methods for stabilization of clay. However, hydration starts while water and cement are mixed But when water reaches cement, hydration happens and hydrated calcium silicates (CSH), aluminates (CHA) and lime (Ca(OH)2) would be generated which would and cause a rise in pore water pH. In 1971, [5] found the reactivity of clay minerals with acids and alkalines and afterward the usability of other chemicals other than lime and cement was investigated. Also, for reducing the stabilization costs, replacing cement with low cost waste materials has been studied. Moreover, the effect of portland cement manufacturing on amount of greenhouse released in the atmosphere and consequently, global warming has been another reason for finding a

Equally important, gradation of aggregate materials is carried out in order to achieve sufficient strength. The materials passing the No. 200 sieve is within acceptable limits to eliminate the effects of frost such as premature pavement failure (Mukabi & Ngaya 153). The strength and durability of the Subbase and base course materials are also enhanced through stabilization. This is achieved by applying either Asphalt or Portland cement to stabilize the subbase and base courses. Excessive compressive strength should be avoided as it may cause reflective pavement

Combination type SCC: This mix is obtained by adding a low amount of stabilizer or the powder type SCC to neutralize the moisture fluctuations. The target water-to-cement ratio is 0.4. Because of the increased amount of water in this mix, a lower amount of HRWR is used than in the powder-type SCC mix. Compared to powder-type mix, the combined mix design shall have a larger coarse aggregate content and a reduced amount of fine

The testing is done in a laboratory off-site. The only work done on-site is to make a concrete cylinder for the compression test. The strength is measured in Megapascals (MPa) and is commonly specified as a characteristic strength of concrete measured at 28 days after mixing. The compressive strength is a measure of the concrete’s ability to resist loads which tend to crush it.

Strength of concrete is dependent on a number of factors; one of the most important factors is the cement water ratio. The lower the ratio is, the higher the final strength of the concrete would be. Typical values for this ratio