The Effect of Water Cement Ration upon the Compressive - Assignment Example

Name of student: Course Title: Engineering Topic: The effect of water cement Ration upon the Compressive Strength of Concrete The effect of water cement Ration upon the Compressive Water is a natural chemical substance with the chemical formula H2O. The molecules of water are attached by covalent bonds. Water exists on Earth in different states; under ambient conditions it is a liquid, when near hydrophilic surfaces it exists as liquid crystals, it also exists as ice and vapor. Water is important for all forms of life and it covers about 70% of the Earth even in the deserts as well as the clouds. For as humans, we cannot do without water because we drink, wash, play and cook using water. Only about 2% of the water on Earth is fresh as about 98% is in ice and ground water. On Earth water usually moves continuously through a hydrological cycle i.e. evaporation, transpiration, condensation, precipitation and runoff. As water is important to all life forms it should be safe for drinking. For this reason, access to safe water has improved overtime in almost every part of the world but there are still short comings on the same. Recent reports found out that there will be a higher demand of water compared to the supply especially in developing nations. This is because water plays a vital role in the world economy at large, as it is used as a solvent for a wide range of chemical substances, industrial cooling and even transportation. It is amazing that the amount of water on Earth does not change as it is the same since the ancient days. The same water cannot also be seen as pure as it dissolves so many substances and can only be made pure in the laboratory. Properties of water Water is unique as it is the only natural substance found in all three physical states i.e. solid, liquid and gas at various temperatures on Earth. The following are the properties of water; It freezes at 15 °C and boils at 100 °C. Air pressure affects the boiling point as they are directly proportional. For example, at sea level water boils at 100 °C while at 5000ft it boils at 94.9 °C. Water has a high specific heat index as it absorbs a lot of heat before it begins getting hot. It absorbs/releases more heat for each degree of temperature increase/decrease. This enables it to be used widely for cooling and transferring heat in chemical and thermal processes. Pure water has a neutral ph of 7 and does not conduct electricity unless it has dissolved substances. The molecule is also highly cohesive compared to other non-metallic liquids. It has a very high surface tension as it tends to form clumps in drops rather than spread out. This high surface tension is responsible for the capillary action allowing water to move through the roots and blood vessels in plants and humans respectively. Water molecules are polar; this because as a whole molecule, one end (hydrogen end) tends to have a positive charge while the other (oxygen end) has a negative charge. This difference causes attraction which is responsible for the cohesion. Water has a relatively high density allowing sound to move through it for long distances. The density differs for it s different phases i.e. Liquid water is denser than solid water. This is essential for the survival of aquatic ecosystems and ultimately life on Earth. Water as solvent Water is generally important as a solvent for human and other life form activities. It is considered a universal solvent as it has the ability to dissolve other substances. Until date, there is no known substance that has not been identified in solution in the earth’s water. Water being a solvent is very vital for the existence of life as water transfers nutrients in animals and plants. When water falls as rain, it dissolves atmospheric gases and on reaching the earth, it affects the quality of the rivers, lakes and the whole land in general. Water as solvent has biological importance arising for its polarity. The biological importance is seen as many biochemical reactions occur only within aqueous solutions and also the transportation of biological molecules requires water. Greater quantities of different substances dissolve in water. The polarity of water enables it to dissolve both ionic (acids, alcohols, salts) and non ionic polar substances. Ionic bonds are broken with extreme ease while in water because of the competitive attraction of its molecules for other ions for example, salt ions that are usually strongly attached can be easily separated in water as they become hydrated. The hydration is also facilitated by the relatively small size of the water molecules allowing many of its molecules to surround one molecule of solute. The non polar substances usually stay together in water because it is energetically favorable for the molecules of water to maintain hydrogen bonds to each other than engage in Van Der Waal forces of interaction with the non-polar. The water /cementing ratio is the ratio of mixture of water to cement concrete. The concrete uses water/ cementing material of about ratio 0.45.for every 1kg cement in the mixture use 0.45kg water. The ratio must be lower for severe exposure and higher for molding exposure. The exposure versus water/cementing ratio will require a minimum of 28 days compressive strength. There are three samples of blended and proportioned numerous ways to make concrete and they include: the cement, aggregate and water. In the concrete mixture the amount of water used and the amount of cement used is known as the water cement ratio. The two combines the ingredients for binding. The water to cement ratio do determines the strength and durability concrete cured. For every ratio of 0.5 means that every 100 Ibs of cement concrete 50 Ibs will be added to it. Ordinary concrete of ratio 0.6 to 0.7 will be considered to be normal. The lower ratio of 0.5 will generally has a higher quality concrete desire. Conclusion Concrete is usually used in farm building project. Follow the guidance to apply for the regulations and through this it will lead to concrete structure with a strength, durability and integrity. References Smith, Hashimi.Foundations of materials science and Engineering: Fourth Edition, McGraaw-Hill Companied Inc.2006 ASTM C 39/C 39M- 01 standard Test Method for Static Modulus of Cylindrical Concrete Specimens M.Matlock, B.Howerton and D.Arwood, chemical precipitation of heavy metals from acids mine drainage, Water Research, Volume 36, Issue 19, November 2002,Page 4757 -4764 Read More