Concrete materials are still a dominant material for construction due to its advantages suchas workability, low cost and fire resistance as well as its low maintenance cost. It is formed from a hardened mixture of cement, fine aggregate, coarse aggregate, water and some admixture. Massive exploration of the natural resources for producing concrete affect to the environment condition and global warning. We have responsibility to reduce the effect of the application of concrete materials to environmental impact. The concrete should be used as efficient as possible.
Introduction The most important invention of the Romans was the invention of concrete, because it made a lot of other inventions possible. The Romans invented concrete by mixing pozzolana (which was a chocolate-colored volcanic material) and limestone. They then added strengthening materials like bricks and rocks. This mix was heated to a high enough temperature to make the substances fuse. The material would then be pulverized, with which you would get a powder.
The ancient Romans were great architects and engineers. For example, the Romans made concrete and brick and mortar. Concrete is a mixture of cement and gravel, When concret dried it was as strong as stone. Concrete is stronger than the cement We use today, because of the high use of volcanic ash. Brick and mortar is a building technique in which small fried bricks are held together by mortar .
The presence of MgO owed to limestone which had been used in makes lime. The presence of Fe is essentially owed to painted layer. Finally presence of Ti and Sr are sign of the organic rest. The EDX analysis of many places in the underneath colored layer showed the fine layer contains high percentage of CaO, SiO2 as the main elements. In addition to ZnO (zincite), indicating that the preparation layer is a mixture of lime, sand and zincite.
Shrinkage crack is caused by contraction of the total body due to loss of water content or moisture. Plastic shrinkage cracks are also formed by loss of water content in the concrete structure by evaporation. When the pace at which the water is evaporating exceeds the rate at which moisture is being supplied to it (via bleeding from the concrete), plastic shrinkage cracks are formed. It generally occurs in the plastic state (partially hardened state). Plastic shrinkage crack may not affect the strength of structure but will ruin the appearance of the structure and the crack to full depth may allow water to penetrate it.
Salt Free Systems Also known as descalers, salt free water systems can be exceptionally useful if your office or home is receiving hard water. This is a type of water that contains high amounts of magnesium and calcium. Hard water is dangerous for both the water pipes and the human body, thus making a saltless water softener a key item for reducing the hardness of the water. Iron Filters High concentrations of iron in the water are responsible for red stains on clothing and the onset of rust of water pipes. Our easy-to-install iron filters reduce the amount of ferric and ferrous iron from the water, making it safer and less corrosive.
3.5.2. CONCRETE MANUFACTURE This is a process that describes the making of fresh concrete cubes and testing for compressive strength. The test cubes had a nominal size of 150mm and maximum aggregate size of 20mm. Making test cubes from fresh concrete procedure was in accordance to BS 1881: Part 108: 1983 (cited in Ministry of works, 2000). EQUIPMENT USED • Moulds of cast iron or steel, with removable base plate were prepared.
The scarcity of fine aggregate for the production of mortar and concrete, as partial replacement of sand by Copper Slag have been identified. Several researchers have investigated the use of copper slag in the production of cement, mortar and concrete as raw materials for clinker, cement replacement, coarse and fine aggregates. This paper reports on some experimental investigations on the influence of partial replacement of sand by copper slag on the mechanical properties of concrete. M30 grade concrete was designed using copper slag, partially replacing the fine aggregate The fine aggregate was replaced by copper slag at various percentages ranging from 0%, 10%, 20%, 30%, 40%, 50%, 60%, 80% and 100%. The mechanical properties of concrete determined in the laboratory include compression strength, splitting tensile strength and flexural tensile strength.
Properties of Roller Compacted Concrete with Pozzolan as Cement Replacement Material Introduction: Roller compacted concrete (RCC) gets its name from the heavy vibratory steel drum and rubber-tired rollers used to compact it into its final form. RCC has similar strength properties and consists of the same basic ingredients as conventional concrete_ well graded aggregates, cementitious materials, and water_ but different mixture proportions. The largest difference between RCC mixtures and conventional concrete mixtures is that RCC has a higher percentage of fine aggregates, which allows for tight packing and consolidation . RCC may be considered for applications where no-slump concrete can be transported, placed, and compacted
Nowadays, when it comes to skin care, you will find quite a lot of products to choose from. Gone are the days when soaps are the only ones that are used to clean the body. Today, you have liquid soaps, body washes and gels too. For teens, using body washes have become convenient because they don 't leave any soapy residue on their skin that is hard to remove. Compared to soaps, body washes are less harsh on the skin so the chances of having dry skin are significantly reduced.