Study On Application Of Manufactured Sand In High Grade Concrete Of Mountainous Expressway

At present, with the natural river sand resources dry up increasingly and river sand mining leads to many disadvantages, such as damage to the environment, change in waterway shipping unsafe, destruction of cultivated land, etc., make people are looking at mechanism sand, so the mechanism of sand is widely applied to more and more, especially in the mountainous area highway, natural river sand and transport prices high, and or nearby area with a large number of mother rock, so can consider to sell mechanism of sand. Based on this background, this paper put forward the mechanism of sand in a mountainous area highway high grade concrete application research.Based on the mechanism of sand C50 concrete as the research block, follow these steps:Step 1: choose the right materials, including the mechanism of sand, gravel, cement,admixtures and water, to test these materials testing, the results of the selected corresponding materials meet the requirement of specifications, procedures, and can therefore be used to configure the C50 concrete.Step 2: the water/cement ratio calculated on the basis of the material properties, and then select the water-binder ratio 0.3, 0.32, 0.34, three groups as a benchmark test. After choosing fixed water and additive dosage rate, calculate the amount of other material, it is concluded that the corresponding mixture ratio.Step 3: according to the obtained mixture ratio, block production and experiment was carried out. Found three groups of block 28 d compressive strength, conform to the requirements of the ordinary concrete mix design procedures of; With the increase of water-binder ratio, concrete compressive strength is gradually diminishing, conform to the laws of Abrams. At the same time as the water gel is small, the concrete compressive strength was increased, but the increase rate is decreasing.Step 4: calculate the cost per cubic meter of concrete, the three groups of mixture are compared, and the cost to choose the second group for the final mixture ratio, its for cement:mechanism of sand, gravel, water: water = 495, 755:1042:158:10.4.Step 5: based on experimental results, verifies the practical engineering application and promotion.Mechanism is analyzed on the sand of economic benefit: the calculated per cubic meter of natural river sand C50 concrete cost, cost comparing with the selected mixture ratio, and found that use of sand mechanism can greatly reduce the cost; Sand because of its mechanism,to digest the stone discard, make its secondary use, thus reducing the land cost, project and soil field and prevent farmland, the role of environmental pollution. And the mechanism of sand, which is based on the project in the practical application of high grade concrete had significant economic and environmental benefits, such as in similar projects for the promotion,at the same time also made good benefit. Finally from the point of view of an environmental protection using the disadvantages of river sand profile reflects the use of the advantage of mechanism sand, sand at the same time concisely expounds the mechanism of high grade concrete at present in domestic promotion prospects.