Study On The Technology Of Making Artificial Reserved Bricks By Using The Yellow River Sediment

The paper is based on Special Fund for scientific Research in the Public Interest by Ministry of Water Resource of the People's Republic of China (201501003),to be responsible for the "Study on the Technology of Making Artificial Reserved Bricks by Using the Yellow River Sediment" together with Yellow River Institute of Hydraulic Research, YRCC.The Yellow River sediment resource utilization is one of the important means to govern the Yellow River. Using the Yellow River sediment to make stone which is used for flood control can alleviate the pressure of the lower reaches of the Yellow River flood controlled meet the needs of economic and social development along the Yellow River, it is of great economic and social benefits. In the paper, After analysising the physical and chemical properties of the Yellow River sediment in Huayuankou and Mengzhou, through alkali excitation method and mixed proper amount of mineral power, red ash and black ash to make block material with a certain strength. At the same time, by means of microscopic test technologies such as XRD, IR and SEM to further explore the compressive strength enhancement mechanism of the Yellow River sediment composite gelled material which has been modified. Main research works are as follow.After alkali excitation modification on Huayuankou Yellow River sediment and Mengzhou Yellow River sediment by using different dosage of Ca(OH)2, the results show that after the modification of the Yellow River sediment,its compressive strength is improved obviously, with the increase of Ca(OH)2 dosage, the issue of the same age block compressive strength growth is becoming larger and larger within a certain range.XRD, TG-DTG and SEM test results indicate that after the use of Ca(OH)2 on the Yellow River sediment, the reaction products are mainly the amorphous gelling material and CaCO3.Modified the Yellow River sediment/mineral powder by Ca(OH)2 and NaOH respectively, then modified the Yellow River sediment/mineral powder by double mixing Ca(OH)2 and NaOH, study the compressive strength change trend of different curing conditions. The results show the compressive strength basic with the increase of Ca(OH)2 dosage increased after modifying the Yellow River sediment/mineral powder by using Ca(OH)2 and along with the age growth, the compressive strength of the modified the Yellow River sediment/mineral is also on the rise. When the Ca(OH)2 dosage is more than 5%, the block's compressive strength were greater than 13 MPa after 90 days, it is completely in line with the requirements of the compressive strength is greater than 10 MPa. The early compressive strength is growing rapidly after modifying the Yellow River sediment/mineral powder by using NaOH, but when the dosage of NaOH is more than 3%, the compressive strength showed a trend of deterioration. A good test results have been achieved after modifying the Yellow River sediment/mineral powder by double mixing Ca(OH)2 and NaOH, the early compressive strength is growing rapidly, and the late compressive strength degradation did not happen, whiskering is also improved. When the dosage of NaOH is 0.5%, the Ca(OH)2 dosage is 5% or 7.5%,the blocks reach 10 Mpa after 28days, And the compressive strength stability to keep the level of more than 10 MPa after 28 days.Using Ca(OH)2 and NaOH to excite the Yellow River sediment/black ash composite material, its properties indicates that the compressive strength of the property-modified Yellow River sediment/black ash composite material grow with the growth of Ca(OH)2,but its compressive strength is not obvious with the increase of age, even shows reverse trend. When exciting and modifying the properties of the Yellow River sediment/black ash composite material by NaOH,it is bad efflorescence and part of the surface of the test piece is off, and it appears some crackle.Using Ca(OH)2 and NaOH to excite the Yellow River sediment/red ash composite material, its properties indicates that the compressive strength of the Yellow River sediment/red ash composite material grows with the growth of the Ca(OH)2 when excited and modified by it. The early compressive strength of the composite material grows fast, but grows no more after 28 days'room temperature curing. Its reaction products in addition to the gel material and ettringite. To improve the compressive strength we add a small amount of NaOH and gypsum. The compressive strength is obviously improved. When the dosage of gypsum is 7.5%, NaOH dosage is 0.2%, Ca(OH)2 dosage is 5%,the compressive strength of the block reaches the peak, its compressive strength is 14.4 MPa after 90 days.