Thank you, prof.….My name is …..I’m from …..I am very pleased to be here to join this forum.The topic of my presentation is properties of rapid construction materials for soil pavement of field airfield.As is shown in the picture, the main parts of my research are about soil pavement.
My presentation will include these four parts:
First, some background information about this research; second, the main work we have done; third, some conclusions we have got and the last: innovation and presentation of our published papers.
Why I choose this item? I think it can be illustrated from the following four parts.First, the existing quantity of airfields is still not sufficient and the airfields have many shortcomings especially in war time.Second, the complementary facilities, such as highway runways are far le than airfields, however, have more weakne.Third, a certain amount of field airfield is quite neceary considering some emergencies such as rescue and disaster relief.Forth, the field airfield can fill the void of airfield and they can be combined to be airfield network.
The meaning and aim of this research contains three parts.Fast, convenient and validity, fast means the field airfield must be constructed as fast as poible, convenient means the construction should need the minimum equipment, labor and materials considering the actual construction condition, validity means the constructed airfield is able to support the operation of given aircraft in specifically time.
Just like many other territories, the situation of the research is that the U.S.Army takes advanced line.The U.S.Army declares that they can reach to anywhere on the earth in 96 hours, the most important method for force projection is though aircraft, thus rapid construction of pavement is the key problem for rapid force transportation.
The main work we have done can be summarized as four parts, materials choosing, scheme making, mechanical properties research and water-stable properties research.
We choose two kinds of soils, which are got from Xi’an, Shanxi province and Jiuquan, Gansu province separately.The sand from Ba River was considerate to investigate the influence of sand to the properties of stabilized soil.The chosen three kinds of powders are cement, lime and new-type stabilizer developed by Chang’an University.The principles in considering the function of 4 kings of fibers are referring different length, type and mixing them.
On account of the time, I will make a brief description about the experiment scheme.In summary, three parts were proposed to distinguish the affecting factors in making experiment scheme.They are powder control, fiber control and other factors.Taking powder control for example, the dosage of cement is respectively 6%, 8% and 10% when the soil is stabilized only by cement, while the dosage of cement decrease to 3%, 5% and 7% when the lime is addicted to stabilized soil.The following two factors are stabilizer and sand.
Six kinds of experiments were performed to investigate the influence of above factors to the mechanical properties of stabilized soil.The aim of compaction test is to find the maximum dry density and optimum moisture content.The aim of compreion strength test is to determine the optimum dosage of cement, lime, powder stabilizer and fiber, meanwhile evaluating the performance of stabilized soil.The aim of splitting tension strength test is similar to compreion strength test, the left picture is sample stabilized by cement, while the right picture is the sample stabilized by fiber and cement.The direct sheer is another important parameter in geotechnical engineering.It influences the foundation bearing capacity and many other properties especially for soil base and base course.The left picture shows the course of making sample and the right picture shows the test proce.
The CBR test and rebound modulus test are referenced from highway test specification to evaluating the comprehensive capacities of each structure level of the pavement.For both the two tests, the left picture shows the course of making sample and the right picture shows the test proce.What should be noted is that the number of sample is at least 6, the last result is the average value of these date got from test after eliminating the bad results.
Four kinds of experiments were performed to investigate the influence of above factors to the water-stable properties of stabilized soil.The scouring test is not the stated experiment in current specification.It is performed by us through looking up large quantity of interrelated literature, and two different ways to carry out.The left picture shows the method of vibration table and the right picture shows the method of fatigue test instrument.Penetrant test refers to the experiment in relating concrete specification.The left picture shows the proce of saturation, the right picture shows the test proce.
Cantabria test and other tests are all original experiments; they are used in stabilized soil for first time, here I will not develop my narrative.
As regards the innovation, I think it throughout the whole research, including materials choosing, scheme making, mechanical and water-stable experiments.I think it can be drawled from the following keywords, such as soil choosing, sand, powders, fibers, and so on.Three main parts can be summarized.First, selecting two kinds of soils, three kinds of powders, several combinations; second, several kinds of fibers, different length and admixture; third, comprehensive experiments, test method and test instrument.
英语国际会议邀请函邀请信A Letter of Invitation5
