Dry type production procedure The new technologies not only use CRM powder but also open grade additives such as PE powder. This paper will delineate PMA related technologies. 1) Open grade additives used in the new technology The mixture ratio of CRM, Polyethyene and other additives in our new technology is 40 -50 %, 30-50 %, 10-20 %. The main additives are CRM and PE. (1) Effects when using only LDPE to make it open graded First, the effect of open-gradation when PE is added to asphalt open grade solutions, SBS, SBR, LDPE, and LLDP. As thermoplastic resin, they are called polymer, elastomer, or plastomer and there is LDPE(Low Den sity Polyethylene), LLDPE(Linear Low Density Polyethlene) and EVA(EthyleneVynil Accetate) types. In the new technology, out of the polyethylene, we use LDPE, which have been researched domestically as an asphalt open grade additive and can be produced domestically. The chemical composition of this material is as follows: Material Volatility Viscosity Color Tensile Strength(Kg/§²) Type Softening Point LDPE 0.62 480 White 233 Powder 120¡­150¡É Results from the artificial aging test, chromatic analysis, that created a mixture by adding 3-7% of the additive to AP-3, and reports from simultaneous tests of the other mentioned open grade materials (June 1996 kangwon university high tech asphalt pavement research-Dr. Kim kwang-woo) confirm that LDPE is most resistant to the ageing process than the other materials mentioned. Also, open grade asphalt mixture made solely of the LDPE is on average about 40% stronger, and has 3.6 times higher elasticity than the asphalt mixture that didn't undergo open grade treatment. It was the highest among and much superior to all other road pavements. Also, the LLPE, as is shown in figure 7-1, has many long side chains but the LLDPE is made up of plain straight lines.   Figure 7-1 the structure of Nobophalt's open grade material. (microscopic picture and asphalt model) Therefore, compared with polymer, LDPE shows more strength than others. Also, the polyethylene's pores are dispersed widely along the asphalt's surface compared with SBS and SBR asphalt, and are known to have much more open gradation effect.   Figure 7-2 Test wheel tracking Figure 7-3 predicted A23's road plasticity after 8 years of usage (2) Open grade effect when adding CRM powder.   There are McDonald method and continuous bleeding method for the wet method of adding CRM. This method, most importantly, needs the equipment for open gradation process of asphalt such as the mixture tank for mixing CRM, maturation equipment, and it also requires precise supply method according to weight, consumption of thermal energy in proportion to the maturing time, quality maintenance such as accurate viscosity and temperature management, continuous movement of asphalt tank in the limited space of hot mixed asphalt factories, and much more. In short, the new technology is likely to make an epochal improvement in the following direction. The current dry-type method is known to inject 1mm-6.4mm rubber particles. Sweden's Skega AB and AB Vaegfoerbaetring company started producing the "Rubitol" product from the 1960's to 1978 ,when they were finally granted patent. It was called the "plus ride" technology. Before the mixing of asphalt, this method adds a portion of rubber powder to open grade aggregate and produces the CRM asphalt mixture. The particles of the rubber powder is thicker than McDonald's and is about 1.6mm-6.4mm long, and is 3%-6% heavier in total weight. The rubber particles are produced directly in hot mixed asphalt Plant Mixer in 25kg unit of plastic packages. This method views rubber particles as a part of the aggregate. This was from the Generic Drying Technology created by Mr. Takallow of Oregon University. The main purpose of this method was to expand the use of PlusRide construction method that was solely restricted to GapGrade for close grade and Gap grading. This method is also called the TAK method, and in New York City, asphalt mixture with 1%-3% mixture of rubber powder has been observed through construction tests. The chemical components of CRM are of the following The rubber tires are basically a compound of natural rubber(Malaysian natural rubber base) Synthetic Butil rubber, Carbon black, and other additives. Other than rubber, the fiber tissues and a wire are in close adhesion with the center of rubber in square form. The rubber powder mixture of recycled tires Chemical substance Passenger car/small sized vehicle (%) A medium-size passenger vehicle (%) Total rubber of a tire (%) Range(Min) Aceton Extract 17.2 11.4 15.1 5.8 Ash 4.8 5.1 5.0 0.28 Carbon Black 32.7 33.2 32 1.2 Rubber Hydrocarbon 42.9 50.2 47.9 7.3 The history of the use of CRM additives is of the following: The first time natural rubber was added to asphalt was in the 1840's. In the 1950's there was the first attempt to add tire rubber to asphalt but not until 1975 after a series of unsuccessful attempts did tire rubbers got added to road pavements. The procedure applied to our new technology before applying for patent is as follows CRM Mix ¡à Reason for adding CRM Asphalt with CRM added from the 1970's has proved to have the following advantages over the last 20-30 years.     ¢Ñ improvement of shortfall caused by the lack of adhesiveness between aggregate and additives ¢Ñ Prevention of high-temperature rutting (Plastic deformation) ¢Ñ Prevention of low-temperature crack ¢Ñ Increase of durability ¢Ñ Increase of economic efficiency of road (reduction of cost for maintenance due to increase of life cycle) ¢Ñ Recycling of material With regard to Dry Type, the Rubberized Asphalt Concrete Technology Center of the Ministry of Construction of Los Angeles, California has reported in detail of the CRM (i.e. RAC; Rubberized Asphalt Concrete). According to the latest news, the Blending process comprises of wet method, dry method, or refinery method. (Refer attachment) In additive, the report made by Dr. Kim Joo Won of Sungwon Technology Institute, in his report during the Korea Engineering Meeting, contains contents that are similar to the CRM Dry Type that was presented for patent as new technology . ¡ß Patent (Dry Type) 1. Uses a little lower ratio of rubber than Plus Ride Method and infinitesimal particles of rubber in proportion to those of aggregate. Smaller particles affects asphalt like filler and bigger ones forms elastic aggregate in the mixture. Ordinary dense aggregate is used and the distribution of rubber powder is adjusted according to the density of the aggregate. 2. Different from Method 1. Mixes rubber particles of No.80 size and the rubber powder acts as asphalt additive. The powder is believed to make asphalt open-graded in the process of mixing, storing and transporting to the construction scene. This method was tested in New York, Ilinoise, Florida, Kansas, Iiowa, Oregon, California, Ontario and Canada. The quantity is measured in weight and 1~3 % rubber power is used. The Compaction goes on till its temperature comes to 60 ° in Celsius to sustain its interaction with asphalt. Thus the PMA utilized in our new technology is currently in a stage of super powder, in which the PE and CRM are mixed together. It is utilized within 1-3% of the overall mixture. The quantity utilized is adjusted according to the use and grade of the road, and the change in climate. As for the use of CRM exclusively for CRM, the detailed process and quantity are substantially provided with. We have compared the results obtained when adding DAMA (Darin Asphalt Modified Additive) to not only asphalt but also to Dense Asphalt (#78) and SMA (Stone Metric Asphalt) The results are as follows: Test of result Test contents Korea Dry Material Test Institute (30. March 1999) VIATOP (Natural Fiber) #78general density #78+DAMA SMA+VIATOP SMA+DAMA Degree of Marshal 1,199 1,652(38%increase) 629 709(12%increase) Value of flow 33 38 30 44 Density 2.389 2.402 2.220 2.228 According to the above results, in case of #78 density and SMA, the degree of Marshal is increased by 12%, a 38% respectively. This clearly shows that in SMA, the Filler element and Binder are higher than in the case of #78, resulting in a mixture that is fluidity. The increase in degree of Marshal and value of flow shows the unique feature in which the PE and CRM react in an advantageous manner. Also, the DAMA that is applied to our technology could be viewed to substitute VIATOP (natural fiber) that is added to the domestic SMA. The method for putting DAMA to hot mix asphalt plant is as follows. With any separate need for extra equipment or additional heating, DAMA, which is packaged in low melt vinyl of 10kg/1bag, is put inside the present hot mixed asphalt factory's mixer. Around 1%to 3%of 1 ton is injected inside, and the mixing time when viewed under the present pug mill mixer type comes down to about one minute. Moreover, our company's DAMA is under exclusive import rights by England (DDM), where open grade asphalt was developed. Through this, it became possible for our company's new technology to be exported to Europe.