Showing papers on "Rubberized asphalt published in 2011"

Laboratory Investigation of Fatigue Characteristics of Rubberized Asphalt Mixtures Containing Warm Asphalt Additives at a Low Temperature

Abstract: The fatigue life of an asphalt pavement is directly related to various factors of a typical warm mix asphalt (WMA) mixture. Improving the understanding of the fatigue behavior of the rubberized WMA mixtures is helpful in recycling the scrap tires and saving energy. This study explores the utilization of the conventional fatigue analysis approach in investigating the cumulative dissipated energy, stiffness, and fatigue life of rubberized asphalt concrete mixtures containing WMA additives. The fatigue beams were made with one rubber type (−40 mesh ambient crumb rubber), two aggregate sources, two WMA additives (Asphamin and Sasobit), and tested at 5°C. The test results indicated that the addition of crumb rubber and WMA additive not only reduced the mixing and compaction temperatures of rubberized asphalt mixtures offset by crumb rubber but also slightly extended the long-term performance of pavement when compared with conventional asphalt mixtures.

Comparison of tire-pavement noise characteristics of rubberized and conventional asphalt concrete mixes

Abstract: This study compares tire/pavement noise characteristics of flexible pavement sections in California using the On-Board Sound Intensity (OBSI) method. Two experiments are presented in this work. The first one compares noise properties of pavement sections of different ages constructed with open-graded rubberized asphalt concrete (RAC-O) and gap-graded rubberized asphalt concrete (RAC-G) versus sections with conventional open-graded asphalt concrete (OGAC) and dense-graded asphalt concrete (DGAC). The second experiment compares the performance of trial sections that used different modified rubberized asphalt mixes as surface course. The results show that, compared with conventional asphalt concrete surface course of the same age, rubberized asphalt concrete surface courses have lower tire-pavement noise levels. The reduction comes mainly from better durability of rubberized asphalt concrete mixes. Additional information analyzed in this quieter pavement research study includes the effect of mix design variables and pavement surface distresses on tire-pavement noise characteristics of rubberized and conventional asphalt concrete mixes.

Warm-Mix Asphalt Study: Test Track Construction and First-Level Analysis of Phase 3a HVS and Laboratory Testing (Rubberized Asphalt, Mix Design #1)

Abstract: This is one of two reports describing the third phase of a warm-mix asphalt study that compares the performance of two rubberized asphalt control mixes with that of seven mixes produced with warm-mix technologies. The control mixes were produced and compacted at conventional hot-mix asphalt temperatures (>300 F [150°C]), while the warm-mixes were produced and compacted at temperatures between 36°F (20°C) and 60°F (35°C) lower than the controls. The mixes, test track, Heavy Vehicle Simulator (HVS) and laboratory testing are discussed. Key findings from the study include: Adequate compaction can be achieved on rubberized warm-mixes at lower temperatures. Optimal compaction temperatures will differ. Equal and potentially better rutting performance can be achieved provided that standard specified limits for hot-mix asphalt are met. Test results indicate that use of the warm-mix technologies did not significantly influence performance when compared to control specimens. However, the mixes produced with chemical surfactant technologies did appear to be influenced in part by the lower mix production and construction temperatures, which would have resulted in less oxidation of the binder and consequent lower stiffness of the mix. Rutting performance, fatigue performance and moisture sensitivity did not appear to be affected. The warm-mixes produced using water-foaming technologies appeared to have lower moisture resistance compared to the other warm-mixes. Smoke and odors are significantly reduced on warm-mixes compared to hot-mixes, while workability is considerably better on warm-mixes compared to hot-mixes. The HVS and laboratory testing completed in this phase have provided no results to suggest that warm-mix technologies should not be used in rubberized asphalt in California.

Moisture Susceptibility of Polymerized Stone Matrix Asphalt Mixtures using Warm Mix Asphalt Technologies using Moist Aggregates

Abstract: The present study is focused on evaluating the moisture susceptibility of polymerized stone matrix asphalt (SMA) mixtures using moist aggregates and three different warm mix asphalt (WMA) additives. Indirect tensile strength (ITS), tensile strength ratio (TSR), deformation, and toughness were performed to determine the moisture sensitivity of these mixtures. The experimental design included two aggregate moisture contents (0% and ∼0.5% by weight of dry mass of the aggregate), three sources of aggregates (A, B, and C) and three WMA additives (Asphamin, Sasobit, and Evotherm) along with control mixture, and four different types of binders (i.e., PG 64-22 + 10% crumb rubber (−40 mesh CR), PG 64-22 + 15% CR, PG 64-22 + 20% CR, and PG 76-22 with fibers) were used in this study. In total, 384 samples were utilized for the ITS testing in this study. Test results indicated that even though by using 2% hydrated lime as an anti-stripping agent, 32% of the mixtures failed to meet the TSR requirement of 85% as per SCDOT specifications. Mixtures with PG 76-22 + fibers showed improved wet ITS values compared to rubberized SMA mixtures as using moist aggregates. No significant differences in the wet deformation values were observed for mixtures using WMA additives using moist aggregates. Mixtures with 15% CR content showed improved resistance to the percent toughness loss under a warm water bath treatment. Test results indicated that recycled rubberized asphalt binder can be effectively used to improve resistance to moisture-induced damage of SMA mixtures as using WMA technology.

Rubberized asphalt pileup layers waterproofing materials with root barrier for the green roof and artificial foundation and its application method

Abstract: PURPOSE: A rubberized-asphalt laminated waterproofing material with a root barrier and an application method thereof are provided to implement safe and reliable greening on a building roof or artificial foundation CONSTITUTION: A rubberized-asphalt laminated waterproofing material comprises a first rubberized-asphalt coating waterproof layer, a stretchy asphalt felt layer, a second rubberized-asphalt coating waterproof layer, an asphalt felt sheet layer, and a root-proof sheet layer The first rubberized-asphalt coating waterproof layer is coupled to a base or primer layer of a concrete structure The stretchy asphalt felt layer is laminated on the top of the first rubberized-asphalt coating waterproof layer The second rubberized-asphalt coating waterproof layer is spread on the top of the stretchy asphalt felt layer The asphalt felt sheet layer is laminated on the top of the second rubberized-asphalt coating waterproof layer The root-proof sheet layer is laminated on the top of the asphalt felt sheet layer and blocks the roots of vegetation materials from penetrating the waterproof layers

Determination of Compacting Temperatures of Rubberized Asphalt Mixtures Containing Warm Mix Asphalt Additives

Abstract: To determine the compacting temperatures of rubberized asphalt (RA) mixtures containing warm mix asphalt (WMA) additives, a total of three RA binders were produced in laboratory using two kinds of WMA additives (Sasobit and CW), and one control binder without WMA additive. Brook rotational viscosity test of RA binders and Marshall compaction test of RA mixtures at various temperatures were conduced to study the viscosity-temperature properties of RA binders with WMA additives and analyze the volumetric properties of RA mixtures with different compacting temperatures, respectively. The results indicate that both Sasobit and CW can decline viscosity at testing temperatures and the compacting temperatures of RA mixes containing CW and Sasobit are 160°C and 154°C, respectively.

Determining on Construction Temperature of Warm Rubberized Asphalt Mixture

Abstract: Warm mix asphalt technology was used to improve rubberized asphalt mixture properties at construction temperature.Viscosity-temperature curve of warm rubberized asphalt binder and properties of mixture are test.Construction temperature affection on warm rubberized asphalt binder and properties of mixture was analyzed.Then construction temperature of warm rubberized asphalt mixture was decided.Results showed that construction temperature of warm rubberized asphalt mixture could be 30℃ lower than that of rubberized asphalt mixture.

Rubber asphalt emulsion flood protecting agent using acryl-silane primer and fast dried rubber asphalt emulsion and improving wetting adhesion and method for flood protection using the same

Abstract: PURPOSE: A rubber asphalt emulsion waterproofing material is provided to enable construction and the volatilization of coated surface and a solvent thereinside although the concrete surface is wet and to improve storage stability and properties. CONSTITUTION: A rubber asphalt emulsion waterproofing material comprises an acryl silane primer and a quick-dry rubber asphalt emulsion waterproofing material. The acryl silane primer includes 15~55 weight% of petroleum asphalt, 18~40 weight% of tetraethylorthosilicate or tetramethylorthosilicate or their mixture, and 25~55 weight% of acrylsilane copolymers. The quick-dry rubber asphalt emulsion waterproofing material includes 65~88 weight% of rubberized asphalt, 3~15 weight% of ethylalcohol, 0.1~2.0 weight% of silica sol, and 3~15 weight% of polypropylene glycol-polyethylene glycol.

Complex waterproof structure and constructing method of complex waterproof using membrane waterproof stuff and self-adhesive rubberized asphalt sheet

Abstract: PURPOSE: An asphalt sheet using membrane waterproof stuff and self-adhesive rubberized asphalt sheets and a complex waterproof construction method thereof are provided to improve waterproof performance and the service life of a waterproof layer CONSTITUTION: An asphalt sheet using membrane waterproof stuff and self-adhesive rubberized asphalt sheets comprises a concrete base(10), a primer(21), a waterproof coating material(22) for base adjustment, and a self-adhesive rubberized asphalt sheet(23) The primer is applied on the top of the concrete base The waterproof coating material for base adjustment is applied on the top of the primer in order to make concrete base flat The self-adhesive rubberized asphalt sheet is attached on the top of the waterproof coating material for the base adjustment

Performance evaluation of low environmental impact asphalt concretes using the mechanistic empirical design method based on laboratory fatigue and permanent deformation models

Abstract: The "sustainability" concept relates to the prolonging of human economic systems with as little detrimental impact on ecological systems as possible. Construction that exhibits good environmental stewardship and practices that conserve resources in a manner that allow growth and development to be sustained for the long-term without degrading the environment are indispensable in a developed society. Past, current and future advancements in asphalt as an environmentally sustainable paving material are especially important because the quantities of asphalt used annually in Europe as well as in the U.S. are large. The asphalt industry is still developing technological improvements that will reduce the environmental impact without affecting the final mechanical performance. Warm mix asphalt (WMA) is a type of asphalt mix requiring lower production temperatures compared to hot mix asphalt (HMA), while aiming to maintain the desired post construction properties of traditional HMA. Lowering the production temperature reduce the fuel usage and the production of emissions therefore and that improve conditions for workers and supports the sustainable development. Even the crumb-rubber modifier (CRM), with shredded automobile tires and used in the United States since the mid 1980s, has proven to be an environmentally friendly alternative to conventional asphalt pavement. Furthermore, the use of waste tires is not only relevant in an environmental aspect but also for the engineering properties of asphalt [Pennisi E., 1992]. This research project is aimed to demonstrate the dual value of these Asphalt Mixes in regards to the environmental and mechanical performance and to suggest a low environmental impact design procedure. In fact, the use of eco-friendly materials is the first phase towards an eco-compatible design but it cannot be the only step. The eco-compatible approach should be extended also to the design method and material characterization because only with these phases is it possible to exploit the maximum potential properties of the used materials. Appropriate asphalt concrete characterization is essential and vital for realistic performance prediction of asphalt concrete pavements. Volumetric (Mix design) and mechanical (Permanent deformation and Fatigue performance) properties are important factors to consider. Moreover, an advanced and efficient design method is necessary in order to correctly use the material. A design method such as a Mechanistic-Empirical approach, consisting of a structural model capable of predicting the state of stresses and strains within the pavement structure under the different traffic and environmental conditions, was the application of choice. In particular this study focus on the CalME and its Incremental-Recursive (I-R) procedure, based on damage models for fatigue and permanent shear strain related to the surface cracking and to the rutting respectively. It works in increments of time and, using the output from one increment, recursively, as input to the next increment, predicts the pavement conditions in terms of layer moduli, fatigue cracking, rutting and roughness. This software procedure was adopted in order to verify the mechanical properties of the study mixes and the reciprocal relationship between surface layer and pavement structure in terms of fatigue and permanent deformation with defined traffic and environmental conditions. The asphalt mixes studied were used in a pavement structure as surface layer of 60 mm thickness. The performance of the pavement was compared to the performance of the same pavement structure where different kinds of asphalt concrete were used as surface layer. In comparison to a conventional asphalt concrete, three eco-friendly materials, two warm mix asphalt and a rubberized asphalt concrete, were analyzed. The First Two Chapters summarize the necessary steps aimed to satisfy the sustainable pavement design procedure. In Chapter I the problem of asphalt pavement eco-compatible design was introduced. The low environmental impact materials such as the Warm Mix Asphalt and the Rubberized Asphalt Concrete were described in detail. In addition the value of a rational asphalt pavement design method was discussed. Chapter II underlines the importance of a deep laboratory characterization based on appropriate materials selection and performance evaluation. In Chapter III, CalME is introduced trough a specific explanation of the different equipped design approaches and specifically explaining the I-R procedure. In Chapter IV, the experimental program is presented with a explanation of test laboratory devices adopted. The Fatigue and Rutting performances of the study mixes are shown respectively in Chapter V and VI. Through these laboratory test data the CalME I-R models parameters for Master Curve, fatigue damage and permanent shear strain were evaluated. Lastly, in Chapter VII, the results of the asphalt pavement structures simulations with different surface layers were reported. For each pavement structure, the total surface cracking, the total rutting, the fatigue damage and the rutting depth in each bound layer were analyzed.

Waterproof sheet including rubberized asphalt self-adhesion type waterproof material, and waterproofing method threrby

Abstract: PURPOSE: A waterproof sheet including a rubberized asphalt self-adhesion type waterproof material is provided to ensure excellent waterproof function blocking moisture, low temperature softness, and excellent adhesion. CONSTITUTION: A waterproof sheet including a rubberized asphalt self-adhesion type waterproof material has a structure in which a rubberized asphalt self-adhesion type waterproof material and a release film are successively laminated on a high density polyethylene film. The rubberized asphalt self-adhesion type waterproof material includes: 30~70 weight% asphalt; 1~30 weight% styrene-based block copolymers; 0.5~20 weight% paraffin-based viscoelastic synthetic oil in which a flowage point is -60 °C, viscosity(25°C) is 200 cp, an ignition value is 250 °C or more; 0.5~20 weight% petroleum resin; and 5~20 weight% polybutene in which viscosity(100°C) is 230 cp, an ignition value is 190°C, and a flowage point is -10 °C.

The investigation of rubber modified bitumen as a binder for the production of asphalt mixture

Abstract: The use of waste tire rubbers as bitumen modifiers can contribute to alleviate pollution problems derived from discarding scrap tires. The influence of waste tire rubber powder on mechanical and rheological properties of rubberized bitumen binders were examined for samples prepared with pavement grade bitumen B50/70. The experimental data were compared with those for native bitumen B50/70 modified with amine by using the same preparation protocol as for rubberized binders. In order to examine the effect of waste rubber powder on mechanical properties of asphalt mixtures, rubberized asphalt mixtures AC 8surf were prepared according to wet and dry procedures. The mechanical and rheological properties of extracted bitumen from these asphalt mixtures were compared with the properties of extracted bitumen from asphalt mixture AC 8surf prepared without rubber powder. It was found that the addition of crumb tire rubber powder to bitumen increases, storage and loss modulus, rutting parameter and dynamic viscosity, at high in-service temperatures. From mechanical tests it was observed that presence of rubber powder in bitumen increases ring and ball temperature and decreases Fraass temperature. As a consequence, crumb tire rubber modified bitumen displays enhanced mechanical properties, which improves its resistance to both rutting and fatigue cracking.

Rubberized asphalt self-adhesive waterproofing sheet

Abstract: PURPOSE: A rubberized asphalt-based self-adhesive waterproof sheet is provided to avoid non-woven fabrics within a waterproof material due to excellent durability of a base film and to ensure excellent adhesive property. CONSTITUTION: A rubberized asphalt-based self-adhesive waterproof sheet has the structure where a rubberized asphalt-based self-adhesive waterproof material and a release sheet are laminated on a cross-laminated plastic film, wherein the rubberized asphalt-based self-adhesive waterproof material includes 10-30 wt% of polyisobutylene synthetic rubbers, 20-40 wt% of styrene isoprene styrene synthetic rubbers, 1-30 wt% of polybutene, and 20-50 wt% of asphalt.

Method of constructing asphalt using rubberized asphalt self-adhesion type waterproof sheet

Abstract: PURPOSE: A construction method of asphalt using rubber asphalt system self-adhesive type waterproof sheet is provided to simplify construction by using a non-fusing and heating bonding method. CONSTITUTION: A construction method of asphalt using rubber asphalt system self-adhesive type waterproof sheet is same like next. The foreign material of the excavated existing ascon layer joint vertical plane(A) is eliminated. The asphalt primer is spread on the joint vertical plane and cured. The rubber asphalt system self-adhesive type sheet is attached to the joint vertical plane. After the sheet is attached, a melting ascon layer is poured. The rubber asphalt system self-adhesive type sheet thickness is 2~4mm.

Rubberized asphalt self-adhesive waterproofing sheet and waterproofing method threrby

Abstract: PURPOSE: A rubberized asphalt self-adhesive waterproofing sheet is provided to adhere without using a primer on a concrete basal plane. CONSTITUTION: A rubberized asphalt self-adhesive waterproofing sheet(100) is made by cutting a cylindrical plastic film into 22.5~67.5 degree in order to be screw shape, and bonding the two cut film by facing each other using polyurethane adhesive. The rubberized asphalt and mold release sheet is piled. The rubber asphalt is made of 10~30 weight% polyisobutylene synthetic rubber, 20~40 weight% styrene isoprene styrene synthetic rubber, 20~50 weight% asphalt, 1~30 weight% polybutene.