Higher Indirect Tensile Strength Research Articles

Experimental Research on the effect of Structural glass fibre in the Tensile Strength Ratio and Retained Stability of VG40 Bituminous mix

Abstract The tensile characteristics of bituminous mix are a major concern for pavement engineers due to the cracking issues. The cracking infuses moisture into the pavement layers which affects the stability of the pavement. The measures to reduce the fatigue tensile cracks have to be taken in the design stage rather than the maintenance stage. The tensile properties and the stability are evaluated using the indirect tensile strength and retained stability tests. While fibers improve the tensile properties of pavement, the S-glass fiber possessing superior mechanical strength has been found to have less scope in past studies. Thus, the current study primarily focuses on examining how Structural Glass fiber reinforced in VG-40 bituminous concrete mix improves the tensile and moisture susceptibility characteristics. The Marshall technique of bituminous mix design was used to establish the ideal bitumen content for casting the bituminous concrete specimens. At the ideal bitumen content, the attributes of bituminous mixes were established. Tensile strength ratio (TSR), Indirect Tensile Strength (ITS), and Retained Stability of modified bituminous concrete mix were assessed. It is observed that the bituminous mix prepared by adding the S-Glass fibre of 8mm length by 3% weight of aggregates exhibited higher ITS, TSR, and Retained stability. The bituminous mix with glass fiber incorporated had higher retained stability (95.36%) than the conventional mix (91.17%). The results of the Indirect Tensile Strength Test revealed that the mix with glass fiber added had a higher Tensile Strength Ratio (92%) compared to the mix with conventional fiber (87%). A noteworthy outcome that creates opportunities for more study in this field is the rise of 5% TSR and 4.66% maintained the stability of the glass fiber-modified bituminous mix.

Design and performance assessment of sustainable road pothole patching materials using waste cooking oil, plastic, and reclaimed asphalt pavement

Pothole repairing is routine and substantial maintenance work for public work agencies to improve road conditions and traffic safety. This study developed sustainable and cost-effective pothole patching materials by circular uses of three recyclable materials, including reclaimed asphalt pavement (RAP), waste cooking oil (WCO), and plastic. The biobinder was synthesized via the polymerization of WCO with co-crosslinker Maleic Anhydride (MA). The low-density polyethylene (LDPE) plastic was used to modify a biobinder to enhance its elasticity. Results showed the RAP-biobinder mixtures and RAP-biobinder-plastic mixtures had higher indirect tensile strength and improved rutting resistance compared to the RAP-WCO mixtures. The designed patching mixtures exhibited superior mechanical performance compared with the commercial cold patch mixtures. Field pothole patching tests were also conducted to assess the workability and patching performance of the developed patching mixtures. The RAP-WCO mixture demonstrated sufficient workability and effective patching performance based on one-year monitoring.

Assessment of Traditional Asphalt Mixture Performance Using Natural Asphalt from Sulfur Springs

This research utilized natural asphalt (NA) deposits from sulfur springs in western Iraq. Laboratory tests were conducted to evaluate the performance of an asphalt mixture incorporating NA and verify its suitability for local pavement applications. To achieve this, a combination of two types of NA, namely soft SNA and hard HNA, was blended to create a binder known as Type HSNA. The resulting HSNA exhibited a penetration grade that adhered to Iraqi specifications. Various percentages of NA (20%, 40%, 60%, and 80%) were added to petroleum asphalt. The findings revealed enhanced physical properties of HSNA, which also satisfied the requirements outlined in the Iraqi specifications for asphalt cement. Consequently, HSNA can serve as an asphalt binder to produce asphalt mixtures for flexible paving construction. Notably, HSNA mixtures exhibited greater Marshall stability and stiffness index when compared to traditional mixtures. The results from indirect tensile strength (ITS) and tensile strength ratio (TSR) tests indicated that the 80NA mixture displayed the highest ITS values and a TSR of 81.36%, surpassing the TSR of the mixture incorporating petroleum asphalt by 0.57%.

Study on Application of Iron Tailings in Cement Stabilized Macadam

With the rapid development of ferrous metallurgy, the production of iron tailings as waste after beneficiation is increasing. Due to the shortage of natural stone in road construction, iron tailings can be used as an alternative material to natural stone in semi-rigid bases. In order to study the feasibility of application of cement stabilized iron tailings (CSIT) in semi-rigid base, unconfined compressive strength (UCS), indirect tensile strength (ITS) and cyclic freeze-thaw tests were carried out on cement stabilized iron tailings (CSIT). The gradation composition and cement content were selected as influencing factors. The results show that under the condition of the same cement content, the UCS and ITS of CSIT are proportional to the particle size in the mixture. In CSIT with the same gradation, the mechanical properties increase with the increase of cement content; CSM-40(B) has a higher UCS and CSM-40(C) has a higher ITS, the frost resistance coefficient of CSIT increases with the increase of cement content and the tendency of frost resistance coefficient decreases with the increase of cement content. The frost resistanceofCSM-40 (B) is better than that of CSM-40 (C) for the same cement content. Therefore, for the use of iron tailings in CSM, a suitable gradation composition and cement content should be selected.

Evaluation on long-term performance of emulsified asphalt cold recycled mixture incorporating fly ash by mechanistic and microscopic characterization

In this paper, the long-term performance of emulsified asphalt cold recycled mixture (CRME) incorporating fly ash was investigated. The dosages of fly ash included 0.75%, 1.5% and 3.0%, and the long-term service conditions of CRME were simulated by curing in an oven at 60 °C for different ages. Mechanical performance of CRME under different curing ages were obtained through indirect tensile strength (ITS), Marshall stability, low-temperature ITS and freeze-thaw ITS tests, and the microstructures were characterized by optical microscope, X-ray diffraction (XRD) and environmental scanning electron microscopy (ESEM) tests. The results show that, as the curing age increases, the ITS, flow value, and low-temperature indirect tensile strain of CRME with fly ash increase first and then decrease, while the Marshall stability and freeze–thaw ITS ratio (TSR) always show a gradual increase trend. By comparing the CRME with cement, the CRME with fly ash throughout the long-term curing process exhibits the higher ITS and low-temperature anti-cracking performance and the lower high-temperature stability and water stability. Optical microscope, XRD and ESEM analysis indicate that the dissolution of fly ash particles and the demulsification of asphalt emulsion particles occur simultaneously during the curing ages. After a certain curing age, a dense structure composed of asphalt binders, dissolved and undissolved fly ash particles is formed. Also, the fly ash replacing cement in CRME can effectively reduce the energy consumption and carbon emission.

Valorisation of lignin-rich industrial byproduct into half-warm mix reclaimed asphalt with enhanced performance

To promote a circular economy and sustainable development, the possibility of using a lignin-rich industrial byproduct as a partial substitute for asphalt emulsions in road pavements is analysed. A half-warm mix reclaimed asphalt (HWMRA)-type AC 16 surf S, manufactured with 100% reclaimed asphalt pavement, is selected. Substitution percentages of 0% (control mixture), 5%, 10%, 15%, and 20% are employed.The microstructure of the blend of the byproduct and asphalt emulsion is observed using scanning electron microscopy. The water resistance of the mixture is investigated using indirect tensile tests, as well as its volumetric properties. The stiffness, thermal susceptibility by indirect tensile tests, and resistance to permanent deformation by confined uniaxial compression tests and Hamburg wheel tracking tests are also studied.The optimum percentage of byproduct substitution is 5%, resulting in an enhanced HWMRA with a slightly better water resistance, higher resistance to permanent deformation at low and medium environmental temperatures, and higher indirect tensile strength and stiffness than those of the control mix.

Evaluation of measured and predicted resilient modulus of rubberized Stone Mastic Asphalt (SMA) modified with truck tire rubber powder

Rubberized asphalt is known for its elastic deformation recovery and good resilience in response to loads owing to the elastic characteristics of tire rubber powder. There are several methods for the prediction of the stiffness modulus of asphalt mixtures. However, there are limited studies on predicting the stiffness modulus incorporating both wet and dry rubberization methods based on the available methods of Asphalt Institute (AI) and IDOT (Illinois department of transportation). In this research, Stone Mastic Asphalt (SMA) mixtures were modified with truck tire rubber powder (TRP) with two different processes: SMA-WP (SMA mixtures modified in the wet process) and SMA-DP (SMA mixtures modified in the dry process). In both methods, 3%, 6%, and 9% of TRP were used for modification, and the performance of the control and modified mixtures was evaluated under indirect tensile strength (ITS) and indirect tensile stiffness modulus (ITSM) tests. Finally, the results of ITSM were compared to predicted resilient modulus based on the Asphalt Institute (AI) and Illinois Department of Transportation (IDOT). The experiments revealed that SMA-DP mixes have higher ITS than SMA-WP. At the same time, both methods showed a decrease in ITS as TRP content increases. Furthermore, the SMA-WP samples showed a lower phase angle than SMA-DP samples, indicating higher elasticity for the mixtures. In addition, SMA-WP showed lower horizontal deformation than SMA-DP, which helps reduce rutting on the surface layer. Finally, the prediction results showed that the IDOT method could not predict the Stiffness Modulus, while the AI method was more accurate and can be used for prediction.

Evaluation of durability against wetting and drying cycles of cement-natural rubber latex stabilised unpaved road under cyclic tensile loading

ABSTRACT Cement stabilised unpaved roads have been implemented worldwide in both developed and developing countries. In this research project, natural rubber latex (NRL) was used to improve the durability against wetting and drying (w-d) cycles of cement stabilised soil, under cyclic tensile loads. The influences of NRL replacement ratio on the indirect tensile strength (ITS), indirect tensile resilient modulus (IT Mr), and indirect tensile fatigue life (ITFL) prior to and after w-d cycles were studied. Cement-NRL stabilised soil was found to have superior resilient properties to minimise the plastic deformation and prevent sudden damage against the repetitive tensile stresses. The NRL replacement could improve the durability against w-d cycles of cement stabilised soil whereby the highest ITS, IT Mr, and ITFL were found at the optimum NRL replacement ratio of 20% for all number of w-d cycles tested. NRL was found to enhance the service life of cement stabilized soil as an unpaved material against fatigue cracking failure. The outcome of this research will promote the usage of NRL, which is available in plentiful supply in Thailand and other Southeast Asian and South American countries, as a sustainable additive in pavement applications.

The effect of different deicing solutions on the moisture susceptibility of asphalt mixture

The present research studies the effectiveness and efficiency of solutions such as sodium chloride, magnesium chloride and potassium acetate on asphalt pavement to reduce the damage caused by moisture on asphalt pavement in winter. To prevent the stripping problem in asphalt, Nano-Zycotherm with three quantities corresponding to 0.1%, 0.2% and 0.3% weight of bitumen is used in this study. Under the saturated condition with the above solutions, the indirect tensile test performs by applying a freeze–thaw cycle as a means to measure the amount of moisture susceptibility. The results indicate that the asphalt mix containing 0.3% Nano-Zycotherm has a higher indirect tensile strength and tensile strength ratio than asphalt mix containing 0.1% and 0.2% Nano-Zycotherm. Accordingly, Magnesium chloride solution is the most effective deicing material to improve the indirect tensile strength and durability of asphalt pavements when faced with moisture and ice.Article highlightsThe presence of Nano-Zycotherm in asphalt leads to its increased resistance against stripping.The use of Sodium chloride and potassium acetate deicing solutions causes some damages in asphalt.Considering different solutions, magnesium chloride has the best performance against asphalt stripping.

The effects of gilsonite and crumb rubber on moisture damage resistance of stone matrix asphalt mixtures

The current study was performed to investigate the influence of gilsonite on properties of binder and moisture resistance of SMA mixtures modified by Crumb Rubber (CR) additive. For this purpose, softening point, penetration, and Dynamic Shear Rheometer tests were implemented to investigate the performance of different binders. To evaluate the water sensitivity of modified mixtures, four different methods were performed, including Resilient Modulus Ratio (RMR), Fracture Energy Ratio (FER), Tensile Strength Ratio (TSR) and Texas boiling. To analyze the data, two-factor analysis of variance (ANOVA) was carried out. Based on the results, utilization of Gilsonite additive enhances the Resilient Modulus (Mr), Indirect Tensile Strength (ITS), and Fracture Energy (FE) of asphalt mixtures. The results also revealed that by utilization of CR, ITS and FE values increase. While, the MR values increase by addition of 10% CR, and by addition of higher percentages of CR (15 and 20%), the MR values decrease. Among different specimens fabricated, mixtures containing 30% Gilsonite and 20% CR have the highest ITS and FE values. Also, according to the results, 30% Gilsonite mixture modified by 20% CR has the highest TSR, and FER value, which indicates that the mentioned specimens have better resistance to water susceptibility.

Influence factors of strength and performance of foamed asphalt cold recycled mixture

This paper investigates the factors that influence the strength and moisture damage resistance of foamed asphalt cold recycled mixtures. The relevant factors include gradation, asphalt penetration, mixing temperature, particle size of virgin aggregates, and the curing time and moisture content. Indirect tensile strength (ITS) tests under dry and wet conditions were conducted to evaluate the mixture properties. The test results indicated that minute variation in foaming parameters (i.e. expansion ratio and half-life) for asphalt binders with different penetration grades, had no significant effect on the strength and performance of foamed asphalt cold recycled mixtures. The results also revealed that the mixture with medium-grained gradation exhibited higher ITS than mixtures with coarse- and fine-grained gradation. As the temperature of the added virgin aggregates increased, the ITS and moisture damage resistance of the mixture increased as well, but the difference was quite small. It was also observed that the mixture demonstrated better ITS and moisture damage resistance when using filler in material design. The relationships between curing time, moisture content, and strength of the mixture during curing were also investigated, and the variations of strength formation was summarised. The significance of the studied factors was finally analysed using a one-way analysis of variance based on the test results.

Predictive model of modified asphalt mixtures with nano hydrated lime to increase resistance to moisture and fatigue damages by the use of deicing agents

Deicing agents are used to dissolving the frost on road surfaces in winter and cold areas. Researchers have evaluated the impact of different deicing agents on the moisture susceptibility performance of asphalt mixtures, but they have not investigated the effect of these agents on fatigue failure and thermodynamic parameters of asphalt mixtures. Therefore, in this research, by investigating the effect of two new deicing agents of calcium magnesium acetate (CMA) and potassium acetate (PA) as well as sodium chloride (NaCl) traditional agent on moisture and fatigue performances of asphalt mixtures, predictive model of the tensile strength ratio (TSR) and the fatigue life ratio (NFR) using genetic programming (GP) based on the surface free energy (SFE) components and other properties of asphalt mixtures were presented. Nano hydrated lime (NHL) was applied as an asphalt binder modifier and an anti-stripping agent to improve the strength of asphalt mixtures. The results indicated that the saturated mixtures in CMA had the highest indirect tensile strength (ITS) and fatigue life in lower freeze-thaw cycles, while the NaCl-saturated samples had more ITS and fatigue life in higher cycles. The CMA-saturated samples had the greatest TSR and NFR. Using NHL in all saturated samples resulted in increasing TSR and NFR values. Results of SFE method showed that using NHL increased the polar, non-polar and basic components of asphalt binders and decreased their acidic components. Also, using NHL increased the total SFE amount of asphalt binder, enhancing the adhesion of aggregate and asphalt binder and cohesion in asphalt binder membrane, and as a result, improving the moisture resistance in asphalt mixtures. Using 1.5% NHL had the greatest effect on improving adhesion free energy (AFE), cohesion free energy (CFE) and detachment energy (DE). Among deicing solutions, CMA had the highest CFE, in general, and NaCl had the best DE values. PA-saturated samples had the greatest permeability of asphalt mixture (PAM) values. GP model had a high R2 96.4% and 98.3% for TSR and NFR, respectively. Using GP model to achieve the maximum TSR and NFR, the Pareto curve showed that 1.32% NHL was the optimum value for simultaneously increasing moisture resistance and fatigue life.

Moisture Susceptibility of Open-Graded Friction Course Mixes with EAF Steel Slag and Modified Binders

Abstract Open-graded friction course (OGFC) mixtures are sensitive to the moisture damage because of their high air void content and longer exposure to water. In the present study, moisture susceptibility characteristics of OGFC mixes in terms of tensile strength characteristics, aggregate-binder bond strength, and the raveling potential of OGFC mixtures were studied. The experimental design for this study included OGFC mixes with two different types of aggregates (natural aggregates as a main source and electric arc furnace (EAF) steel slag as a secondary source), two different types of modified binders (polymer-modified bituminous binder and crumb rubber–modified bituminous binder), and one cellulose fiber as an additive. OGFC mixes were designed with five different percentages (0, 25, 50, 75, and 100 %) of secondary aggregates as a partial replacement of main aggregates. OGFC mixes were then evaluated for moisture susceptibility through four different test methods, viz. the indirect tensile strength (ITS) or tensile strength ratio (TSR) method, wet abrasion loss (WAL) method, static immersion test method, and modified boiling test method. OGFC mixes with EAF steel slag showed higher ITS values under both dry and wet conditions compared with the control mixes with natural aggregates alone. Steel slag content, binder type, and freeze-thaw cycles had statistically significant effects on the ITS, TSR, and WAL values. Modified boiling test results showed a good correlation with the modified Lottman and WAL test results.

Investigating the mechanical properties of asphalt concrete containing waste polyethylene terephthalate

Reviewing the literature shows that limited work has been conducted on polyethylene terephthalate (PET)-modified asphaltic materials with inconsistent results, missing the investigation of some aspects such as the effect of PET particle size. This paper investigated the effects of waste PET content and particle-size distribution on some engineering properties of asphalt concrete. To this end, Marshall specimens of the mixtures containing different ground waste PET contents of 0%, 2%, 4%, 6%, 8%, and 10% (by the weight of asphalt binder) were subjected to Marshall, indirect tensile strength (ITS), moisture damage, and dynamic creep tests. Two different sizes of PET particles were used: one with particles in the range of 1.18–2.36 mm as coarse-graded PET, and the other with particles in the range of 0.297–0.595 mm, as fine-graded PET. ITS test was conducted on dry and conditioned specimens to evaluate moisture damage susceptibility. Dynamic creep tests were performed under the stress level of 300 kPa at 40°C. Results show that, for both coarse- and fine-graded PET particles, the highest Marshall quotient is achieved at 4% of PET content, after which it decreases with increasing the PET content. Furthermore, results indicate that, for both fine and coarse PET particles, the mixture containing 2% of PET content has the highest ITS and resistance against moisture damage. Based on dynamic creep test results, the resistance against permanent deformation decreases with increasing the PET content. Comparing the results for the mixtures containing coarse and fine PET particles shows that a better performance can be achieved using finer PET particles.

Impact of binder on properties of foamed bituminous mixtures

Foamed bitumen technology is gaining acceptance across the world as an approach towards sustainable road construction. This technology offers advantages in terms of reduced energy consumption, materials recycling and reduced bitumen requirement. The properties of foamed bitumen mixtures depend on various factors, including the properties of the constituent materials and production conditions. This paper concentrates on the influence of the properties of the binder on the foaming characteristics of bitumen and the properties of foamed bitumen mixtures. Initially, four binders of different grades were evaluated for physical properties and foaming characteristics. The optimum foam content was then used to prepare foamed bituminous mixtures containing recycled asphalt pavement. These mixtures were evaluated for their mechanical properties, including indirect tensile strength, retained tensile strength and resilient modulus. The results from this laboratory study indicate that the properties of foamed bitumen and foamed mixtures are significantly influenced by the physical properties of the binder used, the quantity of binder and the recycled asphalt content. For a particular binder content in the mixture, use of a higher viscosity grade binder resulted in higher indirect tensile strength. A higher recycled asphalt pavement content in the mixture also resulted in higher indirect tensile strength. For all binder grades, a larger resilient modulus was observed for binder content the range of 2·3–2·5%.

Use of emulsion for warm mix asphalt

Abstract Due to increase in energy costs and emission problems in hot mix asphalt usually used, it brought a great interest to the researchers to develop the warm mix technology for pavement constructions. Commonly known as warm mix asphalt (WMA), it is a typical method in the bituminous paving technology, which allows production and placement of bituminous mixes at lower temperatures than that used for hot mix asphalt (HMA). The WMA involves an environmental friendly production process that utilises organic additives, chemical additives and water based technologies. The organic and chemical additives are normally very costly and still involve certain amount of environmental issues. These factors motivated the authors to take up this technology using simple, environment friendly and somewhat cost effective procedure. In this study, an attempt has been made to prepare warm mixes by first pre-coating the aggregates with medium setting bitumen emulsion (MS) and then mixing the semi-coated aggregates with VG 30 bitumen at a lower temperature than normally required. After a number of trials it was observed that mostly three mixing temperatures, namely temperatures 110 °C, 120 °C and 130 °C were appropriate to form the bituminous mixes with satisfactory homogeneity and consistency and as such were maintained throughout this study. Marshall samples for paving mixes were prepared using this procedure for dense bituminous macadam (DBM) gradings as per the specifications of Ministry of Road Transport and Highways (MORTH) and subsequently Marshall properties of the resultant mixes were studied with the main objective of deciding the different parameters that were considered for development of appropriate warm mix asphalt. In this study it has been observed that out of three mixing temperatures tried, the mixes prepared at 120 °C with bitumen-emulsion composition of 80B:20E for DBM warm mix, offer highest Marshall stability and highest indirect tensile strength (ITS), while satisfying the other Marshall parameters. It is also seen that the optimum binder contents for warm mixes are 5.1% with 80B:20E bitumen-emulsion composition for warm mix, prepared at 120 °C. The tensile strength ratio and retained stability parameters are also found to be reasonably satisfactory in such warm mixes, thus prepared.

Investigation on compressive strength development and drying shrinkage of ambient cured powder-activated geopolymer concretes

Geopolymer is an inorganic polymer binding material, generally formed by the reaction between aluminosilicate materials and alkali activator solution. Previous researches on geopolymer concrete around the world suggested that geopolymer concrete possess superior mechanical and durability properties over ordinary Portland cement (OPC) concrete, such as higher indirect tensile strength and resistance to sulphate attack. Generally, fly ash-based geopolymer concrete was cured in elevated temperature for higher early age strength because of their longer setting time in ambient temperature. Published engineering properties of geopolymer concrete cured at ambient temperature are not abundant. In this research, two types of powder-activated geopolymer binders were used as binding material. A detailed study of compressive strength and drying shrinkage of different grades (40, 50, 65 and 80 MPa) of geopolymer and OPC concrete with different workability levels (normal-workable and super-workable) were carried out. All the concrete specimens were cured at standard laboratory temperature. The compressive strength development of geopolymer concrete in early age was relatively lower than OPC concrete; however, the later age strength was significantly higher. The drying shrinkage of geopolymer concrete was similar to OPC concrete of same grade and complied with Australian Standard 1379; however, it was higher than estimated values from Australian Standard 3600. The drying shrinkage results of this study were higher than drying shrinkage of accelerated cured geopolymer concretes in previous investigations. Super workable concrete exhibited higher drying shrinkage than normal workable concrete of same grade.

Dynamic Tensile Strength of Coal under Dry and Saturated Conditions

The tensile failure characterization of dry and saturated coals under different impact loading conditions was experimentally investigated using a Split Hopkinson pressure bar. Indirect dynamic Brazilian disc tension tests for coals were carried out. The indirect tensile strengths for different bedding angles under different impact velocities, strain rates and loading rates are analyzed and discussed. A high-speed high-resolution digital camera was employed to capture and record the dynamic failure process of coal specimens. Based on the experimental results, it was found that the saturated specimens have stronger loading rate dependence than the dry specimens. The bedding angle has a smaller effect on the dynamic indirect tensile strength compared to the impact velocity. Both shear and tensile failures were observed in the tested coal specimens. Saturated coal specimens have higher indirect tensile strength than dry ones.

The Structural Properties Evaluation on Ultra-Thin Surfacing Hot Mixture Asphalt Concrete

Overlay as the conventional method to maintain the surface quality of pavement need a large number of fresh natural aggregate and bitumen due to the relatively thick layer and consequently the road geometric must be corrected, so that regarded as not environmentally friendly. The alternative solution is Ultra-Thin Surfacing Hot Mix Asphalt (UTSHMA) which has a thickness of 12-15mm. UTSHMA gradation is designed based on the highest Marshall Quotient value tested by performing Marshall Test of five variations gradation from Standard Specification Construction of Transport Systems. The Optimum Bitumen Content (OBC) obtained by Marshall Test. The bitumen used for this is 60/70 penetration. The several structural tests were performed on the best gradation at OBC consist of Marshall tests, Indirect Tensile Strength (ITS), Unconfined compressive strength (UCS) tests and water permeability test. The UTSHMA mixture with coarse gradation has the greatest Marshall Quotient at 6.35% OBC accompanied by the higher ITS and UCS properties compare to conventional asphalt concrete. The coefficient permeability of UTSHMA is lower than conventional AC, indicated that UTSHMA is more resistant to water penetration. The research concluded that UTSHMA has compromised the standard specification and has sufficient structural properties compare to conventional AC and can be regarded as structural layer of pavement for overlay and road preservation design.

폐비닐골재를 사용하는 아스팔트 콘크리트의 물리적 성질

PURPOSES : In this study, various laboratory tests were performed to investigate basic physical properties of the asphalt concrete which uses wasted vinyl aggregates. METHODS : The thermal conductivity, ultrasonic velocity, Marshall stability, flow, indirect tensile strength were measured according to binder content and wasted vinyl aggregate content. An experimental construction was performed to verify construct ability of the asphalt pavement using the wasted vinyl aggregates. RESULTS : The thermal conductivity and ultrasonic velocity decreased showing insulation effect by mixing more wasted vinyl aggregate, whereas stability and flow increased. The void ratio shows similar value regardless of the mixing ratio. The highest indirect tensile strength was measured at 2.5% of wasted vinyl aggregate content. The construct ability was verified by observing the process of mixing, placing, and compaction and the state of the pavement surface. CONCLUSIONS : The basic properties and construct ability of the asphalt concrete using the wasted vinyl aggregates were verified. The temperature according to pavement depth will be measured to verify the insulation effect of the wasted vinyl aggregates. In addition, amount of snowfall, snowmelt area, and ice adhesion strength will be analyzed quantitively.