scholarly journals Recycling of Waste Materials Using Bitumen Emulsion for Road Pavement Stabilized Base Courses: a Laboratory Investigation

2021 ◽  
Vol 1203 (2) ◽  
pp. 022111
Author(s):  
Nicola Baldo ◽  
Matteo Miani ◽  
Fabio Rondinella ◽  
Marco Pasetto
Keyword(s):  
Tensile Strength ◽  
Laboratory Investigation ◽  
Environmental Sustainability ◽  
Mechanical Performance ◽  
Steel Slag ◽  
Indirect Tensile Strength ◽  
Waste Materials ◽  
Stiffness Modulus ◽  
Bitumen Emulsion ◽  
Indirect Tensile

Abstract The valorisation and reuse of waste materials can enhance the environmental sustainability of road constructions, especially by means of cold recycling techniques, which, moreover, allow to reduce polluting emissions in atmosphere. Among the various technological approaches, the use of bitumen emulsion to stabilize waste materials is very common, especially in case of reclaimed asphalt pavement (RAP) aggregates. However, even other types of waste materials could be considered using a Cold Central Plant Recycling (CCPR) approach. The paper discusses the main results of a laboratory investigation aimed to evaluate the mechanical performance of bitumen emulsion stabilized mixtures for road pavements base courses, prepared with RAP, steel slag, coal ash and glass wastes, used with various percentages. In a first step of the laboratory study, both physical and toxicological properties of each waste material have been investigated, in order to assess their environmental compatibility. Subsequently, an extensive mechanical analysis of the bitumen emulsion stabilized mixtures has been carried out in the laboratory, in terms of indirect tensile strength, indirect tensile stiffness modulus at three temperatures (10°C, 25°C, 40°C) and repeated load axial tests at 30°C. The moisture resistance of the mixes has been also investigated by means of indirect tensile strength tests carried out on soaked specimens. Very good results have been observed, depending on the mix composition: indirect tensile strength at 25 °C on dry specimens up to 0.52 MPa and stiffness modulus up to 4,056 MPa (at 25 °C, for a rise time equal to 124 ms). Therefore, it has been verified that the waste materials considered in the study can be successfully reused to completely substitute conventional aggregates in bitumen emulsion stabilized mixtures for road pavements base courses.

Use of steel slag aggregate in asphalt concrete mixes

2007 ◽  
Vol 34 (8) ◽  
pp. 902-911 ◽  
Author(s):  
Ibrahim M Asi ◽  
Hisham Y Qasrawi ◽  
Faisal I Shalabi
Keyword(s):  
Tensile Strength ◽  
Asphalt Concrete ◽  
Coarse Aggregate ◽  
Resilient Modulus ◽  
Steel Slag ◽  
Indirect Tensile Strength ◽  
Engineering Properties ◽  
Optimal Replacement ◽  
Indirect Tensile ◽  
Creep Modulus

There are three major steel-manufacturing factories in Jordan. All of their by-product, steel slag, is dumped randomly in open areas, causing many environmentally hazardous problems. This research was intended to study the effectiveness of using steel slag aggregate (SSA) in improving the engineering properties of locally produced asphalt concrete (AC) mixes. The research started by evaluating the toxicity and chemical and physical properties of the steel slag. Then 0%, 25%, 50%, 75%, and 100% of the limestone coarse aggregate in the AC mixes was replaced by SSA. The effectiveness of the SSA was judged by the improvement in indirect tensile strength, resilient modulus, rutting resistance, fatigue life, creep modulus, and stripping resistance of the AC samples. It was found that replacing up to 75% of the limestone coarse aggregate by SSA improved the mechanical properties of the AC mixes. The results also showed that the 25% replacement was the optimal replacement level. Key words: steel slag aggregate, asphalt concrete, Superpave, indirect tensile strength, fatigue, rutting, creep.

Evaluation of Factors Influencing strength of Foamed Bitumen Stabilised Mix

2014 ◽  
Vol 70 (4) ◽  
Author(s):  
Mohd Rosli Hainin ◽  
Mohd Yazip Matori ◽  
Oluwasola Ebenezer Akin
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Resilient Modulus ◽  
Indirect Tensile Strength ◽  
Asphalt Pavements ◽  
Curing Time ◽  
Bitumen Emulsion ◽  
Indirect Tensile ◽  
Foamed Bitumen

Over recycling of asphalt pavements involves mixing of existing pavement material with stabilizing agent such as foamed bitumen, bitumen emulsion, cement or lime and placed on the milled pavement and compacted. The strength of foamed bitumen stabilized mix is influenced by factors such as cement content, moisture level and curing time. It was found that the strength in terms of resilient modulus, Unconfined Compressive Strength (UCS) and Indirect Tensile Strength (ITS) values, increased with curing time and percentage of active filler. It was also found that the maximum strength in terms of resilient modulus, Unconfined Compressive Strength (UCS) and Indirect Tensile Strength (ITS) was not at Optimum Moisture Content (OMC) and the strength decreased as the RAP proportion increased

scholarly journals Asphalt concrete mixtures with addition of reclaimed asphalt pavements

2021 ◽  
Author(s):  
Piotr Zieliński
Keyword(s):  
Tensile Strength ◽  
Asphalt Concrete ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Asphalt Pavements ◽  
Stiffness Modulus ◽  
Reclaimed Asphalt ◽  
Concrete Mixtures ◽  
Indirect Tensile ◽  
Reclaimed Asphalt Pavements

The effect of using reclaimed asphalt pavements (RAP) to asphalt concrete mixtures besides their utilization is to reduce the amount of the new bituminous binder and aggregate added to hot mix asphalt. This publication presents studies on asphalt mixtures with an increased up to 40% amount of RAP additive with the simultaneous use of 2 types of added bitumen, i.e. 35/50 and PMB 25/55-60. The aim of the paper is the evaluation of the basic mixture properties in a wide range of operating temperatures, as a part of the AC testing at high temperatures, the resistance to rutting at 60° C and indirect tensile strength at 40° C. The assessment of properties at intermediate operating temperatures is based on indirect tensile tests, including: elastic stiffness modulus at 5° C, 15° C and 30° C and static strength at 25° C. The low temperature properties have been tested in water and frost resistance tests by indirect tensile strength ratio. The results of the study were subjected to the analysis of the statistical significance of differences, which showed an improvement in the resistance of AC with the addition of RAP to the formation of permanent deformations and an increase in the stiffness modulus as well as indirect tensile strength. There was no adverse effect of the RAP additive on asphalt mixtures resistance to water and frost action.

scholarly journals The Use of Steel Slag as Substitution of Coarse Aggregate on Indirect Tensile Strength and Marshall Properties of AC-WC

2021 ◽  
Vol 933 (1) ◽  
pp. 012004
Author(s):  
A A Nugraha ◽  
M Fauziah ◽  
Subarkah
Keyword(s):  
Tensile Strength ◽  
Coarse Aggregate ◽  
Permanent Deformation ◽  
Steel Slag ◽  
Fatigue Cracking ◽  
Indirect Tensile Strength ◽  
Coarse Aggregates ◽  
Experimental Laboratory ◽  
Indirect Tensile ◽  
Polymer Modified Asphalt

Abstract High traffic levels on road can causing road damage, especially cases of permanent deformation and fatigue cracking. One solution is to utilize waste of material, such as steel slag as coarse aggregate and polymer modified asphalt as binding material. This paper explores experimental laboratory investigation on the use of steel slag on Marshall characteristics and indirect tensile strength of AC-WC mixture by using Starbit E-60 and Pen 60/70. Laboratory works begin with physical testing of material, then, finding the optimum bitumen content (OBC) for each type of the mixtures. Finally, Marshall Standard and indirect tensile strength (ITS) at OBC were conducted. Results shows that the use of steel slag for AC-WC mixture are proven to improve resistance to permanent deformation as well as fatigue cracking. Substitution of steel slag for coarse aggregates were able to increase Marshall stability, Marshall Quotient and indirect tensile strength (ITS) of the mixtures, however, it slightly decreases the volumetric performance of mixture, such as voids in total mixes become higher and voids filled with asphalt as well as voids in mineral aggregates tend to decrease.

scholarly journals Rejuvenation Mechanism of Asphalt Mixtures Modified with Crumb Rubber

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 370-384
Author(s):  
Hossein Noorvand ◽  
Kamil Kaloush ◽  
Jose Medina ◽  
Shane Underwood
Keyword(s):  
Tensile Strength ◽  
Dynamic Loading ◽  
Creep Compliance ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Indirect Tensile Strength ◽  
Laboratory Evaluation ◽  
Strength Testing ◽  
Noise Mitigation ◽  
Indirect Tensile

Asphalt aging is one of the main factors causing asphalt pavements deterioration. Previous studies reported on some aging benefits of asphalt rubber mixtures through laboratory evaluation. A field observation of various pavement sections of crumb rubber modified asphalt friction courses (ARFC) in the Phoenix, Arizona area indicated an interesting pattern of transverse/reflective cracking. These ARFC courses were placed several years ago on existing jointed plain concrete pavements for highway noise mitigation. Over the years, the shoulders had very noticeable and extensive cracking over the joints; however, the driving lanes of the pavement showed less cracking formation in severity and extent. The issue with this phenomenon is that widely adopted theories that stem from continuum mechanics of materials and layered mechanics of pavement systems cannot directly explain this phenomenon. One hypothesis could be that traffic loads continually manipulate the pavement over time, which causes some maltenes (oils and resins) compounds absorbed in the crumb rubber particles to migrate out leading to rejuvenation of the mastic in the asphalt mixture. To investigate the validity of such a hypothesis, an experimental laboratory testing was undertaken to condition samples with and without dynamic loads at high temperatures. This was followed by creep compliance and indirect tensile strength testing. The results showed the higher creep for samples aged with dynamic loading compared to those aged without loading. Higher creep compliance was attributed to higher flexibility of samples due to the rejuvenation of the maltenes. This was also supported by the higher fracture energy results obtained for samples conditioned with dynamic loading from indirect tensile strength testing.

scholarly journals Evaluations of Nano-Sized Hydrated Lime on the Moisture Susceptibility of Hot Mix Asphalt Mixtures

2012 ◽  
Vol 174-177 ◽  
pp. 82-90 ◽  
Author(s):  
Ju Nan Shen ◽  
Zhao Xing Xie ◽  
Fei Peng Xiao ◽  
Wen Zhong Fan
Keyword(s):  
Tensile Strength ◽  
Experimental Design ◽  
Hot Mix Asphalt ◽  
Hydrated Lime ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Moisture Resistance ◽  
Strength Ratio ◽  
Moisture Susceptibility ◽  
Indirect Tensile

The objective of this study was to evaluate the effect of nano-sized hydrated lime on the moisture susceptibility of the hot mix asphalt (HMA) mixtures in terms of three methodologies to introduce into the mixtures. The experimental design for this study included the utilizations of one binder source (PG 64-22), three aggregate sources and three different methods introducing the lime. A total of 12 types of HMA mixtures and 72 specimens were fabricated and tested in this study. The performed properties include indirect tensile strength (ITS), tensile strength ratio (TSR), flow, and toughness. The results indicated that the nano-sized lime exhibits better moisture resistance. Introducing process of the nano-sized lime will produce difference in moisture susceptibility.

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