scholarly journals Effect of Hydrated Lime on Indirect Tensile Stiffness Modulus of Asphalt Concrete Produced in Half-Warm Mix Technology

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4731
Author(s):  
Mateusz M. Iwański
Keyword(s):  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Active Agent ◽  
Hydrated Lime ◽  
Partial Replacement ◽  
Stiffness Modulus ◽  
Limestone Filler ◽  
Tensile Stiffness ◽  
Lime Content ◽  
Indirect Tensile

Half-warm mix asphalt (HWMA) mixtures can be produced at temperatures ranging from 100 °C to 130 °C, depending on the production methods used. The lowest mixing temperature can be achieved by using water-foamed bitumen. The mixture should be characterized by a long service life, defined by the resistance to permanent deformation and high stiffness modulus at temperatures above zero. It is therefore important to ensure the adequately high quality of the bitumen binder. Bitumen 50/70 was provided with appropriate quality foaming characteristics (expansion ratio, ER, half-life, t1/2) by adding a surface-active agent (SAA) at 0.6 wt % before foaming. Then asphalt concrete (AC) 8 S was designed and produced with the recommended water-foamed binder. Hydrated lime, an additive substantially affecting asphalt concrete mechanical parameters, was used at 0, 15, 30, and 45 wt % as a partial replacement for the limestone filler. The influence of the amount of hydrated lime on the content of voids, indirect tensile stiffness modulus at −10 °C, 0 °C, +10 °C, +20 °C, and +30 °C, and the resistance to permanent deformation was investigated. Statistical analysis of the test results showed the quantity of 30% to be the optimum hydrated lime content. The AC 8 S resistance to permanent deformation was determined at the optimum hydrated lime content. The comprehensive evaluation revealed a synergistic effect between bitumen 50/70, modified before foaming with 0.6 wt % SAA and 30 wt % hydrated lime as the limestone filler replacement, and the half warm mixture AC 8 S, in terms of the standard requirements and durability of the HWMA concrete in pavement applications.

scholarly journals KARAKTERISTIK MARSHALL DAN STIFFNESS MODULUS PADA LAPIS TIPIS CAMPURAN ASPAL PANAS DENGAN PENAMBAHAN CRUMB RUBBER

2019 ◽  
Vol 7 (4) ◽  
Author(s):  
Maulana Andhika Pratama Ilyas ◽  
Ary Setyawan ◽  
Djumari Djumari
Keyword(s):  
Hot Mix Asphalt ◽  
Crumb Rubber ◽  
Stiffness Modulus ◽  
Tensile Stiffness ◽  
Marshall Test ◽  
Indirect Tensile

<p>Penggunaan lapis tipis campuran aspal panas (<em>Thin Surfacing Hot Mix Asphalt</em>) merupakan salah satu alternatif yang dapat mengantisipasi masalah ketebalan perkerasan jalan. <em>Crumb rubber (CR) </em>merupakan limbah hasil dari vulkanisir ban yang merupakan masalah serius bagi lingkungan dan penggunaan <em>crumb rubber </em>lebih murah daripada karet alam atau jenis-jenis polymer yang lain. Tujuan dari penelitian ini adalah untuk mengkaji kadar aspal optimum pada <em>Thin Surfacing Hot Mix Asphalt </em>dengan penambahan <em>crumb rubber </em>dan tanpa penambahan <em>crumb rubber</em> serta membandingkan pengaruh penambahan <em>crumb rubber</em> terhadap karakteristik <em>stiffness modulus</em> pada masing masing campuran. Dengan metode eksperimental menggunakan metode <em>Marshall </em>dapat ditentukan nilai stabilitas untuk mengetahui kadar aspal optimum masing masing campuran yang akan dilaksanakan di Laboratorium Jalan Raya Universitas Sebelas Maret Surakarta. Selanjutnya, metode <em>Indirect Tensile Stiffness Modulus</em> dapat digunakan untuk menentukan besarnya <em>stiffness modulus</em> akan dilaksanakan di Laboratorium Perkerasan Jalan Pusjatan Kementerian Pekerjaan Umum dan Perumahan Rakyat di Bandung serta di Laboratorium Jalan Raya Universitas Udayana Bali. Aspal yang digunakan adalah aspal penetrasi 60/70 dengan penambahan crumb rubber sebesar 0%, 0,5%, 1,0% dan 1,5% dari berat total campuran. Dari hasil <em>marshall test</em> diperoleh kadar aspal optimum yaitu untuk masing-masing kadar <em>crumb rubber</em> 0%, 0,5%, 1,0% dan 1,5% yaitu 5,41%, 5,50%, 5,39% dan 5,52%. <em>Thin Surfacing Hot Mix Asphalt</em> dengan penambahan <em>Crumb Rubber</em> 1% menurunkan nilai Kadar Aspal Optimum sebesar 0,4% dan meningkatkan nilai stabilitas sebesar 2% dibandingkan dengan <em>Thin Surfacing Hot Mix Asphalt</em> tanpa penambahan <em>Crumb Rubber</em> 1%. Sedangkan untuk uji ITSM dari <em>Thin Surfacing Hot Mix Asphalt</em> dengan penambahan <em>Crumb Rubber</em> 1% menurunkan nilai <em>Stiffness Modulus</em> sebesar 51,3% untuk suhu 20°C, dan meningkatkan nilai <em>Stiffness Modulus</em> sebesar 30,7% untuk suhu 40°C<em>. </em>Selain itu, <em>Thin Surfacing Hot Mix Asphalt</em> dengan penambahan <em>Crumb Rubber </em>1% mempunyai ketahanan terhadap suhu lebih besar yaitu hanya 75% penurunan nilai <em>stiffness modulus</em> dari suhu 20°C ke suhu 40°C dibandingkan dengan <em>Thin Surfacing Hot Mix Asphalt</em> tanpa penambahan <em>Crumb Rubber</em> 1% yaitu<em> </em>sebesar 91%<em>.</em></p>

scholarly journals Study of the Stiffness of the Bitumen Emulsion Based Cold Recycling Mixes for Road Base Courses

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5473
Author(s):  
Katarzyna Konieczna ◽  
Piotr Pokorski ◽  
Wojciech Sorociak ◽  
Piotr Radziszewski ◽  
Dawid Żymełka ◽  
...  
Keyword(s):  
Road Construction ◽  
Reclaimed Asphalt Pavement ◽  
Stiffness Modulus ◽  
Pavement Rehabilitation ◽  
Reclaimed Asphalt ◽  
Bitumen Emulsion ◽  
Potential Benefits ◽  
Indirect Tensile ◽  
Reduction Of Energy Consumption ◽  
Cold Recycling

The benefits of the use of cold recycling mixtures (CRMs) in pavement rehabilitation are associated with both the reduction of natural resource consumption by replacing them with recycled materials and the reduction of energy consumption during their production and paving. The evolution of the stiffness of CRMs in road construction and the fatigue life of pavements with CRM base layers are still being investigated. In this paper, CRMs with 1% cement content, called bitumen-stabilized materials with bitumen emulsion (BSM-Es), were examined. Mixtures that were differentiated in terms of Reclaimed Asphalt Pavement (RAP) content, as well as the amount and type of bitumen emulsions, were subjected to indirect tensile stiffness modulus (ITSM) tests at 5 °C, 13 °C, and 20 °C. The thermal sensitivities of the BSM-E mixtures were analyzed. BSM-E mixture stiffness modulus levels at various temperatures were determined using a statistical approach. On the basis of the results obtained, a discussion on the mechanistic-empirical design of flexible pavements with BSM-E base layers is presented. The potential benefits of using BSM-E materials in road construction in certain aspects of pavement life are indicated.

scholarly journals Stiffness Modulus of Asphaltic Concrete Incorporating Coir Fibre and Subjected to Aging

2018 ◽  
Vol 65 ◽  
pp. 02003
Author(s):  
Abdullahi Ali Mohammed ◽  
Ramadhansyah Putra Jaya ◽  
Étienne Joseph Marie Delbrel ◽  
Choong Wee Kang ◽  
Sien Ti Kok ◽  
...  
Keyword(s):  
Stiffness Modulus ◽  
Modified Asphalt ◽  
Indirect Tensile Test ◽  
Coir Fibre ◽  
Performance Response ◽  
Short And Long Term ◽  
Indirect Tensile ◽  
Repeated Load ◽  
The Impact

The aim of this paper is to investigate the performance response of a set of coir fibre modified asphalt samples subjected different ageing conditions and containing three different fibre contents. The laboratory experimental programs are indirect tensile test at 25°C and repeated load axial test at 40°C. The results showed that the fibres improved the mixture’s performance. The main findings obtained at 25°C for short and long-term ageing reveal that low fibre content at around 0.3% per aggregate weight display a stiffness modulus up to 14% higher than that of unmodified mixtures, hence showing that fibres may improve the bearing capacity and rut-resistance of asphalt mixtures. Conversely, as the amount of fibre increases to 0.5% and 0.7%, the stiffness decreases to the point of becoming unacceptably low, almost 80% lower than unmodified mixes stiffness. However the data also reveal that high fibre contents at 0.5% and above completely neutralize the impact of ageing on the mixture, indicating that fibre-modified mixtures would yield longer lives.

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