The Influence of Coconut Shell as Coarse Aggregates in Asphalt Mixture

2016 ◽  
Vol 700 ◽  
pp. 227-237 ◽  
Author(s):  
Siti Nur Amiera Jeffry ◽  
Ramadhansyah Putra Jaya ◽  
Norhafizah Manap ◽  
Nurfatin Aqeela Miron ◽  
Norhidayah Abdul Hassan

Significant quantities of coconut shell (CS), a by-product of agriculture, can be used as an artificial source of coarse aggregates. In this study, four CSs were used as coarse aggregates replacement in asphalt concrete with 0%, 10%, 20%, 30%, and 40% weight volumes. The particle sizes of the CSs used as main coarse aggregates range from 5 mm to 20 mm. The Marshall Stability test shows that the optimum bitumen content for asphalt mixtures is 5.1%. The engineering properties investigated include the volumetric, dynamic creep, indirect tensile strength, and resilient modulus. Test results show that stability decreases with increasing CS content because of high water absorption. Considering that CSs absorb bitumen, a further detailed investigation is needed to assess the performance of modified bitumen on mixture. Furthermore, the use of CSs as coarse aggregates in asphalt concrete help increase the resilient modulus, stiffness, and indirect tensile strength up to 30%. Generally, a 10% replacement of coarse aggregates with CSs is the optimal limit.

2007 ◽  
Vol 34 (8) ◽  
pp. 902-911 ◽  
Author(s):  
Ibrahim M Asi ◽  
Hisham Y Qasrawi ◽  
Faisal I Shalabi

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.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7060
Author(s):  
Mohammad Alharthai ◽  
Qing Lu ◽  
Ahmed Elnihum ◽  
Asad Elmagarhe

This study investigates the substitution of conventional aggregate with a Florida washed shell in open-graded asphalt mixtures and evaluates the optimal substitution percentage in aggregate gradations of various nominal maximum aggregate sizes (NMASs) (i.e., 4.75, 9.5, and 12.5 mm). Laboratory experiments were performed on open-graded asphalt mixture specimens with the coarse aggregate of sizes between 2.36 and 12.5 mm being replaced by the Florida washed shell at various percentages (0, 15, 30, 45, and 100%). Specimen properties relevant to the performance of open-graded asphalt mixtures in the field were tested, evaluated, and compared. Specifically, a Marshall stability test, Cantabro test, indirect tensile strength test, air void content test, and permeability test were conducted to evaluate the strength, resistance to raveling, cracking resistance, void content, and permeability of open-graded asphalt mixtures. The results show that there is no significant difference in the Marshall stability and indirect tensile strength when the coarse aggregates are replaced with Florida washed shell. This study also found that the optimum percentages of Florida washed shell in open-graded asphalt mixture were 15, 30, and 45% for 12.5, 9.5, and 4.75 mm NMAS gradations, respectively.


2019 ◽  
Vol 5 (2) ◽  
pp. 320
Author(s):  
Gholam Hossein Hamedi

Several parameters affect asphalt mix performance against loading and environmental conditions. Minor changes in the filler amount or type can cause obvious changes in the asphalt mixture properties. Accordingly, in this research attempts have been made to optimally make asphalt mixture strong against loading and environmental conditions by changing the type, size and percentage of filler used in asphalt mixture. In this line, the effect of two types of cement and nano-silica fillers in two different percentages was investigated and compared as an alternative for part of the main filler in asphalt mixture samples made by two types of limestone and granite aggregate. Cement filler by 2% and 4% of the aggregate mass as the alternative for part of the main filler is added to stone materials before mixing with binder, but nano-silica filler by 2% and4 % of weight of the binder as the alternative for part of the main filler is added to binder and a modified and homogeneous binder is produced using a high speed mixer. In the following, considering the optimum binder content for each mixture, resilient modulus tests were conducted to determine the strength performance against loading and indirect tensile strength ratio was used to determine moisture sensitivity of asphalt mixtures. Results obtained from resilient modulus tests show that the use of nano-silica and cement has been capable of favorably improving the resilient modulus of samples containing these two types of fillers. The improvement of the resilient modulus of samples containing nano-silica is very significant. Additionally, the studies conducted based on the indirect tensile strength ratio show that both types of alternative fillers, especially cement has been capable of desirably improve the strength of asphalt mixtures against moisture damage.


2015 ◽  
Vol 76 (14) ◽  
Author(s):  
Tay Lay Ting ◽  
Ramadhansyah Putra Jaya ◽  
Norhidayah Abdul Hassan ◽  
Haryati Yaacob ◽  
Dewi Sri Jayanti

This paper provides a review of utilization coconut shell and coconut fiber in road construction. Coconut shell and coconut fiber are new waste materials used in highway industry. Some studies showed that coconut fiber can increase the stability, skid resistance and resilient modulus while coconut shell can improve the indirect tensile strength and static creep behavior of the modified asphalt pavement. In contrast, coconut fiber does not improve the fatigue life of the modified bituminous mixes. In general, the previous research illustrates that coconut shell and coconut fiber significantly improves the engineering properties of asphalt mixtures when mixed with modified bitumen.


Author(s):  
Shaban Ismael Albrka Ali ◽  
Riyadh Abdulwahid ◽  
Muhamed Laith Eidan ◽  
Nur Izzi Md Yusoff

Flexible pavements deteriorate and crack with time due to the frequent traffic load imposed upon it. Many studies have been done to predict the effects of frequent traffic load and environmental conditions on pavements in the effort to find the best pavement design which resist deterioration and ensure longer pavement service time. This study investigates the effect of mixing asphalt with varying percentages of nano calcium carbonate (CaCO3), namely 0, 2, 4, and 6 %. The mixtures were designed based on the Superpave mix design criteria. Investigation was done using several tests, namely resilient modulus, indirect tensile strength, moisture susceptibility, and dynamic modulus tests. Samples were subjected to aging to determine their resilient modulus. The results of the investigation show that resilient modulus and indirect tensile strength increased when higher percentages of nanoparticles were added to asphalt mixture, with improvement of 138 and 48.18% respectively. Modified binders showed up to 17% improvement in moisture susceptibility comparison to base asphalt mixture, while the result of dynamic modulus test showed that the stiffness of modified asphalt increased 76.69%. The investigation also found that adding 6% CaCO3 nanoparticles to asphalt produced modified asphalt with the best performance. In addition, the results show that the modified asphalt with CaCO3 is suitable for hot and humid regions (tropical countries) in the field of highways construction, as the modifier was able to mitigate the influences of high-temperature rutting and moisture damage.


2020 ◽  
Vol 20 (2) ◽  
pp. 125-136
Author(s):  
Sri Sunarjono ◽  
Nurul Hidayati ◽  
Adi Indra Pratama

Abstract This paper presents the results of research on the durability of Asphalt Concrete-Wear Asphalt (AC-WC) mixture using latex material to water immersion. Resistance to warm water immersion is intended to measure the durability of asphalt mixture in serving traffic loads against the influence of water and temperature factors. The use of latex material is intended to improve the performance of the mixture. This research uses a laboratory-scale test. The specimen of AC-WC added with latex was tested for its tensile strength using the Indirect Tensile Strength (ITS) test. Other specimens are immersed in water at 60°C with a continuous and periodic soaking system. The continuous immersion was carried out for 0, 24, 48, and 72 hours, while the periodic immersion was carried out for 12 hours soaked and 12 hours exposed alternately. The durability was analyzed using the Residual Strength Index indicator. The analysis shows that the addition of latex increased the tensile strength of the AC-WC mixture based on the ITS test results. The AC-WC mixture added with latex can increase its resistance to continuous and periodic immersion, by increasing the residual strength index and decreasing IKS with increasing immersion time. Continuous immersion has a greater impact on reducing IKS than periodic. In specimens without latex, the decrease in IKS values between continuous and periodic soaking has the same pattern, but in specimens with latex, the pattern is different. Keywords: asphalt concrete; latex; water immersion; Indirect Tensile Strength; Residual Strength Index.  Abstrak Makalah ini menyajikan hasil penelitian mengenai ketahanan campuran beraspal Asphalt Concrete-Wearing Course (AC-WC) yang menggunakan bahan lateks terhadap rendaman air. Ketahanan terhadap perendaman air hangat dimaksudkan untuk mengukur daya tahan campuran aspal dalam melayani beban lalu lintas terhadap pengaruh faktor air dan temperatur. Penggunaan bahan lateks dimaksudkan untuk memperbaiki kinerja cam-puran. Penelitian ini menggunakan uji skala laboratorium. Kekuatan tarik benda uji AC-WC dengan lateks diuji menggunakan uji Indirect Tensile Strength (ITS). Benda uji yang lain direndam dalam air bertemperatur 60oC dengan sistem rendaman menerus dan rendaman berkala. Metode perendaman secara menerus dilakukan selama 0, 24 jam, 48 jam, dan 72 jam, sedangkan rendaman secara berkala dilakukan 12 jam direndam dan 12 jam diekspose secara bergantian. Tingkat keawetan dianalisis menggunakan indikator Indeks Kekuatan Sisa (IKS). Hasil analisis menunjukkan bahwa penambahan lateks meningkatkan kekuatan tarik campuran AC-WC berdasarkan hasil uji ITS. Ketahanan terhadap perendaman menerus dan berkala, campuran AC-WC menggu-nakan lateks meningkat, dengan meningkatnya indeks kekuatan sisa dan menurunnya IKS dengan bertambah-nya lama rendaman. Perendaman secara menerus memberi dampak yang lebih besar dalam menurunkan IKS dibanding perendaman berkala. Pada benda uji tanpa lateks, penurunan nilai IKS antara rendaman menerus dan rendaman berkala memiliki pola yang sama, namun pada benda uji dengan lateks pola penurunan nilai IKS berbeda. Kata-kata kunci: campuran beraspal; lateks; rendaman air; Indirect Tensile Strength; Indeks Kekuatan Sisa.


2020 ◽  
Vol 1 (3) ◽  
pp. 27-32
Author(s):  
Saad Issa Sarsam

Asphalt concrete pavement practices repeated loading and environmental impacts and suffers distresses. Microcracks usually occurs at early stage of pavement life while the pavement can heal itself under controlled conditions. Microcrack healing process can be controlled and accelerated using various techniques. In this investigation, iron filling was implemented as partial substitute of sand to support the healing process while both induction and external heating techniques were adopted to control the healing using microwave and oven. Asphalt concrete specimens have been prepared with different percentages of iron filling and the corresponding required asphalt content. Specimens were subjected to repeated indirect tensile stresses for 600 and 1200 load repetitions. Specimens were allowed to heal using microwave and oven heating techniques. Specimens were subjected to another cycle of stress repetitions and the variation in the indirect tensile strength was detected before and after healing. The healing performance of the asphalt mixture specimens at different healing conditions was investigated by observing and testing the recovery of indirect tensile strength after healing. It was concluded that implementation of iron filling and induction heating by microwave can improve the healing and tensile properties of asphalt concrete as compared to the oven heating technique.


CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 370-384
Author(s):  
Hossein Noorvand ◽  
Kamil Kaloush ◽  
Jose Medina ◽  
Shane Underwood

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.


2019 ◽  
Vol 258 ◽  
pp. 04005
Author(s):  
Faizul Chasanah ◽  
Fajariesta Arta Putra

Asphalt concrete can be made through several methods including hot mix using Starbit E-55 asphalt as a binder and limestone as filler. This research aimed to determine the feasibility of the use of limestone as filler in AC-WC mixture and to identify the effects of limestone addition on the Marshall Characteristics, Durability, Indirect Tensile Strength (ITS), and Permeability. The first stage was to test the properties of materials consisting of aggregate, asphalt, and limestone. The second stage was to determine the optimum asphalt content with 0%, 25%, 50%, 75%, and 100% filler proportions, and the last stage was to conduct the Marshall, Immersion, ITS, and Permeability tests. The results showed that limestone has been in accordance with the performance requirements specified for a filler of AC-WC mixture using Starbit E-55 asphalt as a binder. There was a change in the Marshall characteristics of optimum asphalt content. The durability increased, and the ITS values of AC-WC mixture improved along with the increase in limestone proportion. However, the permeability test indicated that the mixture has a poor drainage feature towards water after variation in filler proportions was performed.


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