Compaction Characteristics and Bearing Capacity of Recycled Materials for Road Construction

Author(s):  
Carlo Rabaiotti ◽  
Markus Caprez
2020 ◽  
Vol 7 ◽  
Author(s):  
Alessandra Bonoli ◽  
Anna Degli Esposti ◽  
Chiara Magrini

The concept of sustainability in the road construction sector is a complex issue because of the various steps that contribute to the production and release of greenhouse gas (GHG) emissions. Addressing this issue, the European Commission has put various policy initiatives in place to encourage the construction industry to adopt circular economy (CE) and industrial symbiosis (IS) principles e.g., the use of recycled materials. Cooperativa Trasporti Imola (CTI), a company located in the Emilia-Romagna region (Italy), has been chosen for the current case study to examine practices, management, and the industrial symbiosis network among various companies in the road construction and rehabilitation sector. In this regard, the use of steel slags, obtained by an electric arc furnace (EAF), and reclaimed asphalt pavement (RAP), obtained by the deconstruction and milling of old asphalt pavement have been investigated. Two mixtures of recycled hot Mix Asphalt (HMA) i) were prepared incorporating different recycled material percentages for the wearing and binder course, respectively, ii) were characterized in terms of size distribution, strength modulus and volumetric properties, iii) and finally were compared to the performances of two mixtures entirely designed by virgin materials for the wearing and binder course, respectively. Therefore, the Life Cycle Assessment (LCA) tool was chosen to evaluate the environmental impacts that affect the designed road life cycle. The results show that recycling RAP and EAF slags in a CTI batch plant provides benefits by reducing the consumption of virgin bitumen and aggregates and by reducing CO2eq emissions. Finally, practical implications on the use of recycled materials in new asphalt mixtures from a life cycle and industrial symbiosis perspective are provided.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256190
Author(s):  
Zhen Liu ◽  
Aobo Zhang ◽  
Jiangping Xu ◽  
Cuiying Zhou ◽  
Lihai Zhang

The geosynthetic-reinforced pile-supported embankment (GRPSE) system has been widely used in road construction on soft soil. However, the application of the GRPSE system is often restricted by its high-cost. The reason is that they are designed for bearing control as defined in the past. During the construction process, the pile spacing is reduced to meet the requirements for the embankment bearing capacity and settlement. These factors cause the membrane effect to not be exploited. As a result, the utilization efficiency of the bearing capacity of the soil between the piles is low and the project cost is high. Therefore, in order to solve the problem of insufficient bearing capacity of soil between piles, we established a settlement calculation model of soil between piles based on membrane effect. The model considers the relationship between the geosynthetic reinforcement (GR) and the pile spacing. Based on the obtained model, a method for optimizing the soil bearing capacity of GRPSEs is proposed. By controlling the settlement of soil between piles, the bearing capacity of soil between piles and the membrane effect of embankment can be fully utilized. Therefore, the project cost can be reduced. Finally, the method is applied to field tests for comparison. The results show that the method is reasonable and applicable. This method can effectively exploit the membrane effect and improve the utilization efficiency of the bearing capacity of the soil between piles. An economical and reasonable arrangement scheme for the piles and GR was obtained. This scheme can not only ensure the safety of the project, but also fully utilize the bearing capacity of the soil between the piles and provide a new method for engineering design.


The search for alternative methods of replacing steel reinforcement in load-bearing reinforced concrete structures with composite polymer reinforcement is an urgent scientific and practical task. Composite reinforcement (basalt-plastic, fiberglass) is an economically viable alternative to steel reinforcement; it possesses high tensile strength and chemical resistance, light weight (more than 4 times lighter than the steel ones), low thermal conductivity, radio transparency, dielectric properties. Such properties make it possible to use this type of reinforcement of concrete structures in civil, industrial, and road construction. Only in recent years, the specialists in Uzbekistan have paid special attention to the need for composite polymer reinforcement in construction. This type of reinforcement makes it possible to increase the service life of concrete structures and the building as a whole and to reduce the country's dependence on imports of steel reinforcement. At present the production of basalt-plastic reinforcement is localized in the country – its fiber is made from local basalt. For the possibility of industrial application of composite polymer reinforcement in construction, it is necessary to establish a relationship between a customer, a designer, and a manufacturer. For a customer, the project must be economically profitable, a designer must understand the physical and mechanical properties of the reinforcement and know the regulatory base, and a manufacturer must be interested in producing quality units and assemblies in accordance with the interstate standards, and be sure that the reinforcement produced by him will be in demand. The high deformability of structures caused by the low modulus of elasticity of composite reinforcement does not allow the manufacture of structures that work as bending and eccentrically compressed elements, embedded in reinforced concrete; however, it is noted that such reinforcement can be used in structures for which the requirements for the second group of limiting states are not determinant. The national standards acting in the CIS countries and other states limit the scope of application of composite polymer reinforcement in concrete structures in industrial objects of the economic complex. An analysis of the actual operation of prefabricated road panels, taking into account the low deformation characteristics of basalt-plastic reinforcement, showed the possibility of replacing steel reinforcement with a composite polymer one according to the criterion of uniform strength in terms of design tensile strengths while maintaining the number of working reinforcement bars and their location in reinforcing units. The results of testing the pilot panels of the road surface (prefabricated ones) reinforced with basalt-plastic reinforcement were considered to determine their crack resistance and bearing capacity. The test results of experimental road panels show that the bearing capacity not only decreased but substantially increased. The high corrosion resistance of basalt-plastic reinforcement, when used in road panels, contributes to an increase in the service life of such panels, since the values of crack opening under operational loads are set lower than the permissible limit values. The results of this study show that it is possible to expand the scope of industrial application of basalt-plastic reinforcement in the production of precast concrete structures, for example, for road construction. To do this, it is necessary to create a regulatory framework based on the results of relevant research work.


2021 ◽  
Vol 5 (2) ◽  
pp. 60-73
Author(s):  
Ahmad Ravi ◽  
Hurul 'Ain ◽  
Betti Ses Eka Polonia ◽  
M. Hanif Faisal

Ketapang and Kayong Utara Regency have road construction that often suffers damage before the planned life age caused by the behavior of expansive clay. The subgrade is a fundamental structure in building road construction because the subgrade will support traffic loads or construction loads. The strength and durability of the pavement structure road will depend on the properties and bearing capacity of the subgrade. Practically soil stabilization is a reinforcement engineering against foundation or subgrade by using mixed materials. Therefore, different soil improvement variations are needed. Based on the test result, the CBR value of Sukadana initially gets a 2.95% point. The CBR value for the 6% and 10 % mixture, respectively, gets 17.14% and 25.02%. The CBR value of Sungai Melayu Rayak originally get 4.65% point. Then, for the 6% and 10% mixture, the CBR values increased by 13.78% and 18%. The value of the bearing capacity of the highway soil construction can be know from the results of CBR testing on each variation. The CBR also can measure the strength of the soil. The addition of cement to the earth tends to increase the bearing capacity of the ground. It is because cement can function as a binder between soil particles with chemical compounds contained in cement.


2018 ◽  
Vol 181 ◽  
pp. 01001
Author(s):  
Hasriana ◽  
Lawalenna Samang ◽  
Tri Harianto ◽  
M.Natsir Djide

The problem that is often faced in a road construction is a soil subgrade (soft soil). If the subgrade has a low bearing capacity, causing the soil to decrease greatly, so the road construction will quickly be damaged. Method to overcome the problem is bio stabilization with bacteria utilization. The purpose of this research is to know the bearing capacity improvement of soft soil as subgrade layer with bacteria solution of bacillus subtilis. Tests include soil physical and mechanical properties, compaction parameters and CBR tests. This test is based on ASTM for each test. Variations in addition of bacterial solution were 2%, 4%, 6%, 8% and 10% of dry soil weight with 7 days curing time. The results showed that the maximum value of CBR of soft soil was found at 39% on 6% bacterial solution. Increased CBR value from 2.8% to 39% or 13 times than untreated soil. This shows the use of bacterial concentration solution on soft soil significantly increases the bearing capacity.


2020 ◽  
Vol 841 ◽  
pp. 171-176
Author(s):  
Sararat Kwunjai ◽  
Peerapong Jitsangiam ◽  
Teewara Suwan ◽  
Damrongsak Rinchumphu ◽  
Hemwadee Thongchua ◽  
...  

To be more sustainable in the road construction industry, the rock-based geopolymer concept should be applied with an aim to create a geopolymer-based road structural layer. The research program studied on the geopolymer for road construction was newly established at Chiang Mai University, Thailand. This study concentrated in a preliminarily evaluation of strength performance and compaction characteristics of crushed rock-based geopolymer (CR-GP) to partially or totally replace the usage of ordinary Portland cement (OPC) as a road stabilizing agent. The standard crushed rock (CR), complying with the standard of road base materials, was obtained from a real construction field. The experiment on CR gradation, compaction and compressive strength were carried out. The results showed that CR of a finer grading curve with higher surface areas tended to better react with alkaline activators, resulting in relatively high compressive strength. The mechanical modification with compaction is one of the simplest methods for strength improvement. It found that higher compactive efforts (the modified compaction), higher densification than that of the standard compaction, corresponding to the compaction theory of soil mechanics. CR-GP having an ideal (reconstituted) grading curve achieved higher compressive strength than that of the standard grading one of a well-graded pattern. Overall, it could be concluded CR-GP has intrinsic compaction characteristics of which at its optimum point of compaction, CR-GP could address the minimum requirement for road standard in terms of compressive strength, by which it could be used as an alternative material in replacing the consumption of OPC.


2011 ◽  
Vol 75 (4) ◽  
pp. 1276-1284 ◽  
Author(s):  
Dong-Hee Kang ◽  
Satish C. Gupta ◽  
P. R. Bloom ◽  
Andry Z. Ranaivoson ◽  
Ruth Roberson ◽  
...  

2019 ◽  
Vol 3 (1) ◽  
pp. 1-6
Author(s):  
Muhammad Firdaus ◽  
Muhammad Suhaimi ◽  
Fathurrozie Fathurrozie

Dalam makalah ini mendiskusikan  mengenai  pengembangan  fasilitas infrastruktur  umum di Komplek  Bumi Mas Lestari  Perdagangan  Banjarmasin  yaitu Pembangunan  Jalan lingkungan  yang secara khusus  meninjau  bagian tanah dasar dan ketebalan  timbunan  sirtu. Perhitungan  daya dukung  tanah dasar mengacu kepada input nilai CBR metode SNI yaitu index dan engineering  properties,  uji kepadatan tanah standar proctor di laboratorium dan uji CBR Laboratorium. Studi penelitian terhadap tanah dasar yang dibandingkan adalah tanpa dan dengan penggunaan penambahan semen 9% terhadap tanah asli lanau lunak berlempung  plastisitas  rendah,  hasil  yang  dapat  mewakili  untuk  perbandingan  nilai  kelayakan  subgrade adalah pemenuhan terhadap ketentuan nilai CBR subgrade pada Spesifikasi Umum Bina Marga sebesar minimum 6% pada pelaksanaan timbunan jalan, karena antara nilai CBR tanah dasar asli yang dihasilkan 4% dan setelah distabilisasi menggunakan semen menghasilkan  peningkatan 9,8%, tanah dasar telah memenuhi persyaratan   dan  dapat  digunakan   menjadi  bagian  dari  konstruksi   perkerasan   jalan  diatasnya  sebagai penopang. Abstract This  paper  discuss  infrastucture  development  of  road  transportation  in  Bumi  Mas  Lestari Housing   Compex   Construction   mainly   Road   access   facility   construction   mainly   for   subgrade   and embankment of  thickness materials. The calculation of theoretical bearing   capacity of subgrade based on Standar Nasional Indonesia (SNI), including Proctor Standard and CBR test laboratory.research  focus on cement mixing between natural condition of subgrade using 9% cement ratio in silty clayey low plasticity type of soil sample. Conduct Bina Marga Specification of Road Construction,  minimum CBR Design is 6% was allowed with 9,8% CBR Design after mixing cement as stabilitation of 4% CBR design before.


Author(s):  
S Fischer

Purpose. To determine the relationship between water content of continuously graded granular supplementary layers for railway substructure and their inner shear resistance and load bearing capacity. Methodology. Four different samples were produced as standard granular products from andesite. Two of them are common base courses for road construction in Hungary, the other two are common railway supplementary layers. The author performed laboratory measurements (multi-level shear box tests) that are adequate for the evaluation of inner shear resistance. The measurements of load bearing capacity and Proctor tests were executed in the laboratory of Colas Hungaria Ltd. The author performed measurements with the optimal water content values of each sample, as well as lower and higher values than them. This can show how the given granular material is sensible to the change of water content. Findings. It was proved that the granular supplementary layers, which are standardized products in road construction (as base courses), also seems to be adequate in railway construction; they are not so sensible to the variation of their water content. It does not mean that the other two granular layers are not adequate for railway substructures, but the application of road products have to be considered as substitute products. Originality. The author tried to emphasize the adequacy of rock mining for construction of ballasted railway tracks, as well as the optimal use of mineral wealth in every country with its results. Practical value. The obtained results of the present paper can be useful in the area of rock mining, and railway infrastructure engineering. During construction procedures the optimal water content values should be taken into considerations for compaction to be able to reach maximal compactness (density), but too high water content has to be avoided, which is based on the results. They can be also considered in the design phase.


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